Bio Exam
Bio - Unit 1 Notes
Biodiversity
LESSON 1 - Intro to Diversity
Ecosystem biodiversity – different types of habitats, communities and ecological processes (ex. tropical deserts, alpines, tundra, ocean)
There are microhabitats within an ecosystem which sustain different purposes (ex. Forest has several layers which the environment fosters different living things)
Species biodiversity – how many species do we have → taking number of known species and number of new species, estimated to be around 100 million species
Genetic biodiversity – within one species (ex. humans)
Reasons to preserve biodiversity: aesthetic, medicine, food, interactions
What to do to protect it: patrolling reserves, planting species, explore
Why Study Biodiversity?
Interconnectedness → the effects that the decline of a species will have on another species
→ all living things interact with each other – eating, services
→ ex. Egrets team up with carnivores to eat their parasites and see further, carnivores share food supply and protect
Evolutionary change → how organisms came to exist and change overtime
Enable our planet to continue sustaining/ preserve life
More biodiversity = more stability = more the ecosystem can adapt to change → the more species, the better an ecosystem can withstand climate change, disease and pest infestations
What Destroys Biodiversity?
Habitat loss
Introducing invasive species
Overexploitation (hunt, cut trees)
Pollution of water, air, soil
Climate change & global warming
Why do we need Biodiversity?
Ecosystem stability
Food supply
Medicines
Tourism/forest industry
Natural earth cycles
Extinction
Extinction is normal as species get replaced → 10-100 species/yr is normal
Bad when mass extinction → estimated 27,000/yr
How Can We Help?
Habitat restoration – if we can figure out what we do to harm the environment, we can fix it
Zoos and Captive Breeding – breeding of endangered species and then bringing them back to the environment
Protect habitats and species – from poachers or setting preserve zones
Reduce climate change and fossil fuels
LESSON 2 - Classifying and Sorting Living Things (Taxonomy)
Taxonomy = the science/study of naming, classifying and identifying species
3 Domains of All Life:
Bacteria
Archaea
Eukarya (complicated cells with a nucleus)
Carolus Linnaeus:
Swedish botanist
1707-1778
Good – he divided and classified all living things and created a formal system
Bad – he did this with all living things, including humans (racism invented → listed characteristics of groups of humans)
Because of him → invented 1.2 million species identified
Levels of Classification:
Doctor King Phillip Calls Out For Golden Shekels
Domain
Kingdom
(Ex. Animalia → multicellular, animal cells, eat food, live birth, hair)
Phylum
Class
Order
Family
Genus
Species
LESSON 3: Scientific Naming - Binomial Nomenclature
Each organism’s name has 2 parts:
Genus (Capitalized)
Species (lower case)
Problem with common names:
Can’t name by describing (ie. single celled organisms)
Misleading
Do not have a system (ie. looks, colour, geography)
Different parts of the world have different names for something
Proper names:
Embedded list of criteria
No language barrier
Only one word for something
Scientific Naming:
Use characteristics to name (ie. all cats are in the Felis genus)
How to decide if 2 individuals are the same species?
Morphology → similar shape, size, structure (do they look similar)
Not the best/most accurate
Biology → they can naturally produce viable offspring (fully functional babies)
Preferred definition
Does not work for species that reproduce asexually or that do not exist
Phylogeny → the study of relationships – close evolutionary relationship (did they evolve together)
*** All these traits must be observable
Ex. A mule is the result of a donkey and a horse, but it cannot reproduce (sterile) therefore does not have a scientific name
A species is a group of individuals with similar characteristics that produce real viable offspring
LESSON 4 - Phylogeny – How Species are Related
Phylogeny = a visual representation of the evolutionary history of a species over time
If we know what species are related → better testing and better medical breakthroughs (vaccines, drugs)
Phylogenetic Tree
Starts at the root (the past)
The width of the tree looks at how different species are
Nodes
Clades → the most closely related
Outgroups
Evidence of Evolutionary Relationships
How much DNA in common
Anatomy – what body looks like
Physiology – how does the body function
Clade = a group that has a single shared ancestry → names for a group with characteristics they share (ex. Mammals, amniotes, tetrapod, vertebrates)
LESSON 5 - Dichotomous Keys
WHAT?
→ A tool identify different similar species when we see them
Di = 2 → always 2 options
How to make a good dichotomous key?
Use constant characteristics rather than ones that disappear or vary with the season (ex. A deer does not have antlers in winter)
Need to use characteristics that can be directly observable (ex. A penguin has a white belly, sharp beak, form mating pairs) → physical or behavioral
Use quantitative (number) measurements with an amount or dimension rather than vague terms (big/small)
How to monitor air?
Physical tests
Biological tests
Chemical tests
Lichens:
A collaboration of fungi and algae (fungi farming the algae)
They take all their water from the air → incredibly sensitive to air pollution
20,000 species (crustose, foliose, fruticose – beard)
LESSON 6 - 6 Kingdoms of Life
Eubacteria
Either heterotrophs or autotrophs (eat other things or makes things themselves)
Have a cell wall that is made of peptidoglycan
Simple organisms lacking nuclei
Photosynthesis
Archaebacteria
Live in extreme environment (volcano, zero oxygen, pool of arsenic)
Have a cell wall (not made of peptidoglycan)
Protists
Most are single celled, some are multi-celled (exp. kelp/algae
Some have a cell wall
Can be autotrophic, heterotrophic or both
Fungi
Multicellular
Eukaryotic
Heterotrophic
Reproduce sexually and asexually
Have a cell wall – Chitin (used for dissolving stitches)
Terrestrial
Plants
Multicellular
Eukaryotic
Autotrophic (exceptions include venus fly traps, pitcher plants – because don’t have enough Nitrogen in soil)
Reproduce sexually or asexually
Most are terrestrial, some aquatic
Photosynthesis
Animals
Multicellular
Eukaryotic
Most reproduce sexually
Heterotrophic
Live in terrestrial and aquatic habitats
Who am I Questions *** on test
Kingdom Animalia Key Features:
Organization → whether you have tissues (specialized cells to do something) or not
Classification = cell → tissue → organs → organ system → organism
Ex. sea sponge
Symmetry → two parts are the same when split
Radial symmetry = symmetrical all around
Bilateral symmetry = 2 sided symmetry on outside
Ex. jellyfish
Body Cavity → are you a tube within a tube
Acoelomate – have a tube but everything is attached
Pseudocoelomate – half and half
Coelomate – tube within a tube that are separate → humans can sit still while digesting
Segmentation → repeating body parts (genes that are copy pasted)
Ribs, limbs, spine
*** Taxonomy is not a law of nature
LESSON 7 - Microscopic Life
Eukaryotic = 10x bigger than bacteria, has DNA, has a nucleus
Why Care?
Bacteria affects the environment
Decomposers, food spoilage, cyanobacteria (oxygen), disease
Archaea are used for industry
DNA testing relies on enzymes that can survive at 70+ degrees celsius, diagnosing diseases, intestinal issues
Viruses
Prevention of disease, genetic engineering
Eubacteria | Archaea | |
General | Prokaryotes (no nucleus, 10x smaller than eukaryotic cells, 1 chromosome DNA, unicellular) | Prokaryotes (no nucleus, 10x smaller than eukaryotic cells, 1 chromosome DNA, unicellular) |
Shape | Spheres (Cocci), Rods (Bacilli), Spirals (Spirilla) | Spheres (Cocci), Rods (Bacilli), Spirals (Spirilla) |
Group | Many working together – some take on specialized tasks Ex. (Streptococci, Staphylococci, Diplococci) Diplo = 2 Strep = line Staph = clump | Diplo = 2 Strep = line Staph = clump |
Cell Wall | Have a cell wall made of protein and sugar combined
| Made of either protein or sugars
|
Nutrition |
|
|
Habitat | Mesophiles (moderate climates)
| Extremophiles (Live in extreme environments)
|
Reproduction | Asexually → copy DNA then split in half (Binary Fission) Sexually → Conjugation (plasmid/DNA exchange) – can pick up random pieces of DNA then copy it and share it with another Can shut down their cellular processes and create an Endospores (protective shell state) | Asexually → copy DNA then split in half (Binary Fission) Sexually → Conjugation (plasmid/DNA exchange) – can pick up random pieces of DNA then copy it and share it with another |
Other |
Earth formed 4.5 bya
First bacteria = 4.0 bya
Multicellular eukaryotes = 2.0 bya
Endosymbiosis Theory
2 prokaryotic cells – bigger one ate the smaller one
Did not digest it → little got protection and food and big one gets help for digestion & chemicals
After a while → it reproduces with both cells
“Inside working together”
That smaller one became the “mitochondria” of the cell
→ have 2 membranes (sucked in) and their own DNA
Formation of Eukaryotic cell
If eat another photosynthetic bacteria → plant cell
LESSON 8 - Viruses
Viral | Bacterial | |
Is it contagious | Yes | Sometimes |
Treated with antibiotics | No | Yes |
Examples | Common colds, flu, chicken pox | Strep, pneumonia, UTI |
Examples of Human Viruses:
Flu
Cold
Herpes or cold sores
Measles
What does it mean to be living?
Growth and development
Energy metabolism
Homeostasis
Adaptation as a species
Response to stimuli (things in external environment – movement and adaptation over a period of time)
Cells
Reproduction
Viruses…
Are: organized, evolve
Maybe: reproduction (only with a host), homeostasis, react to environment
Dont: grow and develop, metabolism
Classification:
What they look like (size and shape of capsid – protein coat surrounding RNA and DNA)
By type of disease
By who they affect (host)
Geometric
Virus Morphology
Extremely small!
17 nm - 400 nm in diameter
Smaller than light – need electron microscope
Viruses consist of:
DNA/RNA – code of just what the virus does
Surrounded by a membrane – in a protein coat (capsid)
Spikes = keys → spike has to match the receptors part of the host cell to get in (part that changes the most)
Optional: Envelope made of fat
Host Range:
The range of organisms a virus is capable of infecting
More concerning when viruses change their host range by mutations
All life forms have viruses
Virus Reproduction
Tells what kinds of disease they cause us (Lytic VS Lysogenic Cycle)
Lytic Cycle: (Destruction Cycle)
Phage attaches to the cell → spikes must match up with host
Phage DNA enters the cell
Hijacking = Host DNA now has a new instruction manual → host DNA breaks up
New virus cell forms
Lysis → new viruses break out of the cell
Can take hours to days (immediate)
Lysogenic Cycle: (Virus Hides)
Aka Retroviruses – Ex. Herpes, HIV
Worried because can only treat when go to Lytic Cycle
Attachment
Insert DNA
DNA merges and becomes part of the host DNA
When cells replicate → copy both virus and cell DNA
When stress (physical, mental, temperature) → causes virus to separate and begin Lytic Cycle
Not all viruses go into Lytic Cycle
Can take a long time
Viruses for Genetic Engineering
Take viruses → replace DNA and then reinsert them back into the body
Vaccines:
Some viruses mutate a lot, and some remain the same (vaccines works for this)
Immune cells on lookout for specific germs
Immune cells (WBC’s) arm and replicate → launching antibodies when detecting a virus
Leave behind memory cells specific for the attack of the full scale virus attack
Vaccine sends dead (destroyed to point of non-function) version of virus or parts of the virus – often just the spike
So memory cells are prepared if in contact with actual virus
COVID Vaccine:
Iserts RNA (information on how to create the spike) → prevents infection from getting bad
People who cannot get vaccinated:
Too old
Too young
Immunocompromised
Herd Immunity:
If only some people get vaccines → disease spreads rapidly
Goal → enough vaccinated (most of the population) people to separate people who are unvaccinated are less vulnerable
Protecting others
Will lessen the spread of disease / stop it
The more contagious the disease = the more % of population should be vaccinated to have herd immunity
Bio - Unit 2 Notes
Evolution
LESSON 1 - Intro
Evolution = the gradual change in traits of a population over time
Change at a population wide level
Very situational
Depends on 2 things:
Who survives to maturity
Who gets to reproduce
Evolution is a Theory → Explanation of a set of related observations or events based upon proven hypothesis and verified multiple times
Ex. Atomic theory, theory of relativity
Evolution Stories / VIST
Variation → we are not all identical
Inheritance → traits that are inheritable
Selection *
Time → generations
Evolution selects the best available answer (like multiple choice)
Example of VIST
The individuals of the species have many variations of the trait: A, B, C
This trait is heritable: Individuals with variation A will have babies w/ variation A
Colour is an inheritable trait
Individuals that had variation A were better able to survive and/or reproduce {selection}
Individuals with variation B were more likely to die young
Individuals with variation C lived, but found it harder to affect a mate
After several generations [time], most individuals of the species show variation A
Variation = any genetic differences amongst individuals in a population
May be structural, physiological, behavioral
Adaptation = a genetic difference that helps an organism survive and/or reproduce in a particular environment (can be advantages)
A variation that is useful for its environment
Ex. moths being peppered or black
Evolution is a natural process → but humans can interfere
Ex. Climate change, genetic engineering, artificial selection
Natural Selection:
Type of selection where you have to survive (predator and prey)
Type of selection where the better variations are the ones who continue to survive and not die off
3 Types of Natural Selection:
Directional Selection → where ONE extreme is favoured and the variation frequency continues to shift in one direction (ex. The moths)
Disruptive Selection → where BOTH extremes are favoured and they both continue to survive in different ways
Stabilizing Selection → where INTERMEDIATES are favoured and their variation continues to survive
Artificial Selection:
Type of selective pressure exerted by humans to “improve” desirable traits
Type of biotechnology
Pros:
Produce more food with same space
Con:
Less genetic diversity → risk of disease
Selective Pressure:
Any phenomena which alters the gene frequency (variation) of living organisms within a given environment
Antibiotic Resistance:
Bacteria mutates randomly → some can develop mutation that makes them antibiotic resistant (Variation)
Normally have enough good bacteria to prevent resistant bacteria from taking over
When using antibiotics → kill susceptible (non-resistant) bacteria but resistant bacteria survives (Selection)
When you don't take all the antibiotic pills the remaining bacteria multiples
The resistant bacteria now has lots of space to grow (Time)
Genetic engineering → able to pick the offspring, mess with Variation/Inheritance
Mimicry → type of camouflage – type of adaptation
If not camouflage, need to be good at hiding or have bigger problems of survival (are poisonous)
LESSON 2 - 5 Fingers of Evolution (Selection part of VIST):
Pinky → Genetic Drift (random chance) → The process of change in the variation of a population due to chance or random events
randomness can significantly affect what you have – smaller populations are more affected by random events
Founder effect → A few members of a large population leave to start a new population in somewhere new – the smaller the groups are the more effect this has on the population (ex. Ashkenazi Jews can have disorder called Tay Sachs)
Bottleneck effect → Random reduction in a population (from large population to small population – happening within the same place (ex. Natural disasters – In a population of 100 people with 3 colour blind people, there is a tsunami, and 75 people die. None of the colour blind people died)
Ring finger → Sexual Selection → The process whereby organisms with certain sex characteristics tend to reproduce more
pressure (physical, behavioural)
Ex. Male deer fight using their antlers to attract and keep mates
Middle finger → Mutation → The changing of the structure of a gene, resulting in a new variation
Ex. Some humans are born without wisdom teeth
Pointer finger → Gene Flow/Movement → The transfer or movement of genes/variation from one population to another
Ex. A group of Inuit from Nunavut move to Nova Scotia
Thumb → Natural Selection → The process whereby organisms better adapted to their environment tend to survive
Ex. Owls with good infrared vision are better able to see prey
LESSON 3 - Sexual Selection
Survival is not enough to pass through evolution → need a mate to reproduce and pass on your genes
Sexually selected traits:
Presents (food, sperm)
Try to look nice
Fighting for your mate
Generally the “try hard” in the relationship is males → because of the energy exertion (female to have offspring is a major energy investment)
The partner that invests less energy is the try hard
2 Categories:
Trying to assert dominance → Intrasexual selection (within one gender)
Women typically go for looks and men go for physical damage
Trying to attract → Intersexual selection (between genders)
Balance:
Optimal balance between natural and sexual selection
Ex. Peacock tails must be long to attract a mate but not too long to prevent them from flying away from prey
Disruptive selection = both extremes
Ex. short stalk eyed flies mate with each other and long stalk eyed flies mate with each other
Competing goals:
Males want as many mates
Females want the best mate
Ex. Males in water striders have evolved to have “rape arms”
- Females counter evolved ridges on their backs
Evolutionary arms race → constantly evolving with competing goals (happens for non-monogamous species)
Red Queen Hypothesis:
Males and females always evolving to one up each other (negative)
Idea that to maintain the current balance → you can’t stay the same in evolution
In order to maintain balance you have to keep evolving (just to stay the same)
Can apply to same species (sexual) or different species (prey)
Gender Dimorphism:
When males and females look extremely different → non-monogamous (ex. Mandarin ducks)
When monogamous → they typically look alike (ex. penguins)
Coevolution:
2 species evolving in response to each other
Any relationship between species (positive or negative)
Ex. Predator and prey, bees and flowers
LESSON 4 - Speciation
Speciation event happened when there is a split in a phylogenetic tree → something happened where the 2 groups are no longer reproducing
Speciation = the process by which groups evolve to become distinct species
Species = group of organisms consisting of similar individuals which can produce viable offspring
Can happen at 2 different speeds:
Gradualism = species that gradually/slowly get more different
Punctuated Equilibrium = when environment quickly changes there is a sudden big change – and then not changing after
Biological Species Concept: Reproductive Isolation
The two groups will not reproduce because they are 2 different species
Behavioural reproductive mechanism
Story of Speciation Event:
Step 1 → stop two groups from interacting – gene flow between 2 groups is disrupted
Step 2 → genetic mutations/variations accumulate – time makes these groups change
Step 3 → 2 groups are now reproductively isolated when together again
Allopatric Speciation → the 3 steps include a physical barrier (happens more often/easier)
Sympatric Speciation → the 3 steps include a preference/behaviour (non-physical) – long distances
Adaptive Radiation
If species goes somewhere new where nothing like it exists → lots of opportunities to succeed
One species (common ancestor) that can become many new species
Can be allopatric or sympatric
Relatively rapid
Ex. chains of islands (isolated, many habitats)
Reproductive Isolation Mechanisms:
How we know things are separate species
Divided into 2 groups:
Pre-zygotic → prevent from making a zygote (first cell with sperm and egg not coming together)
Habitat Isolation → if don’t live in the same spot, won’t mate (same geographic area yet separate or different habitat)
Temporal Isolation → reproductive cycles for mating occurs at different times (day vs night / seasonal)
Behavioural Isolation → distinct mating rituals not recognized by another species (what they like/dislike)
Differences in the behaviour prevent mating
Because there is no gene flow between populations, evolution occurs
Mechanical Isolation → structural differences in reproductive organs (the parts don’t fit)
Gametic Isolation → Gametes (sperm and egg) must be compatible (chemicals on both ends don’t match) – the sperm cannot fertilize eggs
Recognized each other by cell surface markers
Very important in aquatic species → broadcast spawners (they release sperm and egg into ocean hoping the waves will let them reproduce)
Ex. sea urchins (they have to match up or else will not fuse together)
Post-zygotic → prevent zygote/hybrid offspring from reproducing (sperm and egg come together but prevent from having baby)
Zygote Mortality → Initial cell formed upon fertilization dies
Genetics, mom cannot carry, chemically not compatible enough
Hybrid Inviability → have a baby, but the baby cannot live a full life (very weak, sickly, die early, cannot reproduce)
Ex. Leopard + Lion = Leopon (bad)
Hybrid Infertility → Offspring strong/fit and adults are healthy, yet are sterile (can’t reproduce)
Ex. Mules and Ligers
Hybrid Breakdown → First generation hybrids are viable and fertile BUT offspring in 2nd generation (when those hybrids try to reproduce) they are feeble or sterile
Mostly see this in plants
Plant Hybrids:
Humans have genetically made new plants, fruits
Ex. Lemon (Citron and bitter orange)
Experimental Results:
Dianne Dodd fed one group of fruit flies who evolved as she gave one set of fruit flies sugary foods and the other starchy foods
Examined the effects of geographic isolation and selection on fruit flies
The flies from the same group preferred to mate with each other
THEORISTS:
Cuvier = Catastrophism → Punctuated equilibrium
Lyell = Uniformitarianism → Gradualism
Lamarck = Inheriting acquired characteristics (whatever you try to become – that’s what you gain)
Darwin = Natural selection – all of things that were not strong died off
Both had idea of adaptation but HOW was different
LESSON 5 - Supporting Evidence
Fossils
Sign that things have not always been this way
Found in top layers of rock more closely resemble living species today – deeper is more different
Not all organisms appear at the same time/every layer
Appear in chronological order
Not easy to make → need to be buried very deep and very fast before decompose (so much pressure and heat) – atoms of their body get replaced by rock
Can make good predictions of lifestyles of fossils – Bones can tell how they moved, ate, what muscles → bumps and ridges can tell where muscles and tendons attaches
Can’t learn about soft tissue – if none preserved, hard to tell → can’t guarantee
Transitional fossils → can see every step of the journey
Ex. homosapien and homo neanderthals look very similar
Horses (used to be extremely small with 4 toes)
Archaeopteryx → some traits in modern birds (wings) and reptiles (tail vertebrae, beak, claws) – disruptive selection
Biogeography
Study of locations of organisms around the world which provides evidence of descent with modification (continental drift)
Species that look alike tend to live near each other
Continental Drift = why closely related species exist in different continents → dates back to Pangea continent
Anatomy
Vestigial Structures
A structure that is a reduced version of an ancestral structure
Ex. Whales have hip bones because their ancestors once had legs but not functional or useful anymore
Ex. human tail bones
Human pulmonary tendon (thumb and pinky, tilt wrist) → used to be useful for grip strength but useless now
Human wisdom teeth → used to wear away regular molars and needed new ones – but now is useless
Divergent Evolution/ Homologous Structures
When 2 things gradually get more different (diverge)
Species that had a recent common ancestor – used to be similar and then diverged
Occurs when populations changes as they adapt to different environmental conditions
Look alike on the INSIDE
Bone structure similar → 1 bone, 2 bones, a bunch of little bones, fingers
Same bone structure, different function
Evidence of recent common ancestor
Ex. human arm and whale arm
Convergent Evolution/ Analogous Structures
Even though started off as different species → similar traits arise because species have independently adapted to similar environmental conditions
Evolved for same for same reason but from different starting materials → same selection pressure, different origin
Not because share the same common ancestor
Ex. birds and bees both have wings, but no recent common ancestors
Look alike on OUTSIDE but structurally not the same
Different bone structure, same function
Evidence of similar environment
Ex. sharks (fish) and dolphins (mammal) but have fins, tails
Embryology
From zygote into a baby
Have tails, gills
Molecular Biology/ DNA
Makes change hard to track
Prefer to use mitochondrial DNA → have their own DNA and ONLY comes from MOM – perfect match
No negative consequence in mutation in this DNA
LESSON 6 - Altruism
Altruism = self-sacrifice for someone else
Success in group settings or family units
Kin Selection in Humans:
Family relationships matter
Ex. Person or Dog test → asked who would save (person – different levels of relatedness or dog) – the more closely related the humans, choose humans, the more distantly related, choose dog
Kin Selection Theory:
Self sacrifice depends on close family relationship because saving your DNA is saving my DNA – “secret selfishness”
Family shares DNA
Lose energy, food, life → want someone with same genetics as you
Most higher level species are more invested in family members
If family in danger → more likely to do things than for others in danger
Close family unit was more successful
Reciprocal Altruism Theory:
Unrelated organisms frequently cooperate → Cooperation/altruism depends on returning the favour
Does not rely on family
Giving favours to get a favour
Competition is not always the winning strategy – cooperation can win
Ex. Bird flight formation → Front bird takes air resistance off the others in the back – save energy
Ex. Fish schools make it harder for middle fish to get eaten
Ex. Primates groom non-relatives to make sure there are less parasites in group
Sometimes leads to a Red Queen scenario where one tries to cheat
What is required for Reciprocal Altruism:
Communication
Long-term memory
Able to recognize individuals (sensory)
Birds, fish, primates
Game Theory - Prisoner’s Dilemma:
How much do you trust the other person
If both cooperate → best outcome
If both defect
If only one defects → worse outcome
According to math → better to defect, but depends on number of rounds
When unknown number of rounds → better to cooperate
Cooperate from the beginning and then copy what the other person does = “tit for tat”
How does cooperation start?
Starts when there are 2 cooperators
Changes from always defecting to going for “tit for tat”
Bottleneck effect → kin selection in the small group, then cooperation spread if the population ever reunites with others
Selection for cooperation:
Some traits may be a problem for an individual, but but beneficial to the group – or vise versa
Individual success vs group success
Ex. Hawk dominates crow but many crows dominate hawk (group success)
Ex. Hens peck other hens for infertility (individual success)
Adaptations for Cooperation are sometimes more important than Survival Traits:
Sometimes adaptations that help us cooperate better are more important than even individual survival traits
Ex. humans needed communication so evolved to have pharynx and larynx next to esophagus (only epiglottis to stop from choking)
Bio - Unit 3 Notes
Genetics
Cell part | Function | Equivalent part of WCI |
Cell membrane | Regulates what goes into and out of the cell (liquids and solids) | Doors of school |
Mitochondria | Converts energy from food into energy a cell can use | Generators |
Nucleus | Contains genetic material (DNA) and controls the use of genes; found in eukaryotic cells | Principle |
Cytoplasm | Fluid that surrounds the organelles to hold them in place | Hallways |
ER | How the cell sends things around the cell and makes proteins (internal transport) | Legs for walking |
Vacuole | Storage units for water and sugar | Backpacks |
Centrioles | Perform mitosis (cell division) – only in animals | Classroom doors |
Lysosome | Taking old materials and making new things out of it | Trash can |
Cell Wall | For structural support in plants | Brick walls |
Chloroplast | Photosynthesis in plants | Cafeteria |
LESSON 1 - DNA
DNA = Deoxyribonucleic Acid
Information is in the rungs of ladder
When cells active → DNA has to be opened
But when want to move, change or make reproductive cells → DNA has to be coiled to not get broken
Changes that happens when broken = how bad the effect will be
Genetics = study of inheritance
Everything has the machinery to make and copy DNA
Genetic Material of Cells:
GENES – portions of DNA/units of genetic material that CODES FOR A SPECIFIC TRAIT
Each chromosome contains many genes
The number of genes does not tell you how complicated you are
DNA is made up of repeating molecules called NUCLEOTIDES (4 letters – ACTG)
Nucleotide = phosphate + sugar + nitrogen base (¼ chemicals – ACTG)
Different arrangements of nucleotides in DNA is the key to diversity in living organisms
The order of the letters in the DNA matters bc can code for something different
Rungs of ladder = bases
Outside = phosphate and sugars
Called double helix → there are 2 and attached the bases
Nitrogen Bases:
1. Adenine
2. Cytosine
3. Thymine
= pYrimidines (C & T have a Y in it)
4. Guanine
= Purines
Complementary Rule/ Chargaff’s Rule:
DNA has specific pairing between nitrogenous bases
Adenine + Thymine (straight sided letters)
Cytosine + Guanine (curved letters)
Their amounts in a given DNA molecule will be about the same
DNA Replication: Each strand of the original DNA serves as a template for the new strand
The DNA molecule unwinds, copies and then fills in the blanks → 2 identical new complementary strands following the complementary rule
Ex:
AT
CG
CG
TA
=
AT AT
CG CG
CG CG
TA TA
This is called Semiconservative DNA replication
Because the two strands are loosely connected by Hydrogen bonds
The “code” of the chromosome is the specific order that bases occur in.
DNA controls cell function by serving as instructions to make PROTEINS
Proteins perform almost every body function
CHALLENGE: Try using only four letters [T/A/S/R] to make as many words with different meanings as possible
DNA Structure:
Cannot be organized in a clump
Double helix wrapped around proteins which are wrapped up around each other
DNA is wrapped tightly around histones (proteins) and coiled tightly to form chromosomes → now can be read and travel
ANSWER
1. Why is DNA replication necessary?
Need new cells to grow/develop, reproduce, maintenance of body, repair of damage/injured cells
2. When does DNA replication occur?
Before mitosis occurs
3. Use the complementary rule to create the complementary DNA strand:
AGCTAGAGCAGT
TCGATCTCGTCA
Summarize the relationship between genes & DNA
Genes are a section of the DNA which code for a specific trait/protein
Describe the overall structure of the DNA molecule
Double helix – connected by
Ladder shape
Nucleotide = phosphate, sugar, nitrogenous base (ACTG)
4 kinds of bases
NAMING DNA
Chromatin = uncoiled DNA being used by cell → for transcription | Chromosome = bundled DNA (copied during interphase) → to transport |
Sister Chromatids = identical pieces of DNA bound by a centromere
| Homologous Chromosomes = NOT identical but code for the same traits
|
LESSON 2 - Mitosis
The cell cycle includes what 3 phases? What happens in each phase?
Interphase (pre-mitosis)
Before mitosis
The cell does normal cell activities (making cell proteins)
What the cell does majority of its life
DNA replication
Mitosis (only 4 stages during the cell division process)
Prophase
Metaphase
Anaphase
Telophase
Moving the DNA around
Cytokinesis (post cell division)
The splitting of the cells
What is DNA called when it is…
Uncoiled?
Chromatin
Coiled up?
Chromosome
An exact duplicate half of a chromosome?
Sister chromatids
How many different pieces of DNA do human cells have?
46 (23 from each parent)
Why do we need to make more cells (via mitosis)?
Mitosis produces new cells, and replaces old ones, or damaged cells
Developes growth in the body
What do we call the resulting new cells at the end of Mitosis?
2 daughter cells
What are the 4 phases of mitosis?
PHASE | Prophase | Metaphase | Anaphase | Telophase |
What Happens | The chromatin condenses into 2 chromosomes. Each chromosome has 2 halves called a sister chromatid. The 2 chromosomes move to either ends of the cell. The nucleus disintegrates. | Chromosomes line up in the middle of the cell | The sister chromatids pull apart and split up to opposite sides of the cell. | The 2 daughter cells start to split up (pinching membranes). Each newly forming cell makes a nucleus. Chromosomes uncoil to make chromatin. |
Picture |
What happens in Cytokinesis? What does the word Cytokinesis mean if you “English language translate it” (as Ms.W loves to say)?
Membranes of the cells divide completely → Cell Movement
After Mitosis and Cytokinesis: 2 genetically identical daughter cells have been produced.
LESSON 3 - Meiosis
= How we take body cells and turn them into gametes
Gametes don’t end up exactly the same (siblings)
Goal → increase variation
Sexual Reproduction = 2 parents reproduce → unique offspring
Chromosomes = bundles of DNA → every species dif number
Gametes must have half the humber if chromosomes as body cells
Diploid (2n) = the full amount of chromosomes (in a body cell) → theres 2 copies of each chromosome (1 mom, 1 dad)
46 in humans
Haploid (n) = the number of chromosomes in a gamete → half the normal amount
23 in humans
Meiosis
Built in mechanisms to share and change DNA to create more variation in offspring
Identical copies do not count as new genes
Only want half of DNA to be in our gametes
Result of the reduction to haploid is that there can be huge genetic variation within members
Law of independent assortment: random arrangement of homologous pairs → crossing over results in more variation
Gametes generation:
Energy difference starts early
Cytokinesis step differs
Nondisjunction: chromosomes/chromatin/chromatids do not separate properly and results in gametes with the wrong number of chromosomes → results in trisomy or monosomy
Could result from death to complications
Trisomy 21 → 3 copies of the 21st chromosome (down syndrome)
Monosomy → Missing one chromosome
Spermatogenesis
| Oogenesis
|
Chromosome Abnormalities:
Deletions: A portion of the chromosome is missing or deleted.
Frequently on chromosome 5
Duplications: A portion of the chromosome is duplicated = extra genetic material.
Inversions: A portion of the chromosome has broken off, turned upside down, and reattached = genetic material is inverted
Substitution: A portion of the chromosome has substitutes itself for a part of another chromosome
Translocations: A portion of one chromosome is transferred to another chromosome
LESSON 4 - Heredity
Initially → inheritance was regarded as paint mixing theory → mixing colours infinitely
However if that were to happen → we would all look identical
However idea that there is a smallest particle (trait) that mixes → mixing of multiple beads
Particulate Inheritance Theory:
Particles of inheritance = DNA
Specific variation of a gene (one trait) = Alleles
- Ex. gene = eye colour/ allele = brown
The combination of alleles that an individual has for a specific gene (Genetic instructions) = Genotype
- Ex. allele 1 = Brown (B), allele 2 = blue (b), Genotype = Bb
Observable characteristics (physical appearance) = Phenotype
- Ex. brown eyes, tall, brown hair
Genetics = the study of heredity → how traits are passed from parent to offspring
Different traits are inherited by different patterns of inheritance
Gregor Mendel (Aka father of genetics)
Monk and scientist
Had a garden → looked at traits of pea plants
He forced plants to breed (using paintbrush) how he wanted
Did this for years with thousands of plants
At the start “pure breeds” (P - parent generation) → tall plants with each other and small plants with each other
Then did this so that each of the variations were “pure breeds”
He then mixed tall (TT) and short plants (tt) which always produced tall plants (Tt) → Offspring called F1 (first filial generation)
Then bred F1 generation to make F2 generation (75% tall, 25% short – 3:1 ratio) → TT, Tt, Tt, tt
Question: how did short plants reappear in F2 generation → discovered 2 rules
LAW OF SEGREGATION:
Came up with idea of homologous chromosomes and meiosis
Each tall plant from the F1 generation carried 2 ALLELES (2 copies of the trait)
DOMINANT TRAITS RULE:
Strong traits covered weak traits
Stronger/ always expressed = Dominant (T)
Weaker/ only when dominant not expressed = recessive (t)
2 copies but only pass on one trait:
1 tall allele → Dominant
1 short allele → Recessive
Heterozygous → if 2 alleles for a trait are different (Aa)
Homozygous → if 2 alleles for a trait are the same
AA = homozygous dominant
aa = homozygous recessive
PUNNETT SQUARES:
Not guaranteed
Every time have a kid, results can vary (because people don’t have that many kids)
Parent #1 had to be heterozygous if child has no widow’s peak
EX. #2: Tongue rolling
Genotypic Ratio:
RR = ¼
Rr = 2/4 or ½
rr = ¼
Phenotypic Ratio:
Rollers = ¾
Nonrollers = ¼
DIHYBRID CROSSES:
2 punnett squares for 2 traits at a time (2 separate chromosomes)
If heterozygous for both traits → 9:3:3:1 phenotypic ratio
Ex. Ffdd x FfDd
Freckles = dom
Dimples = dom
Freckles Dimples
What are the odds of both?
¾ x ½ = ⅜
What are the odds of neither?
¼ x ½ = ⅛
What are the odds of freckles and no dimples?
¾ x ½ = ⅜
LESSON 5 - More Complex Patterns of Inheritance
→ Most traits are not simply dominant / recessive
Incomplete Dominance = neither allele is completely dominant over other → Heterozygous (a third new) phenotype is created = middle ground
Ex. Pink flowers from red and white
Codominance = BOTH alleles are equally dominant and expressed
Ex. Roan cows = red and white patches
Ex. in humans → sickle cell anemia
Protein hemoglobin gets built wrong (straight line) causing cell to become sharp and pointy → causes blood clots easily and not great at carrying oxygen
However very difficult for malaria to attach to sickle cells → common in people with recent African ancestry
Heterozygous (HbA HbS) = sickle cell trait → best of both worlds for people in malaria environment
LESSON 6 - Multiple Alleles
More than 2 alleles possible for a given trait/gene
Allows larger amounts of variation – both genotypic and phenotypic
Although more alleles → can only inherit 2 at a time
There is an order of dominance
Ex. Blood type = 4 blood types in 3 alleles
Always on lookout for antibodies that are not you → will clot
Antigens = you
Antibodies = Immune system trying to fight things that are not you
IA = A antigen on RBC (IAIA , IAi)
IB = B antigen on RBC (IBIB, IBi)
i/ O = neither A or B antigen (ii)
AB = both A and B antigen (IAIB)
Phenotype | Possible Genotypes | Allele (antigen) on RBC surface | Can donate blood to | Can receive blood from |
A | IAi IAIA | A | A, AB | A, O |
B | IBi IBIB | B | B, AB | B, O |
AB | IAIB | AB | AB | A, B, AB, O |
O | ii | O | A, B, AB, O | O |
AB = universal recipient → everything is them
O = universal donor → but can only receive from themselves
Rh Factor
Inherited antigen (protein) on the surface of RBC
+ blood type = have Rh protein (more common)
– blood type = don’t have Rh protein
Tells you what antibodies your body makes (Rh - [2 - alleles] is against Rh +)
Important → indicates whether blood of 2 different people is compatible when mixed
Examples:
Baby
If mom and baby blood type don’t match up, then mom can create anti-D antibodies which can lead to the baby having Rhesus disease
Issue when woman is - and baby is +
Can cause misscarriage
Blood transfusions
→ Rh + can receive from Rh + and Rh –
→ Rh – can only receive Rh – (because makes anti-Rh antibodies)
Testing Blood Type:
Take antibodies from blood and test different antibodies
Blood Coagulation → Reaction will happen if it reacts to anti-itself
Ex. If blood type A (with B antibodies) interacts with B blood – then B antibodies will clot the B blood
Reacts with anti-A antibody | Reacts with anti-B antibody | Blood type |
Yes | Yes | AB |
Yes | No | A |
No | Yes | B |
No | No | O |
LESSON 7: Polygenic Traits
Polygenic Traits = Expression of a trait by several genes → shows continuous variation
Ex. eye colour, height, skin colour
Multifactorial Traits = control of expression of a trait by several genes and environmental factors → shows continuous variation
Ex. skin colour → genetics and sunlight
Ex. human height → genetics and nutrients fed as a child
How to see what is genetic/environmental?
→ Identical twins – if have only the same some of the time, then it is most likely an environmental trait
LESSON 8 - Epistasis & Linked Genes
Epistasis
One gene depends on another gene for it to be expressed → controls whether you even see the results of the other gene
Ex. Llama – gene for wool colour and gene for expression of colour
Linked Genes
Discovered by Thomas Hunt Morgan → expected Mendel’s ratio (9:3:3:1 – independent assortment) when breeding fruit flies (eye colour and gender)
The traits that he happened to have picked were linked → physically on the same chromosome
More looked at sex-linked traits
Linked Gene = physically sit close together on a chromosome, making them likely to be inherited together
Further apart → crossing over more likely to separate them
Sex-Linked Traits
Gene is attached to the X chromosome only, not Y (or vise versa)
More commonly expressed in males
Carrier = heterozygous
Punnett Square → X chromosomes first, dominant trait first
Phenotype ratio – separate by gender
Ex. red-green colour blindness = X-linked, recessive
Colour blind man x woman carrier
Normal vision man x woman carrier
Daughter = 50% odds of being carrier but no colour blindness
Son = 25% regular, 25% colour blind
Too Many X’s
Women have 2 X chromosomes but only needs one to survive
Some cells use one X chromosome and some in the body use the other – the one not used gets “turned off” / bundled
LESSON 9 - Pedigrees
Tracking disease/traits through families’ phenotypes to find inheritance patterns
Dominant = shows up in EVERY generation – never skips
Recessive = skips generations – parent(s) are heterozygous
Autosomal = not on sex chromosome
Sex-linked = on sex chromosome
Y-linked → only males carry trait
X-linked recessive → mostly sons inherit from normal parents
X-linked dominant → sons and daughters inherit from affected parents
Questions:
Difference between a Punnett square and a Pedigree
Punnett = predicting offspring
Pedigree = looking at family traits, pattern of inheritance
Can doctors predict who will get a particular disease based on a genotype for one gene alone?
If the gene is dependent on one gene then yes (ex. Hemophilia, Tay Sachs)
If the gene is multifactorial (multiple genes and environmental factors) then not really – can say risk level
(ex. Diabetes, heart disease) → by controlling environmental factors, you can adjust your risk
Why might factors, such as food choices, pollution, smoking not have the same effect on all people?
Answer in Q2
What are some advantages and disadvantages of genetic testing?
Advantages: proactive things you can do when finding genetic disease to prevent serious effects
Disadvantages: life is sometimes “easier” if you don’t know (ex. Carrier parents of tay sachs need to decide if they want to risk having kids)
Bio - Unit 4 Notes
Body Systems
LESSON 1: Nutrients
DIGESTION: "The process of conversion of complex food particles into simplest forms by the action of Enzymes"
What is a Macromolecule?
= Large molecules (hundreds-thousands of atoms)
Living things are made of macromolecules – food is made of living things
4 main types of macromolecules:
Carbohydrates
Lipids
Proteins
Nucleic acids (DNA / RNA)
Different digestive tools/ mechanisms to break down different foods
Fill in the table below on different types of Macromolecules?
Macromolecule | Made of | Functions | Examples |
Carbohydrates |
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Lipids |
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Proteins |
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Nucleic Acids |
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Are natural sources of sugar (like honey) healthier to consume than artificial sources (like HFCS)?
No because they have other fake sugars such as corn syrup which are just as bad or worse
What are Trans Fats? Why are they now banned in Canada?
Processed foods → causes atherosclerosis
What are Vitamins and Minerals?
Micromolecules → elements (Ca, P, K, S, Mg, Cl, Na) and trace elements (Fe, I, Mn, Cu, Zn)
Responsible for supporting body processes
Ex. B12 helps with Iron absorption
Eat a balanced diet
2 Types:
Water-soluble → pee out extra (lose often)
Fat-soluble → stored in the fat in your body (lose rarely)
Can you overdose on Vitamins and Minerals?
Can help to take if deficient
Too much fat-soluble vitamins can be stored in your body and can overdose
Diet can also affect overdose (ex. Too much sodium = heart disease, stroke)
Why is digestion different in Autotrophs vs. Heterotrophs?
Heterotrophs need to get their food
Autotrophs make their own food
What are the steps of Digestion? (Name and description)
Ingestion → food in body (surrounded by body)
Plants make their own food → Photosynthesis
Heterotrophs/animals obtain food
Digestion → break down into small pieces
Mechanical or chemical digestion
Absorption → get nutrients and energy into cells (in body tissues – crossing cell membranes)
Transport of digested nutrients into tissues (usually via the circulatory system)
Egestion → waste products removed/ exit body
What are 3 different styles of Ingestion?
Filter feeding (water creatures) → engulf large bodies of water and strains out water and keeps food (ex. whales)
Fluid feeding → feeding off fluid from prey (ex. Mosquitoes drink blood from humans)
Gathering and feeding (ex. Mouths of cow, hands of human, elephant trunk)
What is mechanical digestion? Chemical digestion? How does chemical digestion occur?
Digestion = the obtained food must be broken down into more simple form
Mechanical digestion = physical breakdown of food (grinding, crushing, tearing, ripping)
Chemical digestion = Using chemicals/enzymes to break down chemical bonds in foods
2 types of products made:
Digested foods (simple nutrients)
Unnecessary waste products
Why are enzymes useful?
Are proteins that regulate the rate of chemical reactions (biological versions of catalysts)
Speed up chemical reactions
Do not get used up – can be used over again
Specific enzymes for each nutrient
What we eat depends on what enzymes we have (lock and key analogy)
Describe digestion in Amoeba.
Single-celled organism
Ingestion → no mouth, extend cell membrane (pseudopods) around food where ends fuse – to form a food vacuole
Digestion → Throws enzymes at food with lysosomes
Egestion → temporary opening for food to exit
Describe digestion in Hydra.
Ingestion → Poisonous tentacles shoves food in hole
Digestion → Tube contracts – mechanical breakdown
Absorption → Absorbed into cells – chemical breakdown
Egestion → back out the mouth
Describe digestion in Earthworms.
Complex digestion:
2 holes (one-way system)
In specialized organs, not in every cell
What seems to be the qualifiers to count as Simple vs Complex Digestion?
Simple digestion:
One hole
In every cell in the body
Complex digestion:
2 holes (one-way system)
In specialized organs, not in every cell
What is the major difference in the digestive systems of herbivores vs. carnivores? Why?
Carnivores = much shorter digestive system
Herbivores = longer large intestine since they have to digest cellulose (more time to break down) → specifically the caecum is enlarged since it has enzymes to break down cellulose
LESSON 2: Human Digestive System
ORGAN | STRUCTURE | FUNCTION | ENZYMES AND OTHER SUBSTANCES | |
Mouth | Tongue, Teeth (diff types for diff purposes), Incisors, Canines, Molars Salivary Glands Mechanical: Adult Teeth (32) Wisdom teeth (part of the 32) come in during high school, sometimes removed | Ingestion Teeth: Mechanically mash up food Saliva: Mucous = moisten food so it doesn’t damage your esophagus Enzyme amylase I = chemically digest carbs | Amylase I digests starch into glucose Mucous (not an enzyme) | |
Esophagus | Smooth involuntary muscle tube | Swallowing → smooth involuntary muscles contract in sequence – Peristalsis | ||
Stomach | Bag of multiple layers of muscle Lower Esophageal (cardiac) Sphincter = circular muscle that contracts (connecting esophagus to stomach) to ensure food travels one-way Pyloric Sphincter = stays firmly shut until stomach has chance to do its job | Storage → inflate and expand Mechanical digestion → Peristalsis Chemical digestion → break down proteins | Mucous lining = protecting against HCl Parietal Cell = HCl (starts to break proteins, kill bad bacteria, activate pepsinogen enzyme) Chief cells = Pepsinogen (not functional when made – only usable to break down protein once activated) HCl + Pepsinogen = Pepsin → break down protein | |
Small Intestine (30 ft) | Duodenum | Duodenum: short Jejunum & Ileum: 6-7 m long → folded Lined with epithelial tissue which have villi (big folds) and microvilli (microscopic folds on folds) Villi contain many blood vessels (capillaries) Villi are to increase surface area | Finish digesting the chyme from stomach, Calls on pancreas using hormone prosecretin (doesn’t work until in contact with HCl), then turns into secretin which gives signal for pancreas to send its chemicals | |
Jejunum | Absorption: Blood supply accepts sugars and amino acids. Lacteals (lymphatic system) accept fatty acids → which will eventually be absorbed into bloodstream | |||
Ileum | taking in nutrients Vitamin absorption | |||
Accessory Organs | Pancreas | Sends: bicarbonate (base) to neutralize HCl Enzymes: Amylase II (carbs) Erepsin (proteins) Lipase (fats) | ||
Liver | Produces bile (mechanical digestion of fat) → breaks it into fatty acids, filters blood supply | |||
Gallbladder | Storage of extra bile | |||
Large Intestine | Caecum + Appendix (accessory organ) | Wider in diameter and does not need as much surface area for absorption | Store good bacteria to help digest more → extra bacteria is stored in the appendix | |
Colon | Most water absorption (suck water out of poop)
| |||
Rectum |
Other Important Terms to Watch For:
Technical Term | What is it? |
Bolus | Food + Saliva |
Peristalsis | Smooth involuntary muscles contract in sequence |
Sphincter | Circular muscle that contracts to ensure food is pushed one way |
Chyme | Food + Saliva + HCl + Enzymes |
Lymph Nodes = store immune cells
Fluid has to run back through lymph nodes before leaked fluid in the Lymphatic system can come back into the body. If there is swelling → infection.
Fats are absorbed into the lymphatic system which will then go to the bloodstream
List All Steps of Digestion in Order (mechanical and chemical – including specific enzymes and organs) (don’t forget absorption and excretion of wastes) | ||
Breakdown of Carbs | Breakdown of Lipids (fats) | Breakdown of Proteins |
Label the Organs of the Digestive System
Label the Organs of the Digestive System Left Side (Match the diagram above) Right Side | |
LESSON 3: Probiotics (Microbiome)
Aka bacteria that already lives inside of you
Can survive stomach acid
What it does?
Out compete / keep away bad bacteria
Digest food
Modulate (adjust) immune system → creates a balance
Only want immune system to respond when necessary
Helps the immune system not respond to harmless stimuli (ex. Allergies)
Want to take probiotics when microbiome is disrupted
LESSON 4: Drugs & Digestion
The molecule / medicine is just the start
Need to understand how it will flow through the body
Methods → pills through mouth (swallowed or dissolved), injections, inhaled, skin absorption, suppositories through butt
If want to work quickly → want to be dissolved ealy in digestion
Need to shield drug from stomach acid, but then dissolve in the mild intestines
Many other factors affect how drugs will affect the body
Also, if you are physically fit → faster peristalsis for drugs to have a faster effect
Ex. Aspirin → blood thinner in order to prevent from blood clots
Has enzyme → COX-1 which blocks making mucous lining – can lead to ulcers and bleeding
Therefore if has the coating → the top coating will withstand the acidity of stomach and then the bottom coating is a base that will dissolve in the intestines
LESSON 5 - Respiratory System
KEY TERMS:
Respiration → all processes required to bring O2 into body cells (and release CO2)
Involves rib cage, diaphragm, nose, mouth, etc.
2 Requirements:
A large respiratory surface/membrane
Needs to be large because need enough O2
Surface area has to be moist → water has to dissolve CO2 and O2
Ex. Frogs are moist on their skin where they breathe
Ventilation → getting O2 across a respiratory surface (that does gas exchange)
Gas Exchange → the transfer of CO2 and O2 across cellular membranes
CO2 is constantly being made as a waste product of ATP → Need to get rid of it
Happens via diffusion since particles are so small
Nature always wants a balance of particles between membranes
Goes from high concentration from outside body and enters the low concentration in the cells → eventually reaches equilibrium
Respiratory Surface on Outside VS Inside:
Membrane on Inside | Membrane on Outside | |
Pros |
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Cons |
Need systems to:
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Examples | Humans, insects, rabbits, birds, fish |
Axolotl, frog |
Inside Respiratory System (Human):
There is space where gas exchange is not occurring
No breathing/ gas exchange happening on exhale
Different types of breathing:
Number of respiratory surfaces:
Humans have 1 respiratory surface → alveoli
Frogs have 3 respiratory surfaces → through their skin, lungs, mouth
Insects breathe through a series of holes (spiracles) along their body attached to tubes
Type of breathing:
Tidal breathing → gas exchange only on inhale – ex. humans
Unidirectional breathing → gas exchange twice on every breath – ex. Birds (allows them to fly due to the large energy expenditure)
Tidal and Unidirectional → Fish breathe through water → gill cover opens and water comes out operculular (holes)
Efficiency of gas exchange:
Will never extract all/most of O2 from air → only half can get in through diffusion (equilibrium)
Most animals & humans = Concurrent flow → water and blood continue to diffuse until equal (random directions) – blood flow and water flow goes in one direction, water will lose O2 and blood will gain, limits them to 50% of O2 exchange
Fish = Countercurrent flow → Blood vessels go one way, gills go the other way – allows them to maximize gas exchange
allows gills of fish to pick up most of O2 in water (90%)
Human Respiratory System:
Nasal cavity → have ridges (sinuses) to make the air swirl to filter, warm up and get moisture before reaching lungs – sinus cavities (spaces) fill up with mucous (can cause sinus infections when it does not drain properly)
Pharynx → connects nose and mouth cavity
Epiglottis (flap of skin at the end of pharynx) → closes when swallow to cover the trachea – when it misses, you will choke
Larynx → vocal chords – pieces of tissue that have muscles to shorten (high) and lengthen (low) them to change the pitch
Trachea → respiratory
Esophagus (behind trachea) → digestive system
Bronchi → moves air to gas exchange surface (lungs)
Bronchioles → smaller branches to get to alveoli
Alveoli → 1 cell thick, dead-end sacs surrounded by blood vessels for gas exchange
Diaphragm → underneath
GAS EXCHANGE
Both lungs have capillaries surrounding alveoli
Capillaries are never more than one cell away from each other
Exhale more H2O and CO2 than inhale, but also exhale O2
2 Types:
External Gas Exchange between lungs ←→ blood vessels
(O2 →) (← CO2)
Internal Gas Exchange between blood vessels ←→ body cells
(O2 →) (← CO2)
Transport in Blood:
Oxygen Transport:
Mostly carried by Hb in RBC’s
Dissolves in blood – O2 (aq)
CO2 Transport:
Dissolves in blood – CO2 (aq)
Attaches to Hb in RBC’s
Carried by bicarbonate in blood – CO2 + H2O ←→ Carbonic Acid (H2CO3) ←→ HCO3- + H+
As more CO2 is taken up by the blood, the blood increases in acidity = causing BR to increase
Blood too acidic or too basic → die
Blood Ph needs to exist between 7.2-7.4
BR will continue to increase and decrease based on controlling acidity in the blood
Mechanics of Breathing:
Have to create enough empty space in chest → air will rush in to fill that space
Muscles along diaphragm and in between ribs (intercostal muscles)
Inhale (Inspiration):
Ribs move up and out
Diaphragm contracts down
Increased the volume of chest cavity → creating low pressure → air rushes in to fill the void in lungs
Takes more energy since contracting muscles
Exhale (Expiration):
Ribs go down
Diaphragm goes up
Decreasing volume of chest cavity → higher pressure → air gets pushed out of lungs
Takes less energy since relaxing muscles
Pressure and volume have an inverse relationship – when up the other down (vise versa)
Controlling Breathing:
Oxygen sensor → Aorta – constantly checking on breathing rate
If BR is too low, sends a message to brain which sends to diaphragm and intercostal muscles to contract
Medulla (brainstem) sensor → having a sensor that constantly checking blood Ph (CO2 sensor) and most important structure in entire body
Carotid body → Carotid Artery – body sensor (O2 and CO2 sensor)
Tracking Breathing:
Speromater → tracks inspiration and expiration in breathing
Tidal Volume (TV) → Normal inhale and exhale
Functional Vital Capacity (FVC) → the maximum amount of air inhaled and exhaled
Residual Lung Volume (RLV) → You can never exhale all the O2 out of lungs – Lungs will stick to themselves if all the O2 is exhaled out of their lungs
Respiratory Disorders:
Restricted breathing → a hard time fully expanding your lungs (something wrong with chest cavity, can occur when tissue in chest wall becomes stiffened or due to weakened muscles or damaged nerves)
Obstructive breathing → narrowing of airways hinder a person’s ability to expel air (something wrong with tubes – makes activity harder)
Examples:
Asthma → airway tube gets smaller and muscle surrounding bronchioles constricts
COPD → bronchitis (mucous build up in the walls) and emphysema together
Emphysema → walls of alveoli break – not much surface area and gas exchange
Smoking:
Healthy lungs = pink
Tar filled lungs = black
Smoking breaks down alveoli walls → COPD, Emphysema
However does not feel like can’t breathe as well as nicotine allows your alveoli walls to open
Can recover from damage eventually
Vaping:
No tar in it
Was meant to be a transitional device for cigarette smokers
Has all the same effects as smoking, just less
Long term → can lead to emphysema or COPD
Heart → increased atherosclerosis, BP, HR
Air Pollution:
PM – smaller the particulate matter, the deeper it can get into the lungs
Ex. methane, carbon monoxide, fossil fuels, nitrogen oxide
Respiratory problems → asthma
Children → still developing (lungs are growing/ changing), BR 2x as much as adults (bc need more O2 and smaller lungs)
High Altitude Breathing:
Big strain on respiratory and circulatory systems
At ground level there is a larger amount of O2, but as you go higher, less O2 available → due to gravity
When less O2 in higher altitude → BR & HR increases (hyperventilating), sleep less, urinate more
Blood becomes thicker, body starts making more RBC’s after a few days → acclimatization (body adjusting to the climate)
Altitude training:
Train where you get the benefits of more RBC and arrive at the event the day before
Blood doping → taking out blood at high altitude and give yourself blood transfusion before your events
Pros:
More RBCs
Enhanced O2 transport
Increased endurance
Cons:
Dehydration
Stress
Lack of iron
Carbon Monoxide Poisoning:
Hb loves CO
RBCs will preferentially pick up CO, even if O2 is available
“Silent Killer”
CO is invisible to sense and about the same density of air
fatigue, H/A, nausea – no alarming symptoms other than dizziness and chest tightness
CO is a result of incomplete combustion → found in furnace in house
CO detectors / alarms are a law to have in houses since 2014 – changes to a new chemical that sets off an alarm
Circulatory System:
Main functions:
Transport
O2/CO2
Components of the immune system
Wastes
Hormones
Components needed for repair
Transports everything
Helps to regulate body temperature as well
Single Celled Organisms:
No specialized/true circulatory system
Undergoes cytoplasmic streaming - circulates fluid within the cell
Equivalent of using a squeeze bottle
3 parts of circulatory systems in multicellular organisms:
Fluids,
Tubes and vessels
Pump
Different types of circulatory systems:
Open - fluid pumped out of tubes into body cavity, tubes are open to the body cavity
A few tubes connected to the pump and then blood flows freely throughout the body eventually reaching the tubes again
Low energy and efficient, but have to be small (insects)
Closed - closed complete circuit of blood vessels - blood always gets where it needs to go
Much more efficient at getting stuff where it needs to go, far harder to set up, need to build way more blood vessels, if one pops it must be repaired
Blood stays in blood vessels
Tubes connected to pumps - no breaks
Very efficient but need lots of blood vessels (high energy)
Open System - 90% of animals
Circuit of vessels is incomplete
Not efficient enough to support a large animal, but is in all insects
Most typical animals are all closed, but that is a very small percentage of all animals
Fluids (not blood) pour from vessels into body cavity and back
Eventually goes back to heart and gets recirculated but not very efficient
Benefit: doesn’t require a lot of building material or repair, less effort in construction and repair of blood vessels, less energy to create and maintain
Pumping action returns fluids to the heart
No oxygen carrying molecules
Works good enough for insects
Closed system
Circulatory vessels make a complete circuit
Fluids stay in the vessels where they are supposed to be, always get where they need to be
Circulatory Structures (Blood Vessels):
Heart
Have chambers → collecting blood (atrium) & pumping blood (ventricle)
Elastic Artery (high pressure)
smaller internal diameter
thicker muscular walls
Carries O2 blood from heart to body
Arterioles (smaller tube)
Capillaries (walls = 1 cell thick) → gas exchange
Surround every cell in the body
Venules
Veins (low pressure) →
wider internal diameter
thinner walls
Have one-way valves – prevent backflow
Carries d-O2 blood back to heart
Back into heart
With every beat of the heart → the valves pushes the blood through the veins
Varicose Veins → Blood pools within the valves and is not properly pushed through the valves (can see bulges on outside – typically lower leg)
Can cause blood clots → DVT
To fix it → compression socks, heat (catheter), inject to collapse veins
Spider Veins → not harmful, purple in colour, veins ripped slightly
Blood Composition:
½ Plasma → water, ions, nutrients, gases, wastes (anything dissolved in liquid)
½ Solids → Mostly RBCs – carry O2 and CO2
Have no nucleus, time limited → will live as long as possible and then get recycled because there are no instructions to make more (no mitosis)
Made in bone marrow
→ WBCs (Immune system & large) and Platelets (clotting & tiny – acts like webs)
Also made in the bone marrow
Heart Comparative Anatomy:
Fish → 1 atrium, 1 ventricle – d-O2 blood go to capillaries, picks up O2 (becomes O2 blood), delivers it to the body, then returns d-O2 blood back to atrium
Frog → 2 atriums, 1 ventricle
D-O2 enters 1 atrium, goes to ventricle, goes to lungs (gas exchange), O2 blood back to ventricle, pumped to rest of body
Errors: d-O2 and O2 blood mix in the ventricle
d-O2 blood can get sent back to body
O2 blood can get sent back to lungs
Human Circulation:
Pulmonary Circuit = heart ←→ lungs
Systemic Circuit = heart ←→ body
Cardiac Circuit = heart ←→ heart muscle
Heart attack occurs in this circulation
LESSON 2 - The Human Heart Anatomy:
Made of cardiac muscle
Valves open and close with the beating of the heart
Right side → d-O2 blood sent to lungs
Right ventricle thin muscle wall compared to left
Left side → O2 blood sent to body
Right Side:
Start by collecting d-O2 blood from superior and inferior vena cava
Then empties in the right atrium (collecting chamber)
Tricuspid (3 flaps) valve (ensure one-way)
Blood goes to right ventricle (pumping chamber) which contracts
Pulmonary semilunar valve
Pulmonary arteries to lungs to get O2
Left Side:
O2 blood comes back to heart by pulmonary veins
Blood empties into left atrium
Goes through mitral / bicuspid valve (2 flaps)
Left ventricle → thick muscular wall that pumps the oxygenated blood to your entire body
Aortic semilunar valve
Blood now moves through Aorta → biggest, highest pressure artery in the body, giant curved blood vessel
Pumps upward to neck and head, rest follows the curve down and runs down the spine and into the abdomen and then both legs through abdominal aorta
Instant death if this breaks
Heart Beat:
Closing of the valves creates heartbeat noise (aortic and pulmonary closing together, tricuspid and bicuspid closing together) - 2 beat noises
“Lub-Dub” = word for heartbeat sound
Atriums refill ventricles, pause, ventricles refire
2 sounds, 4 valves → 2 will always close at the same time
Heart murmur = what docs listen for when listening to valves
Listening for a whoosh sound
Means valve is stiff or leaking
LESSON 3 - The Electrical System:
Heart runs independently since it has its own electrical NS with 4 parts
Sinoatrial (SA) node
Specialized cells that generate electricity and sends signal to atriums to contract
Pacemaker → decides on pace of heart pumping – send signal to both atriums independently from brain
Also sends signal to AV nodes
Atrioventricular (AV) node
Connecting atrium to ventricle
Recieves SA signal but waits → has a time delay for everything not to contract at once
Sends signal down septum (Bundle of HIS - nerve fibres) of heart, separates at the bottom of both ventricles (purkinje fibres) and tells ventricles to contract bottom up
Bundle of HIS
Purkinje Fibres
Ensure ventricles contract from bottom up
ECG - Electrocardiogram:
1 heart beat
P wave → SA node signal (little bump)
Atriums contract
Q wave → (little dip)
R wave → atriums relax (large bump)
S wave → (little bump)
QRS = AV node signal
Ventricles contract
T wave → reset heart electrical system –put + and - ions back where they started– and ventricles relax
Reading ECG:
Vertical boxes = electricity
Each box = 1 mV
Horizontal boxes = time
Each box = 0.04 sec
Things that go wrong:
Fast heartbeat = as ventricles relaxing, atriums are already contracting → T and P wave overlapping
Slow heartbeat = interval between heartbeats is longer
Irregular heartbeat = inconsistent intervals (fast and slow combined)
Examples:
Tachycardia → fast heartbeat
Myocardial infarction → Ventricles not contracting – S wave not working
Extrasystole → premature / extra heart beat
Ventricular fibrillation → heart barely contracting – needs to be restarted
Complete heart block → SA and AV nodes not communicating / working together
Pacemaker = when SA node does not work properly
LESSON 4 - Blood Pressure
Monitors circulation → the pressure at which blood pushes on the blood vessels
Excellent determinant of cardiovascular health
Regular BP = 120/80 or 115/75 mmHg systolic
High BP can cause: heart attack, stroke, H/A, elevated BS, eye problems, kidney failure
Systolic Pressure:
Top number of BP → should be around 115 mm
Ventricles contract → blood getting pushed through arteries
Diastolic Pressure:
Bottom number BP → should be around 75 mm
Ventricles relax → atriums contract
How to take BP:
Put sphygmomanometer around brachial artery (around underneath armpit)
Find pulse around elbow area
Take the stethoscope and place the ears facing forward
Inflate until around 140 → past systolic
Release the knob slightly and put stethoscope on elbow
Artery goes from open (heart pushes blood) to compressed shut in high pressure → every time heart beats force opens, relaxes – cuff forces it shut making thud sound
Stop hearing sound during diastolic because artery will not shut
14 x 6 = 84 bpm → normal = 60-80 bpm at rest
17 → right after standing up
16 → standing
Baroreceptor Reflex:
In aorta, baroreceptor detects drop in pressure (measuring BP) → signals sent to the medulla → tells SA node to work
When standing up immediately BP drops, but body panics and momentary spikes BP and pulse (reflex), then drops back to normal (to not pass out)
Cardiac Output:
= Blood out of heart / min
Need to know:
Heart rate (bpm) x stroke volume (mL/beat) → how much fluid moving per beat
Stroke volume avg = 70 mL
Heart rate avg = 60-80 bpm
70 beats/min x 70 mL/beat = 4900 mL/min (4.9 L / min)
When exercising → can increase heart rate by 7x (35 L / min)
Factors affecting HR:
Hormones
Fitness levels
Age
Genetics
Factors affecting SV:
Heart size
Gender
Fitness
Genetics
Examples:
Person A = 70 bpm, 70 SV, CO = 4900 mL → normal
Person B = 85 bpm, 35 SV, CO = 3000 mL → in trouble / hospital
Person C = 40 bpm, 125 SV, CO = 5000 mL → athlete
Person D = 80 bpm, 62 SV, CO = 5000 mL → couch potato
Person E = 200 bpm, 150 SV, CO = 30,000 mL → exercising now
Cardiovascular System Diseases:
Vessels:
| Heart:
|
Blood:
| Electrical:
|
Bio - Unit 1 Notes
Biodiversity
LESSON 1 - Intro to Diversity
Ecosystem biodiversity – different types of habitats, communities and ecological processes (ex. tropical deserts, alpines, tundra, ocean)
There are microhabitats within an ecosystem which sustain different purposes (ex. Forest has several layers which the environment fosters different living things)
Species biodiversity – how many species do we have → taking number of known species and number of new species, estimated to be around 100 million species
Genetic biodiversity – within one species (ex. humans)
Reasons to preserve biodiversity: aesthetic, medicine, food, interactions
What to do to protect it: patrolling reserves, planting species, explore
Why Study Biodiversity?
Interconnectedness → the effects that the decline of a species will have on another species
→ all living things interact with each other – eating, services
→ ex. Egrets team up with carnivores to eat their parasites and see further, carnivores share food supply and protect
Evolutionary change → how organisms came to exist and change overtime
Enable our planet to continue sustaining/ preserve life
More biodiversity = more stability = more the ecosystem can adapt to change → the more species, the better an ecosystem can withstand climate change, disease and pest infestations
What Destroys Biodiversity?
Habitat loss
Introducing invasive species
Overexploitation (hunt, cut trees)
Pollution of water, air, soil
Climate change & global warming
Why do we need Biodiversity?
Ecosystem stability
Food supply
Medicines
Tourism/forest industry
Natural earth cycles
Extinction
Extinction is normal as species get replaced → 10-100 species/yr is normal
Bad when mass extinction → estimated 27,000/yr
How Can We Help?
Habitat restoration – if we can figure out what we do to harm the environment, we can fix it
Zoos and Captive Breeding – breeding of endangered species and then bringing them back to the environment
Protect habitats and species – from poachers or setting preserve zones
Reduce climate change and fossil fuels
LESSON 2 - Classifying and Sorting Living Things (Taxonomy)
Taxonomy = the science/study of naming, classifying and identifying species
3 Domains of All Life:
Bacteria
Archaea
Eukarya (complicated cells with a nucleus)
Carolus Linnaeus:
Swedish botanist
1707-1778
Good – he divided and classified all living things and created a formal system
Bad – he did this with all living things, including humans (racism invented → listed characteristics of groups of humans)
Because of him → invented 1.2 million species identified
Levels of Classification:
Doctor King Phillip Calls Out For Golden Shekels
Domain
Kingdom
(Ex. Animalia → multicellular, animal cells, eat food, live birth, hair)
Phylum
Class
Order
Family
Genus
Species
LESSON 3: Scientific Naming - Binomial Nomenclature
Each organism’s name has 2 parts:
Genus (Capitalized)
Species (lower case)
Problem with common names:
Can’t name by describing (ie. single celled organisms)
Misleading
Do not have a system (ie. looks, colour, geography)
Different parts of the world have different names for something
Proper names:
Embedded list of criteria
No language barrier
Only one word for something
Scientific Naming:
Use characteristics to name (ie. all cats are in the Felis genus)
How to decide if 2 individuals are the same species?
Morphology → similar shape, size, structure (do they look similar)
Not the best/most accurate
Biology → they can naturally produce viable offspring (fully functional babies)
Preferred definition
Does not work for species that reproduce asexually or that do not exist
Phylogeny → the study of relationships – close evolutionary relationship (did they evolve together)
*** All these traits must be observable
Ex. A mule is the result of a donkey and a horse, but it cannot reproduce (sterile) therefore does not have a scientific name
A species is a group of individuals with similar characteristics that produce real viable offspring
LESSON 4 - Phylogeny – How Species are Related
Phylogeny = a visual representation of the evolutionary history of a species over time
If we know what species are related → better testing and better medical breakthroughs (vaccines, drugs)
Phylogenetic Tree
Starts at the root (the past)
The width of the tree looks at how different species are
Nodes
Clades → the most closely related
Outgroups
Evidence of Evolutionary Relationships
How much DNA in common
Anatomy – what body looks like
Physiology – how does the body function
Clade = a group that has a single shared ancestry → names for a group with characteristics they share (ex. Mammals, amniotes, tetrapod, vertebrates)
LESSON 5 - Dichotomous Keys
WHAT?
→ A tool identify different similar species when we see them
Di = 2 → always 2 options
How to make a good dichotomous key?
Use constant characteristics rather than ones that disappear or vary with the season (ex. A deer does not have antlers in winter)
Need to use characteristics that can be directly observable (ex. A penguin has a white belly, sharp beak, form mating pairs) → physical or behavioral
Use quantitative (number) measurements with an amount or dimension rather than vague terms (big/small)
How to monitor air?
Physical tests
Biological tests
Chemical tests
Lichens:
A collaboration of fungi and algae (fungi farming the algae)
They take all their water from the air → incredibly sensitive to air pollution
20,000 species (crustose, foliose, fruticose – beard)
LESSON 6 - 6 Kingdoms of Life
Eubacteria
Either heterotrophs or autotrophs (eat other things or makes things themselves)
Have a cell wall that is made of peptidoglycan
Simple organisms lacking nuclei
Photosynthesis
Archaebacteria
Live in extreme environment (volcano, zero oxygen, pool of arsenic)
Have a cell wall (not made of peptidoglycan)
Protists
Most are single celled, some are multi-celled (exp. kelp/algae
Some have a cell wall
Can be autotrophic, heterotrophic or both
Fungi
Multicellular
Eukaryotic
Heterotrophic
Reproduce sexually and asexually
Have a cell wall – Chitin (used for dissolving stitches)
Terrestrial
Plants
Multicellular
Eukaryotic
Autotrophic (exceptions include venus fly traps, pitcher plants – because don’t have enough Nitrogen in soil)
Reproduce sexually or asexually
Most are terrestrial, some aquatic
Photosynthesis
Animals
Multicellular
Eukaryotic
Most reproduce sexually
Heterotrophic
Live in terrestrial and aquatic habitats
Who am I Questions *** on test
Kingdom Animalia Key Features:
Organization → whether you have tissues (specialized cells to do something) or not
Classification = cell → tissue → organs → organ system → organism
Ex. sea sponge
Symmetry → two parts are the same when split
Radial symmetry = symmetrical all around
Bilateral symmetry = 2 sided symmetry on outside
Ex. jellyfish
Body Cavity → are you a tube within a tube
Acoelomate – have a tube but everything is attached
Pseudocoelomate – half and half
Coelomate – tube within a tube that are separate → humans can sit still while digesting
Segmentation → repeating body parts (genes that are copy pasted)
Ribs, limbs, spine
*** Taxonomy is not a law of nature
LESSON 7 - Microscopic Life
Eukaryotic = 10x bigger than bacteria, has DNA, has a nucleus
Why Care?
Bacteria affects the environment
Decomposers, food spoilage, cyanobacteria (oxygen), disease
Archaea are used for industry
DNA testing relies on enzymes that can survive at 70+ degrees celsius, diagnosing diseases, intestinal issues
Viruses
Prevention of disease, genetic engineering
Eubacteria | Archaea | |
General | Prokaryotes (no nucleus, 10x smaller than eukaryotic cells, 1 chromosome DNA, unicellular) | Prokaryotes (no nucleus, 10x smaller than eukaryotic cells, 1 chromosome DNA, unicellular) |
Shape | Spheres (Cocci), Rods (Bacilli), Spirals (Spirilla) | Spheres (Cocci), Rods (Bacilli), Spirals (Spirilla) |
Group | Many working together – some take on specialized tasks Ex. (Streptococci, Staphylococci, Diplococci) Diplo = 2 Strep = line Staph = clump | Diplo = 2 Strep = line Staph = clump |
Cell Wall | Have a cell wall made of protein and sugar combined
| Made of either protein or sugars
|
Nutrition |
|
|
Habitat | Mesophiles (moderate climates)
| Extremophiles (Live in extreme environments)
|
Reproduction | Asexually → copy DNA then split in half (Binary Fission) Sexually → Conjugation (plasmid/DNA exchange) – can pick up random pieces of DNA then copy it and share it with another Can shut down their cellular processes and create an Endospores (protective shell state) | Asexually → copy DNA then split in half (Binary Fission) Sexually → Conjugation (plasmid/DNA exchange) – can pick up random pieces of DNA then copy it and share it with another |
Other |
Earth formed 4.5 bya
First bacteria = 4.0 bya
Multicellular eukaryotes = 2.0 bya
Endosymbiosis Theory
2 prokaryotic cells – bigger one ate the smaller one
Did not digest it → little got protection and food and big one gets help for digestion & chemicals
After a while → it reproduces with both cells
“Inside working together”
That smaller one became the “mitochondria” of the cell
→ have 2 membranes (sucked in) and their own DNA
Formation of Eukaryotic cell
If eat another photosynthetic bacteria → plant cell
LESSON 8 - Viruses
Viral | Bacterial | |
Is it contagious | Yes | Sometimes |
Treated with antibiotics | No | Yes |
Examples | Common colds, flu, chicken pox | Strep, pneumonia, UTI |
Examples of Human Viruses:
Flu
Cold
Herpes or cold sores
Measles
What does it mean to be living?
Growth and development
Energy metabolism
Homeostasis
Adaptation as a species
Response to stimuli (things in external environment – movement and adaptation over a period of time)
Cells
Reproduction
Viruses…
Are: organized, evolve
Maybe: reproduction (only with a host), homeostasis, react to environment
Dont: grow and develop, metabolism
Classification:
What they look like (size and shape of capsid – protein coat surrounding RNA and DNA)
By type of disease
By who they affect (host)
Geometric
Virus Morphology
Extremely small!
17 nm - 400 nm in diameter
Smaller than light – need electron microscope
Viruses consist of:
DNA/RNA – code of just what the virus does
Surrounded by a membrane – in a protein coat (capsid)
Spikes = keys → spike has to match the receptors part of the host cell to get in (part that changes the most)
Optional: Envelope made of fat
Host Range:
The range of organisms a virus is capable of infecting
More concerning when viruses change their host range by mutations
All life forms have viruses
Virus Reproduction
Tells what kinds of disease they cause us (Lytic VS Lysogenic Cycle)
Lytic Cycle: (Destruction Cycle)
Phage attaches to the cell → spikes must match up with host
Phage DNA enters the cell
Hijacking = Host DNA now has a new instruction manual → host DNA breaks up
New virus cell forms
Lysis → new viruses break out of the cell
Can take hours to days (immediate)
Lysogenic Cycle: (Virus Hides)
Aka Retroviruses – Ex. Herpes, HIV
Worried because can only treat when go to Lytic Cycle
Attachment
Insert DNA
DNA merges and becomes part of the host DNA
When cells replicate → copy both virus and cell DNA
When stress (physical, mental, temperature) → causes virus to separate and begin Lytic Cycle
Not all viruses go into Lytic Cycle
Can take a long time
Viruses for Genetic Engineering
Take viruses → replace DNA and then reinsert them back into the body
Vaccines:
Some viruses mutate a lot, and some remain the same (vaccines works for this)
Immune cells on lookout for specific germs
Immune cells (WBC’s) arm and replicate → launching antibodies when detecting a virus
Leave behind memory cells specific for the attack of the full scale virus attack
Vaccine sends dead (destroyed to point of non-function) version of virus or parts of the virus – often just the spike
So memory cells are prepared if in contact with actual virus
COVID Vaccine:
Iserts RNA (information on how to create the spike) → prevents infection from getting bad
People who cannot get vaccinated:
Too old
Too young
Immunocompromised
Herd Immunity:
If only some people get vaccines → disease spreads rapidly
Goal → enough vaccinated (most of the population) people to separate people who are unvaccinated are less vulnerable
Protecting others
Will lessen the spread of disease / stop it
The more contagious the disease = the more % of population should be vaccinated to have herd immunity
Bio - Unit 2 Notes
Evolution
LESSON 1 - Intro
Evolution = the gradual change in traits of a population over time
Change at a population wide level
Very situational
Depends on 2 things:
Who survives to maturity
Who gets to reproduce
Evolution is a Theory → Explanation of a set of related observations or events based upon proven hypothesis and verified multiple times
Ex. Atomic theory, theory of relativity
Evolution Stories / VIST
Variation → we are not all identical
Inheritance → traits that are inheritable
Selection *
Time → generations
Evolution selects the best available answer (like multiple choice)
Example of VIST
The individuals of the species have many variations of the trait: A, B, C
This trait is heritable: Individuals with variation A will have babies w/ variation A
Colour is an inheritable trait
Individuals that had variation A were better able to survive and/or reproduce {selection}
Individuals with variation B were more likely to die young
Individuals with variation C lived, but found it harder to affect a mate
After several generations [time], most individuals of the species show variation A
Variation = any genetic differences amongst individuals in a population
May be structural, physiological, behavioral
Adaptation = a genetic difference that helps an organism survive and/or reproduce in a particular environment (can be advantages)
A variation that is useful for its environment
Ex. moths being peppered or black
Evolution is a natural process → but humans can interfere
Ex. Climate change, genetic engineering, artificial selection
Natural Selection:
Type of selection where you have to survive (predator and prey)
Type of selection where the better variations are the ones who continue to survive and not die off
3 Types of Natural Selection:
Directional Selection → where ONE extreme is favoured and the variation frequency continues to shift in one direction (ex. The moths)
Disruptive Selection → where BOTH extremes are favoured and they both continue to survive in different ways
Stabilizing Selection → where INTERMEDIATES are favoured and their variation continues to survive
Artificial Selection:
Type of selective pressure exerted by humans to “improve” desirable traits
Type of biotechnology
Pros:
Produce more food with same space
Con:
Less genetic diversity → risk of disease
Selective Pressure:
Any phenomena which alters the gene frequency (variation) of living organisms within a given environment
Antibiotic Resistance:
Bacteria mutates randomly → some can develop mutation that makes them antibiotic resistant (Variation)
Normally have enough good bacteria to prevent resistant bacteria from taking over
When using antibiotics → kill susceptible (non-resistant) bacteria but resistant bacteria survives (Selection)
When you don't take all the antibiotic pills the remaining bacteria multiples
The resistant bacteria now has lots of space to grow (Time)
Genetic engineering → able to pick the offspring, mess with Variation/Inheritance
Mimicry → type of camouflage – type of adaptation
If not camouflage, need to be good at hiding or have bigger problems of survival (are poisonous)
LESSON 2 - 5 Fingers of Evolution (Selection part of VIST):
Pinky → Genetic Drift (random chance) → The process of change in the variation of a population due to chance or random events
randomness can significantly affect what you have – smaller populations are more affected by random events
Founder effect → A few members of a large population leave to start a new population in somewhere new – the smaller the groups are the more effect this has on the population (ex. Ashkenazi Jews can have disorder called Tay Sachs)
Bottleneck effect → Random reduction in a population (from large population to small population – happening within the same place (ex. Natural disasters – In a population of 100 people with 3 colour blind people, there is a tsunami, and 75 people die. None of the colour blind people died)
Ring finger → Sexual Selection → The process whereby organisms with certain sex characteristics tend to reproduce more
pressure (physical, behavioural)
Ex. Male deer fight using their antlers to attract and keep mates
Middle finger → Mutation → The changing of the structure of a gene, resulting in a new variation
Ex. Some humans are born without wisdom teeth
Pointer finger → Gene Flow/Movement → The transfer or movement of genes/variation from one population to another
Ex. A group of Inuit from Nunavut move to Nova Scotia
Thumb → Natural Selection → The process whereby organisms better adapted to their environment tend to survive
Ex. Owls with good infrared vision are better able to see prey
LESSON 3 - Sexual Selection
Survival is not enough to pass through evolution → need a mate to reproduce and pass on your genes
Sexually selected traits:
Presents (food, sperm)
Try to look nice
Fighting for your mate
Generally the “try hard” in the relationship is males → because of the energy exertion (female to have offspring is a major energy investment)
The partner that invests less energy is the try hard
2 Categories:
Trying to assert dominance → Intrasexual selection (within one gender)
Women typically go for looks and men go for physical damage
Trying to attract → Intersexual selection (between genders)
Balance:
Optimal balance between natural and sexual selection
Ex. Peacock tails must be long to attract a mate but not too long to prevent them from flying away from prey
Disruptive selection = both extremes
Ex. short stalk eyed flies mate with each other and long stalk eyed flies mate with each other
Competing goals:
Males want as many mates
Females want the best mate
Ex. Males in water striders have evolved to have “rape arms”
- Females counter evolved ridges on their backs
Evolutionary arms race → constantly evolving with competing goals (happens for non-monogamous species)
Red Queen Hypothesis:
Males and females always evolving to one up each other (negative)
Idea that to maintain the current balance → you can’t stay the same in evolution
In order to maintain balance you have to keep evolving (just to stay the same)
Can apply to same species (sexual) or different species (prey)
Gender Dimorphism:
When males and females look extremely different → non-monogamous (ex. Mandarin ducks)
When monogamous → they typically look alike (ex. penguins)
Coevolution:
2 species evolving in response to each other
Any relationship between species (positive or negative)
Ex. Predator and prey, bees and flowers
LESSON 4 - Speciation
Speciation event happened when there is a split in a phylogenetic tree → something happened where the 2 groups are no longer reproducing
Speciation = the process by which groups evolve to become distinct species
Species = group of organisms consisting of similar individuals which can produce viable offspring
Can happen at 2 different speeds:
Gradualism = species that gradually/slowly get more different
Punctuated Equilibrium = when environment quickly changes there is a sudden big change – and then not changing after
Biological Species Concept: Reproductive Isolation
The two groups will not reproduce because they are 2 different species
Behavioural reproductive mechanism
Story of Speciation Event:
Step 1 → stop two groups from interacting – gene flow between 2 groups is disrupted
Step 2 → genetic mutations/variations accumulate – time makes these groups change
Step 3 → 2 groups are now reproductively isolated when together again
Allopatric Speciation → the 3 steps include a physical barrier (happens more often/easier)
Sympatric Speciation → the 3 steps include a preference/behaviour (non-physical) – long distances
Adaptive Radiation
If species goes somewhere new where nothing like it exists → lots of opportunities to succeed
One species (common ancestor) that can become many new species
Can be allopatric or sympatric
Relatively rapid
Ex. chains of islands (isolated, many habitats)
Reproductive Isolation Mechanisms:
How we know things are separate species
Divided into 2 groups:
Pre-zygotic → prevent from making a zygote (first cell with sperm and egg not coming together)
Habitat Isolation → if don’t live in the same spot, won’t mate (same geographic area yet separate or different habitat)
Temporal Isolation → reproductive cycles for mating occurs at different times (day vs night / seasonal)
Behavioural Isolation → distinct mating rituals not recognized by another species (what they like/dislike)
Differences in the behaviour prevent mating
Because there is no gene flow between populations, evolution occurs
Mechanical Isolation → structural differences in reproductive organs (the parts don’t fit)
Gametic Isolation → Gametes (sperm and egg) must be compatible (chemicals on both ends don’t match) – the sperm cannot fertilize eggs
Recognized each other by cell surface markers
Very important in aquatic species → broadcast spawners (they release sperm and egg into ocean hoping the waves will let them reproduce)
Ex. sea urchins (they have to match up or else will not fuse together)
Post-zygotic → prevent zygote/hybrid offspring from reproducing (sperm and egg come together but prevent from having baby)
Zygote Mortality → Initial cell formed upon fertilization dies
Genetics, mom cannot carry, chemically not compatible enough
Hybrid Inviability → have a baby, but the baby cannot live a full life (very weak, sickly, die early, cannot reproduce)
Ex. Leopard + Lion = Leopon (bad)
Hybrid Infertility → Offspring strong/fit and adults are healthy, yet are sterile (can’t reproduce)
Ex. Mules and Ligers
Hybrid Breakdown → First generation hybrids are viable and fertile BUT offspring in 2nd generation (when those hybrids try to reproduce) they are feeble or sterile
Mostly see this in plants
Plant Hybrids:
Humans have genetically made new plants, fruits
Ex. Lemon (Citron and bitter orange)
Experimental Results:
Dianne Dodd fed one group of fruit flies who evolved as she gave one set of fruit flies sugary foods and the other starchy foods
Examined the effects of geographic isolation and selection on fruit flies
The flies from the same group preferred to mate with each other
THEORISTS:
Cuvier = Catastrophism → Punctuated equilibrium
Lyell = Uniformitarianism → Gradualism
Lamarck = Inheriting acquired characteristics (whatever you try to become – that’s what you gain)
Darwin = Natural selection – all of things that were not strong died off
Both had idea of adaptation but HOW was different
LESSON 5 - Supporting Evidence
Fossils
Sign that things have not always been this way
Found in top layers of rock more closely resemble living species today – deeper is more different
Not all organisms appear at the same time/every layer
Appear in chronological order
Not easy to make → need to be buried very deep and very fast before decompose (so much pressure and heat) – atoms of their body get replaced by rock
Can make good predictions of lifestyles of fossils – Bones can tell how they moved, ate, what muscles → bumps and ridges can tell where muscles and tendons attaches
Can’t learn about soft tissue – if none preserved, hard to tell → can’t guarantee
Transitional fossils → can see every step of the journey
Ex. homosapien and homo neanderthals look very similar
Horses (used to be extremely small with 4 toes)
Archaeopteryx → some traits in modern birds (wings) and reptiles (tail vertebrae, beak, claws) – disruptive selection
Biogeography
Study of locations of organisms around the world which provides evidence of descent with modification (continental drift)
Species that look alike tend to live near each other
Continental Drift = why closely related species exist in different continents → dates back to Pangea continent
Anatomy
Vestigial Structures
A structure that is a reduced version of an ancestral structure
Ex. Whales have hip bones because their ancestors once had legs but not functional or useful anymore
Ex. human tail bones
Human pulmonary tendon (thumb and pinky, tilt wrist) → used to be useful for grip strength but useless now
Human wisdom teeth → used to wear away regular molars and needed new ones – but now is useless
Divergent Evolution/ Homologous Structures
When 2 things gradually get more different (diverge)
Species that had a recent common ancestor – used to be similar and then diverged
Occurs when populations changes as they adapt to different environmental conditions
Look alike on the INSIDE
Bone structure similar → 1 bone, 2 bones, a bunch of little bones, fingers
Same bone structure, different function
Evidence of recent common ancestor
Ex. human arm and whale arm
Convergent Evolution/ Analogous Structures
Even though started off as different species → similar traits arise because species have independently adapted to similar environmental conditions
Evolved for same for same reason but from different starting materials → same selection pressure, different origin
Not because share the same common ancestor
Ex. birds and bees both have wings, but no recent common ancestors
Look alike on OUTSIDE but structurally not the same
Different bone structure, same function
Evidence of similar environment
Ex. sharks (fish) and dolphins (mammal) but have fins, tails
Embryology
From zygote into a baby
Have tails, gills
Molecular Biology/ DNA
Makes change hard to track
Prefer to use mitochondrial DNA → have their own DNA and ONLY comes from MOM – perfect match
No negative consequence in mutation in this DNA
LESSON 6 - Altruism
Altruism = self-sacrifice for someone else
Success in group settings or family units
Kin Selection in Humans:
Family relationships matter
Ex. Person or Dog test → asked who would save (person – different levels of relatedness or dog) – the more closely related the humans, choose humans, the more distantly related, choose dog
Kin Selection Theory:
Self sacrifice depends on close family relationship because saving your DNA is saving my DNA – “secret selfishness”
Family shares DNA
Lose energy, food, life → want someone with same genetics as you
Most higher level species are more invested in family members
If family in danger → more likely to do things than for others in danger
Close family unit was more successful
Reciprocal Altruism Theory:
Unrelated organisms frequently cooperate → Cooperation/altruism depends on returning the favour
Does not rely on family
Giving favours to get a favour
Competition is not always the winning strategy – cooperation can win
Ex. Bird flight formation → Front bird takes air resistance off the others in the back – save energy
Ex. Fish schools make it harder for middle fish to get eaten
Ex. Primates groom non-relatives to make sure there are less parasites in group
Sometimes leads to a Red Queen scenario where one tries to cheat
What is required for Reciprocal Altruism:
Communication
Long-term memory
Able to recognize individuals (sensory)
Birds, fish, primates
Game Theory - Prisoner’s Dilemma:
How much do you trust the other person
If both cooperate → best outcome
If both defect
If only one defects → worse outcome
According to math → better to defect, but depends on number of rounds
When unknown number of rounds → better to cooperate
Cooperate from the beginning and then copy what the other person does = “tit for tat”
How does cooperation start?
Starts when there are 2 cooperators
Changes from always defecting to going for “tit for tat”
Bottleneck effect → kin selection in the small group, then cooperation spread if the population ever reunites with others
Selection for cooperation:
Some traits may be a problem for an individual, but but beneficial to the group – or vise versa
Individual success vs group success
Ex. Hawk dominates crow but many crows dominate hawk (group success)
Ex. Hens peck other hens for infertility (individual success)
Adaptations for Cooperation are sometimes more important than Survival Traits:
Sometimes adaptations that help us cooperate better are more important than even individual survival traits
Ex. humans needed communication so evolved to have pharynx and larynx next to esophagus (only epiglottis to stop from choking)
Bio - Unit 3 Notes
Genetics
Cell part | Function | Equivalent part of WCI |
Cell membrane | Regulates what goes into and out of the cell (liquids and solids) | Doors of school |
Mitochondria | Converts energy from food into energy a cell can use | Generators |
Nucleus | Contains genetic material (DNA) and controls the use of genes; found in eukaryotic cells | Principle |
Cytoplasm | Fluid that surrounds the organelles to hold them in place | Hallways |
ER | How the cell sends things around the cell and makes proteins (internal transport) | Legs for walking |
Vacuole | Storage units for water and sugar | Backpacks |
Centrioles | Perform mitosis (cell division) – only in animals | Classroom doors |
Lysosome | Taking old materials and making new things out of it | Trash can |
Cell Wall | For structural support in plants | Brick walls |
Chloroplast | Photosynthesis in plants | Cafeteria |
LESSON 1 - DNA
DNA = Deoxyribonucleic Acid
Information is in the rungs of ladder
When cells active → DNA has to be opened
But when want to move, change or make reproductive cells → DNA has to be coiled to not get broken
Changes that happens when broken = how bad the effect will be
Genetics = study of inheritance
Everything has the machinery to make and copy DNA
Genetic Material of Cells:
GENES – portions of DNA/units of genetic material that CODES FOR A SPECIFIC TRAIT
Each chromosome contains many genes
The number of genes does not tell you how complicated you are
DNA is made up of repeating molecules called NUCLEOTIDES (4 letters – ACTG)
Nucleotide = phosphate + sugar + nitrogen base (¼ chemicals – ACTG)
Different arrangements of nucleotides in DNA is the key to diversity in living organisms
The order of the letters in the DNA matters bc can code for something different
Rungs of ladder = bases
Outside = phosphate and sugars
Called double helix → there are 2 and attached the bases
Nitrogen Bases:
1. Adenine
2. Cytosine
3. Thymine
= pYrimidines (C & T have a Y in it)
4. Guanine
= Purines
Complementary Rule/ Chargaff’s Rule:
DNA has specific pairing between nitrogenous bases
Adenine + Thymine (straight sided letters)
Cytosine + Guanine (curved letters)
Their amounts in a given DNA molecule will be about the same
DNA Replication: Each strand of the original DNA serves as a template for the new strand
The DNA molecule unwinds, copies and then fills in the blanks → 2 identical new complementary strands following the complementary rule
Ex:
AT
CG
CG
TA
=
AT AT
CG CG
CG CG
TA TA
This is called Semiconservative DNA replication
Because the two strands are loosely connected by Hydrogen bonds
The “code” of the chromosome is the specific order that bases occur in.
DNA controls cell function by serving as instructions to make PROTEINS
Proteins perform almost every body function
CHALLENGE: Try using only four letters [T/A/S/R] to make as many words with different meanings as possible
DNA Structure:
Cannot be organized in a clump
Double helix wrapped around proteins which are wrapped up around each other
DNA is wrapped tightly around histones (proteins) and coiled tightly to form chromosomes → now can be read and travel
ANSWER
1. Why is DNA replication necessary?
Need new cells to grow/develop, reproduce, maintenance of body, repair of damage/injured cells
2. When does DNA replication occur?
Before mitosis occurs
3. Use the complementary rule to create the complementary DNA strand:
AGCTAGAGCAGT
TCGATCTCGTCA
Summarize the relationship between genes & DNA
Genes are a section of the DNA which code for a specific trait/protein
Describe the overall structure of the DNA molecule
Double helix – connected by
Ladder shape
Nucleotide = phosphate, sugar, nitrogenous base (ACTG)
4 kinds of bases
NAMING DNA
Chromatin = uncoiled DNA being used by cell → for transcription | Chromosome = bundled DNA (copied during interphase) → to transport |
Sister Chromatids = identical pieces of DNA bound by a centromere
| Homologous Chromosomes = NOT identical but code for the same traits
|
LESSON 2 - Mitosis
The cell cycle includes what 3 phases? What happens in each phase?
Interphase (pre-mitosis)
Before mitosis
The cell does normal cell activities (making cell proteins)
What the cell does majority of its life
DNA replication
Mitosis (only 4 stages during the cell division process)
Prophase
Metaphase
Anaphase
Telophase
Moving the DNA around
Cytokinesis (post cell division)
The splitting of the cells
What is DNA called when it is…
Uncoiled?
Chromatin
Coiled up?
Chromosome
An exact duplicate half of a chromosome?
Sister chromatids
How many different pieces of DNA do human cells have?
46 (23 from each parent)
Why do we need to make more cells (via mitosis)?
Mitosis produces new cells, and replaces old ones, or damaged cells
Developes growth in the body
What do we call the resulting new cells at the end of Mitosis?
2 daughter cells
What are the 4 phases of mitosis?
PHASE | Prophase | Metaphase | Anaphase | Telophase |
What Happens | The chromatin condenses into 2 chromosomes. Each chromosome has 2 halves called a sister chromatid. The 2 chromosomes move to either ends of the cell. The nucleus disintegrates. | Chromosomes line up in the middle of the cell | The sister chromatids pull apart and split up to opposite sides of the cell. | The 2 daughter cells start to split up (pinching membranes). Each newly forming cell makes a nucleus. Chromosomes uncoil to make chromatin. |
Picture |
What happens in Cytokinesis? What does the word Cytokinesis mean if you “English language translate it” (as Ms.W loves to say)?
Membranes of the cells divide completely → Cell Movement
After Mitosis and Cytokinesis: 2 genetically identical daughter cells have been produced.
LESSON 3 - Meiosis
= How we take body cells and turn them into gametes
Gametes don’t end up exactly the same (siblings)
Goal → increase variation
Sexual Reproduction = 2 parents reproduce → unique offspring
Chromosomes = bundles of DNA → every species dif number
Gametes must have half the humber if chromosomes as body cells
Diploid (2n) = the full amount of chromosomes (in a body cell) → theres 2 copies of each chromosome (1 mom, 1 dad)
46 in humans
Haploid (n) = the number of chromosomes in a gamete → half the normal amount
23 in humans
Meiosis
Built in mechanisms to share and change DNA to create more variation in offspring
Identical copies do not count as new genes
Only want half of DNA to be in our gametes
Result of the reduction to haploid is that there can be huge genetic variation within members
Law of independent assortment: random arrangement of homologous pairs → crossing over results in more variation
Gametes generation:
Energy difference starts early
Cytokinesis step differs
Nondisjunction: chromosomes/chromatin/chromatids do not separate properly and results in gametes with the wrong number of chromosomes → results in trisomy or monosomy
Could result from death to complications
Trisomy 21 → 3 copies of the 21st chromosome (down syndrome)
Monosomy → Missing one chromosome
Spermatogenesis
| Oogenesis
|
Chromosome Abnormalities:
Deletions: A portion of the chromosome is missing or deleted.
Frequently on chromosome 5
Duplications: A portion of the chromosome is duplicated = extra genetic material.
Inversions: A portion of the chromosome has broken off, turned upside down, and reattached = genetic material is inverted
Substitution: A portion of the chromosome has substitutes itself for a part of another chromosome
Translocations: A portion of one chromosome is transferred to another chromosome
LESSON 4 - Heredity
Initially → inheritance was regarded as paint mixing theory → mixing colours infinitely
However if that were to happen → we would all look identical
However idea that there is a smallest particle (trait) that mixes → mixing of multiple beads
Particulate Inheritance Theory:
Particles of inheritance = DNA
Specific variation of a gene (one trait) = Alleles
- Ex. gene = eye colour/ allele = brown
The combination of alleles that an individual has for a specific gene (Genetic instructions) = Genotype
- Ex. allele 1 = Brown (B), allele 2 = blue (b), Genotype = Bb
Observable characteristics (physical appearance) = Phenotype
- Ex. brown eyes, tall, brown hair
Genetics = the study of heredity → how traits are passed from parent to offspring
Different traits are inherited by different patterns of inheritance
Gregor Mendel (Aka father of genetics)
Monk and scientist
Had a garden → looked at traits of pea plants
He forced plants to breed (using paintbrush) how he wanted
Did this for years with thousands of plants
At the start “pure breeds” (P - parent generation) → tall plants with each other and small plants with each other
Then did this so that each of the variations were “pure breeds”
He then mixed tall (TT) and short plants (tt) which always produced tall plants (Tt) → Offspring called F1 (first filial generation)
Then bred F1 generation to make F2 generation (75% tall, 25% short – 3:1 ratio) → TT, Tt, Tt, tt
Question: how did short plants reappear in F2 generation → discovered 2 rules
LAW OF SEGREGATION:
Came up with idea of homologous chromosomes and meiosis
Each tall plant from the F1 generation carried 2 ALLELES (2 copies of the trait)
DOMINANT TRAITS RULE:
Strong traits covered weak traits
Stronger/ always expressed = Dominant (T)
Weaker/ only when dominant not expressed = recessive (t)
2 copies but only pass on one trait:
1 tall allele → Dominant
1 short allele → Recessive
Heterozygous → if 2 alleles for a trait are different (Aa)
Homozygous → if 2 alleles for a trait are the same
AA = homozygous dominant
aa = homozygous recessive
PUNNETT SQUARES:
Not guaranteed
Every time have a kid, results can vary (because people don’t have that many kids)
Parent #1 had to be heterozygous if child has no widow’s peak
EX. #2: Tongue rolling
Genotypic Ratio:
RR = ¼
Rr = 2/4 or ½
rr = ¼
Phenotypic Ratio:
Rollers = ¾
Nonrollers = ¼
DIHYBRID CROSSES:
2 punnett squares for 2 traits at a time (2 separate chromosomes)
If heterozygous for both traits → 9:3:3:1 phenotypic ratio
Ex. Ffdd x FfDd
Freckles = dom
Dimples = dom
Freckles Dimples
What are the odds of both?
¾ x ½ = ⅜
What are the odds of neither?
¼ x ½ = ⅛
What are the odds of freckles and no dimples?
¾ x ½ = ⅜
LESSON 5 - More Complex Patterns of Inheritance
→ Most traits are not simply dominant / recessive
Incomplete Dominance = neither allele is completely dominant over other → Heterozygous (a third new) phenotype is created = middle ground
Ex. Pink flowers from red and white
Codominance = BOTH alleles are equally dominant and expressed
Ex. Roan cows = red and white patches
Ex. in humans → sickle cell anemia
Protein hemoglobin gets built wrong (straight line) causing cell to become sharp and pointy → causes blood clots easily and not great at carrying oxygen
However very difficult for malaria to attach to sickle cells → common in people with recent African ancestry
Heterozygous (HbA HbS) = sickle cell trait → best of both worlds for people in malaria environment
LESSON 6 - Multiple Alleles
More than 2 alleles possible for a given trait/gene
Allows larger amounts of variation – both genotypic and phenotypic
Although more alleles → can only inherit 2 at a time
There is an order of dominance
Ex. Blood type = 4 blood types in 3 alleles
Always on lookout for antibodies that are not you → will clot
Antigens = you
Antibodies = Immune system trying to fight things that are not you
IA = A antigen on RBC (IAIA , IAi)
IB = B antigen on RBC (IBIB, IBi)
i/ O = neither A or B antigen (ii)
AB = both A and B antigen (IAIB)
Phenotype | Possible Genotypes | Allele (antigen) on RBC surface | Can donate blood to | Can receive blood from |
A | IAi IAIA | A | A, AB | A, O |
B | IBi IBIB | B | B, AB | B, O |
AB | IAIB | AB | AB | A, B, AB, O |
O | ii | O | A, B, AB, O | O |
AB = universal recipient → everything is them
O = universal donor → but can only receive from themselves
Rh Factor
Inherited antigen (protein) on the surface of RBC
+ blood type = have Rh protein (more common)
– blood type = don’t have Rh protein
Tells you what antibodies your body makes (Rh - [2 - alleles] is against Rh +)
Important → indicates whether blood of 2 different people is compatible when mixed
Examples:
Baby
If mom and baby blood type don’t match up, then mom can create anti-D antibodies which can lead to the baby having Rhesus disease
Issue when woman is - and baby is +
Can cause misscarriage
Blood transfusions
→ Rh + can receive from Rh + and Rh –
→ Rh – can only receive Rh – (because makes anti-Rh antibodies)
Testing Blood Type:
Take antibodies from blood and test different antibodies
Blood Coagulation → Reaction will happen if it reacts to anti-itself
Ex. If blood type A (with B antibodies) interacts with B blood – then B antibodies will clot the B blood
Reacts with anti-A antibody | Reacts with anti-B antibody | Blood type |
Yes | Yes | AB |
Yes | No | A |
No | Yes | B |
No | No | O |
LESSON 7: Polygenic Traits
Polygenic Traits = Expression of a trait by several genes → shows continuous variation
Ex. eye colour, height, skin colour
Multifactorial Traits = control of expression of a trait by several genes and environmental factors → shows continuous variation
Ex. skin colour → genetics and sunlight
Ex. human height → genetics and nutrients fed as a child
How to see what is genetic/environmental?
→ Identical twins – if have only the same some of the time, then it is most likely an environmental trait
LESSON 8 - Epistasis & Linked Genes
Epistasis
One gene depends on another gene for it to be expressed → controls whether you even see the results of the other gene
Ex. Llama – gene for wool colour and gene for expression of colour
Linked Genes
Discovered by Thomas Hunt Morgan → expected Mendel’s ratio (9:3:3:1 – independent assortment) when breeding fruit flies (eye colour and gender)
The traits that he happened to have picked were linked → physically on the same chromosome
More looked at sex-linked traits
Linked Gene = physically sit close together on a chromosome, making them likely to be inherited together
Further apart → crossing over more likely to separate them
Sex-Linked Traits
Gene is attached to the X chromosome only, not Y (or vise versa)
More commonly expressed in males
Carrier = heterozygous
Punnett Square → X chromosomes first, dominant trait first
Phenotype ratio – separate by gender
Ex. red-green colour blindness = X-linked, recessive
Colour blind man x woman carrier
Normal vision man x woman carrier
Daughter = 50% odds of being carrier but no colour blindness
Son = 25% regular, 25% colour blind
Too Many X’s
Women have 2 X chromosomes but only needs one to survive
Some cells use one X chromosome and some in the body use the other – the one not used gets “turned off” / bundled
LESSON 9 - Pedigrees
Tracking disease/traits through families’ phenotypes to find inheritance patterns
Dominant = shows up in EVERY generation – never skips
Recessive = skips generations – parent(s) are heterozygous
Autosomal = not on sex chromosome
Sex-linked = on sex chromosome
Y-linked → only males carry trait
X-linked recessive → mostly sons inherit from normal parents
X-linked dominant → sons and daughters inherit from affected parents
Questions:
Difference between a Punnett square and a Pedigree
Punnett = predicting offspring
Pedigree = looking at family traits, pattern of inheritance
Can doctors predict who will get a particular disease based on a genotype for one gene alone?
If the gene is dependent on one gene then yes (ex. Hemophilia, Tay Sachs)
If the gene is multifactorial (multiple genes and environmental factors) then not really – can say risk level
(ex. Diabetes, heart disease) → by controlling environmental factors, you can adjust your risk
Why might factors, such as food choices, pollution, smoking not have the same effect on all people?
Answer in Q2
What are some advantages and disadvantages of genetic testing?
Advantages: proactive things you can do when finding genetic disease to prevent serious effects
Disadvantages: life is sometimes “easier” if you don’t know (ex. Carrier parents of tay sachs need to decide if they want to risk having kids)
Bio - Unit 4 Notes
Body Systems
LESSON 1: Nutrients
DIGESTION: "The process of conversion of complex food particles into simplest forms by the action of Enzymes"
What is a Macromolecule?
= Large molecules (hundreds-thousands of atoms)
Living things are made of macromolecules – food is made of living things
4 main types of macromolecules:
Carbohydrates
Lipids
Proteins
Nucleic acids (DNA / RNA)
Different digestive tools/ mechanisms to break down different foods
Fill in the table below on different types of Macromolecules?
Macromolecule | Made of | Functions | Examples |
Carbohydrates |
|
|
|
Lipids |
|
|
|
Proteins |
|
|
|
Nucleic Acids |
|
|
|
Are natural sources of sugar (like honey) healthier to consume than artificial sources (like HFCS)?
No because they have other fake sugars such as corn syrup which are just as bad or worse
What are Trans Fats? Why are they now banned in Canada?
Processed foods → causes atherosclerosis
What are Vitamins and Minerals?
Micromolecules → elements (Ca, P, K, S, Mg, Cl, Na) and trace elements (Fe, I, Mn, Cu, Zn)
Responsible for supporting body processes
Ex. B12 helps with Iron absorption
Eat a balanced diet
2 Types:
Water-soluble → pee out extra (lose often)
Fat-soluble → stored in the fat in your body (lose rarely)
Can you overdose on Vitamins and Minerals?
Can help to take if deficient
Too much fat-soluble vitamins can be stored in your body and can overdose
Diet can also affect overdose (ex. Too much sodium = heart disease, stroke)
Why is digestion different in Autotrophs vs. Heterotrophs?
Heterotrophs need to get their food
Autotrophs make their own food
What are the steps of Digestion? (Name and description)
Ingestion → food in body (surrounded by body)
Plants make their own food → Photosynthesis
Heterotrophs/animals obtain food
Digestion → break down into small pieces
Mechanical or chemical digestion
Absorption → get nutrients and energy into cells (in body tissues – crossing cell membranes)
Transport of digested nutrients into tissues (usually via the circulatory system)
Egestion → waste products removed/ exit body
What are 3 different styles of Ingestion?
Filter feeding (water creatures) → engulf large bodies of water and strains out water and keeps food (ex. whales)
Fluid feeding → feeding off fluid from prey (ex. Mosquitoes drink blood from humans)
Gathering and feeding (ex. Mouths of cow, hands of human, elephant trunk)
What is mechanical digestion? Chemical digestion? How does chemical digestion occur?
Digestion = the obtained food must be broken down into more simple form
Mechanical digestion = physical breakdown of food (grinding, crushing, tearing, ripping)
Chemical digestion = Using chemicals/enzymes to break down chemical bonds in foods
2 types of products made:
Digested foods (simple nutrients)
Unnecessary waste products
Why are enzymes useful?
Are proteins that regulate the rate of chemical reactions (biological versions of catalysts)
Speed up chemical reactions
Do not get used up – can be used over again
Specific enzymes for each nutrient
What we eat depends on what enzymes we have (lock and key analogy)
Describe digestion in Amoeba.
Single-celled organism
Ingestion → no mouth, extend cell membrane (pseudopods) around food where ends fuse – to form a food vacuole
Digestion → Throws enzymes at food with lysosomes
Egestion → temporary opening for food to exit
Describe digestion in Hydra.
Ingestion → Poisonous tentacles shoves food in hole
Digestion → Tube contracts – mechanical breakdown
Absorption → Absorbed into cells – chemical breakdown
Egestion → back out the mouth
Describe digestion in Earthworms.
Complex digestion:
2 holes (one-way system)
In specialized organs, not in every cell
What seems to be the qualifiers to count as Simple vs Complex Digestion?
Simple digestion:
One hole
In every cell in the body
Complex digestion:
2 holes (one-way system)
In specialized organs, not in every cell
What is the major difference in the digestive systems of herbivores vs. carnivores? Why?
Carnivores = much shorter digestive system
Herbivores = longer large intestine since they have to digest cellulose (more time to break down) → specifically the caecum is enlarged since it has enzymes to break down cellulose
LESSON 2: Human Digestive System
ORGAN | STRUCTURE | FUNCTION | ENZYMES AND OTHER SUBSTANCES | |
Mouth | Tongue, Teeth (diff types for diff purposes), Incisors, Canines, Molars Salivary Glands Mechanical: Adult Teeth (32) Wisdom teeth (part of the 32) come in during high school, sometimes removed | Ingestion Teeth: Mechanically mash up food Saliva: Mucous = moisten food so it doesn’t damage your esophagus Enzyme amylase I = chemically digest carbs | Amylase I digests starch into glucose Mucous (not an enzyme) | |
Esophagus | Smooth involuntary muscle tube | Swallowing → smooth involuntary muscles contract in sequence – Peristalsis | ||
Stomach | Bag of multiple layers of muscle Lower Esophageal (cardiac) Sphincter = circular muscle that contracts (connecting esophagus to stomach) to ensure food travels one-way Pyloric Sphincter = stays firmly shut until stomach has chance to do its job | Storage → inflate and expand Mechanical digestion → Peristalsis Chemical digestion → break down proteins | Mucous lining = protecting against HCl Parietal Cell = HCl (starts to break proteins, kill bad bacteria, activate pepsinogen enzyme) Chief cells = Pepsinogen (not functional when made – only usable to break down protein once activated) HCl + Pepsinogen = Pepsin → break down protein | |
Small Intestine (30 ft) | Duodenum | Duodenum: short Jejunum & Ileum: 6-7 m long → folded Lined with epithelial tissue which have villi (big folds) and microvilli (microscopic folds on folds) Villi contain many blood vessels (capillaries) Villi are to increase surface area | Finish digesting the chyme from stomach, Calls on pancreas using hormone prosecretin (doesn’t work until in contact with HCl), then turns into secretin which gives signal for pancreas to send its chemicals | |
Jejunum | Absorption: Blood supply accepts sugars and amino acids. Lacteals (lymphatic system) accept fatty acids → which will eventually be absorbed into bloodstream | |||
Ileum | taking in nutrients Vitamin absorption | |||
Accessory Organs | Pancreas | Sends: bicarbonate (base) to neutralize HCl Enzymes: Amylase II (carbs) Erepsin (proteins) Lipase (fats) | ||
Liver | Produces bile (mechanical digestion of fat) → breaks it into fatty acids, filters blood supply | |||
Gallbladder | Storage of extra bile | |||
Large Intestine | Caecum + Appendix (accessory organ) | Wider in diameter and does not need as much surface area for absorption | Store good bacteria to help digest more → extra bacteria is stored in the appendix | |
Colon | Most water absorption (suck water out of poop)
| |||
Rectum |
Other Important Terms to Watch For:
Technical Term | What is it? |
Bolus | Food + Saliva |
Peristalsis | Smooth involuntary muscles contract in sequence |
Sphincter | Circular muscle that contracts to ensure food is pushed one way |
Chyme | Food + Saliva + HCl + Enzymes |
Lymph Nodes = store immune cells
Fluid has to run back through lymph nodes before leaked fluid in the Lymphatic system can come back into the body. If there is swelling → infection.
Fats are absorbed into the lymphatic system which will then go to the bloodstream
List All Steps of Digestion in Order (mechanical and chemical – including specific enzymes and organs) (don’t forget absorption and excretion of wastes) | ||
Breakdown of Carbs | Breakdown of Lipids (fats) | Breakdown of Proteins |
Label the Organs of the Digestive System
Label the Organs of the Digestive System Left Side (Match the diagram above) Right Side | |
LESSON 3: Probiotics (Microbiome)
Aka bacteria that already lives inside of you
Can survive stomach acid
What it does?
Out compete / keep away bad bacteria
Digest food
Modulate (adjust) immune system → creates a balance
Only want immune system to respond when necessary
Helps the immune system not respond to harmless stimuli (ex. Allergies)
Want to take probiotics when microbiome is disrupted
LESSON 4: Drugs & Digestion
The molecule / medicine is just the start
Need to understand how it will flow through the body
Methods → pills through mouth (swallowed or dissolved), injections, inhaled, skin absorption, suppositories through butt
If want to work quickly → want to be dissolved ealy in digestion
Need to shield drug from stomach acid, but then dissolve in the mild intestines
Many other factors affect how drugs will affect the body
Also, if you are physically fit → faster peristalsis for drugs to have a faster effect
Ex. Aspirin → blood thinner in order to prevent from blood clots
Has enzyme → COX-1 which blocks making mucous lining – can lead to ulcers and bleeding
Therefore if has the coating → the top coating will withstand the acidity of stomach and then the bottom coating is a base that will dissolve in the intestines
LESSON 5 - Respiratory System
KEY TERMS:
Respiration → all processes required to bring O2 into body cells (and release CO2)
Involves rib cage, diaphragm, nose, mouth, etc.
2 Requirements:
A large respiratory surface/membrane
Needs to be large because need enough O2
Surface area has to be moist → water has to dissolve CO2 and O2
Ex. Frogs are moist on their skin where they breathe
Ventilation → getting O2 across a respiratory surface (that does gas exchange)
Gas Exchange → the transfer of CO2 and O2 across cellular membranes
CO2 is constantly being made as a waste product of ATP → Need to get rid of it
Happens via diffusion since particles are so small
Nature always wants a balance of particles between membranes
Goes from high concentration from outside body and enters the low concentration in the cells → eventually reaches equilibrium
Respiratory Surface on Outside VS Inside:
Membrane on Inside | Membrane on Outside | |
Pros |
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Cons |
Need systems to:
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Examples | Humans, insects, rabbits, birds, fish |
Axolotl, frog |
Inside Respiratory System (Human):
There is space where gas exchange is not occurring
No breathing/ gas exchange happening on exhale
Different types of breathing:
Number of respiratory surfaces:
Humans have 1 respiratory surface → alveoli
Frogs have 3 respiratory surfaces → through their skin, lungs, mouth
Insects breathe through a series of holes (spiracles) along their body attached to tubes
Type of breathing:
Tidal breathing → gas exchange only on inhale – ex. humans
Unidirectional breathing → gas exchange twice on every breath – ex. Birds (allows them to fly due to the large energy expenditure)
Tidal and Unidirectional → Fish breathe through water → gill cover opens and water comes out operculular (holes)
Efficiency of gas exchange:
Will never extract all/most of O2 from air → only half can get in through diffusion (equilibrium)
Most animals & humans = Concurrent flow → water and blood continue to diffuse until equal (random directions) – blood flow and water flow goes in one direction, water will lose O2 and blood will gain, limits them to 50% of O2 exchange
Fish = Countercurrent flow → Blood vessels go one way, gills go the other way – allows them to maximize gas exchange
allows gills of fish to pick up most of O2 in water (90%)
Human Respiratory System:
Nasal cavity → have ridges (sinuses) to make the air swirl to filter, warm up and get moisture before reaching lungs – sinus cavities (spaces) fill up with mucous (can cause sinus infections when it does not drain properly)
Pharynx → connects nose and mouth cavity
Epiglottis (flap of skin at the end of pharynx) → closes when swallow to cover the trachea – when it misses, you will choke
Larynx → vocal chords – pieces of tissue that have muscles to shorten (high) and lengthen (low) them to change the pitch
Trachea → respiratory
Esophagus (behind trachea) → digestive system
Bronchi → moves air to gas exchange surface (lungs)
Bronchioles → smaller branches to get to alveoli
Alveoli → 1 cell thick, dead-end sacs surrounded by blood vessels for gas exchange
Diaphragm → underneath
GAS EXCHANGE
Both lungs have capillaries surrounding alveoli
Capillaries are never more than one cell away from each other
Exhale more H2O and CO2 than inhale, but also exhale O2
2 Types:
External Gas Exchange between lungs ←→ blood vessels
(O2 →) (← CO2)
Internal Gas Exchange between blood vessels ←→ body cells
(O2 →) (← CO2)
Transport in Blood:
Oxygen Transport:
Mostly carried by Hb in RBC’s
Dissolves in blood – O2 (aq)
CO2 Transport:
Dissolves in blood – CO2 (aq)
Attaches to Hb in RBC’s
Carried by bicarbonate in blood – CO2 + H2O ←→ Carbonic Acid (H2CO3) ←→ HCO3- + H+
As more CO2 is taken up by the blood, the blood increases in acidity = causing BR to increase
Blood too acidic or too basic → die
Blood Ph needs to exist between 7.2-7.4
BR will continue to increase and decrease based on controlling acidity in the blood
Mechanics of Breathing:
Have to create enough empty space in chest → air will rush in to fill that space
Muscles along diaphragm and in between ribs (intercostal muscles)
Inhale (Inspiration):
Ribs move up and out
Diaphragm contracts down
Increased the volume of chest cavity → creating low pressure → air rushes in to fill the void in lungs
Takes more energy since contracting muscles
Exhale (Expiration):
Ribs go down
Diaphragm goes up
Decreasing volume of chest cavity → higher pressure → air gets pushed out of lungs
Takes less energy since relaxing muscles
Pressure and volume have an inverse relationship – when up the other down (vise versa)
Controlling Breathing:
Oxygen sensor → Aorta – constantly checking on breathing rate
If BR is too low, sends a message to brain which sends to diaphragm and intercostal muscles to contract
Medulla (brainstem) sensor → having a sensor that constantly checking blood Ph (CO2 sensor) and most important structure in entire body
Carotid body → Carotid Artery – body sensor (O2 and CO2 sensor)
Tracking Breathing:
Speromater → tracks inspiration and expiration in breathing
Tidal Volume (TV) → Normal inhale and exhale
Functional Vital Capacity (FVC) → the maximum amount of air inhaled and exhaled
Residual Lung Volume (RLV) → You can never exhale all the O2 out of lungs – Lungs will stick to themselves if all the O2 is exhaled out of their lungs
Respiratory Disorders:
Restricted breathing → a hard time fully expanding your lungs (something wrong with chest cavity, can occur when tissue in chest wall becomes stiffened or due to weakened muscles or damaged nerves)
Obstructive breathing → narrowing of airways hinder a person’s ability to expel air (something wrong with tubes – makes activity harder)
Examples:
Asthma → airway tube gets smaller and muscle surrounding bronchioles constricts
COPD → bronchitis (mucous build up in the walls) and emphysema together
Emphysema → walls of alveoli break – not much surface area and gas exchange
Smoking:
Healthy lungs = pink
Tar filled lungs = black
Smoking breaks down alveoli walls → COPD, Emphysema
However does not feel like can’t breathe as well as nicotine allows your alveoli walls to open
Can recover from damage eventually
Vaping:
No tar in it
Was meant to be a transitional device for cigarette smokers
Has all the same effects as smoking, just less
Long term → can lead to emphysema or COPD
Heart → increased atherosclerosis, BP, HR
Air Pollution:
PM – smaller the particulate matter, the deeper it can get into the lungs
Ex. methane, carbon monoxide, fossil fuels, nitrogen oxide
Respiratory problems → asthma
Children → still developing (lungs are growing/ changing), BR 2x as much as adults (bc need more O2 and smaller lungs)
High Altitude Breathing:
Big strain on respiratory and circulatory systems
At ground level there is a larger amount of O2, but as you go higher, less O2 available → due to gravity
When less O2 in higher altitude → BR & HR increases (hyperventilating), sleep less, urinate more
Blood becomes thicker, body starts making more RBC’s after a few days → acclimatization (body adjusting to the climate)
Altitude training:
Train where you get the benefits of more RBC and arrive at the event the day before
Blood doping → taking out blood at high altitude and give yourself blood transfusion before your events
Pros:
More RBCs
Enhanced O2 transport
Increased endurance
Cons:
Dehydration
Stress
Lack of iron
Carbon Monoxide Poisoning:
Hb loves CO
RBCs will preferentially pick up CO, even if O2 is available
“Silent Killer”
CO is invisible to sense and about the same density of air
fatigue, H/A, nausea – no alarming symptoms other than dizziness and chest tightness
CO is a result of incomplete combustion → found in furnace in house
CO detectors / alarms are a law to have in houses since 2014 – changes to a new chemical that sets off an alarm
Circulatory System:
Main functions:
Transport
O2/CO2
Components of the immune system
Wastes
Hormones
Components needed for repair
Transports everything
Helps to regulate body temperature as well
Single Celled Organisms:
No specialized/true circulatory system
Undergoes cytoplasmic streaming - circulates fluid within the cell
Equivalent of using a squeeze bottle
3 parts of circulatory systems in multicellular organisms:
Fluids,
Tubes and vessels
Pump
Different types of circulatory systems:
Open - fluid pumped out of tubes into body cavity, tubes are open to the body cavity
A few tubes connected to the pump and then blood flows freely throughout the body eventually reaching the tubes again
Low energy and efficient, but have to be small (insects)
Closed - closed complete circuit of blood vessels - blood always gets where it needs to go
Much more efficient at getting stuff where it needs to go, far harder to set up, need to build way more blood vessels, if one pops it must be repaired
Blood stays in blood vessels
Tubes connected to pumps - no breaks
Very efficient but need lots of blood vessels (high energy)
Open System - 90% of animals
Circuit of vessels is incomplete
Not efficient enough to support a large animal, but is in all insects
Most typical animals are all closed, but that is a very small percentage of all animals
Fluids (not blood) pour from vessels into body cavity and back
Eventually goes back to heart and gets recirculated but not very efficient
Benefit: doesn’t require a lot of building material or repair, less effort in construction and repair of blood vessels, less energy to create and maintain
Pumping action returns fluids to the heart
No oxygen carrying molecules
Works good enough for insects
Closed system
Circulatory vessels make a complete circuit
Fluids stay in the vessels where they are supposed to be, always get where they need to be
Circulatory Structures (Blood Vessels):
Heart
Have chambers → collecting blood (atrium) & pumping blood (ventricle)
Elastic Artery (high pressure)
smaller internal diameter
thicker muscular walls
Carries O2 blood from heart to body
Arterioles (smaller tube)
Capillaries (walls = 1 cell thick) → gas exchange
Surround every cell in the body
Venules
Veins (low pressure) →
wider internal diameter
thinner walls
Have one-way valves – prevent backflow
Carries d-O2 blood back to heart
Back into heart
With every beat of the heart → the valves pushes the blood through the veins
Varicose Veins → Blood pools within the valves and is not properly pushed through the valves (can see bulges on outside – typically lower leg)
Can cause blood clots → DVT
To fix it → compression socks, heat (catheter), inject to collapse veins
Spider Veins → not harmful, purple in colour, veins ripped slightly
Blood Composition:
½ Plasma → water, ions, nutrients, gases, wastes (anything dissolved in liquid)
½ Solids → Mostly RBCs – carry O2 and CO2
Have no nucleus, time limited → will live as long as possible and then get recycled because there are no instructions to make more (no mitosis)
Made in bone marrow
→ WBCs (Immune system & large) and Platelets (clotting & tiny – acts like webs)
Also made in the bone marrow
Heart Comparative Anatomy:
Fish → 1 atrium, 1 ventricle – d-O2 blood go to capillaries, picks up O2 (becomes O2 blood), delivers it to the body, then returns d-O2 blood back to atrium
Frog → 2 atriums, 1 ventricle
D-O2 enters 1 atrium, goes to ventricle, goes to lungs (gas exchange), O2 blood back to ventricle, pumped to rest of body
Errors: d-O2 and O2 blood mix in the ventricle
d-O2 blood can get sent back to body
O2 blood can get sent back to lungs
Human Circulation:
Pulmonary Circuit = heart ←→ lungs
Systemic Circuit = heart ←→ body
Cardiac Circuit = heart ←→ heart muscle
Heart attack occurs in this circulation
LESSON 2 - The Human Heart Anatomy:
Made of cardiac muscle
Valves open and close with the beating of the heart
Right side → d-O2 blood sent to lungs
Right ventricle thin muscle wall compared to left
Left side → O2 blood sent to body
Right Side:
Start by collecting d-O2 blood from superior and inferior vena cava
Then empties in the right atrium (collecting chamber)
Tricuspid (3 flaps) valve (ensure one-way)
Blood goes to right ventricle (pumping chamber) which contracts
Pulmonary semilunar valve
Pulmonary arteries to lungs to get O2
Left Side:
O2 blood comes back to heart by pulmonary veins
Blood empties into left atrium
Goes through mitral / bicuspid valve (2 flaps)
Left ventricle → thick muscular wall that pumps the oxygenated blood to your entire body
Aortic semilunar valve
Blood now moves through Aorta → biggest, highest pressure artery in the body, giant curved blood vessel
Pumps upward to neck and head, rest follows the curve down and runs down the spine and into the abdomen and then both legs through abdominal aorta
Instant death if this breaks
Heart Beat:
Closing of the valves creates heartbeat noise (aortic and pulmonary closing together, tricuspid and bicuspid closing together) - 2 beat noises
“Lub-Dub” = word for heartbeat sound
Atriums refill ventricles, pause, ventricles refire
2 sounds, 4 valves → 2 will always close at the same time
Heart murmur = what docs listen for when listening to valves
Listening for a whoosh sound
Means valve is stiff or leaking
LESSON 3 - The Electrical System:
Heart runs independently since it has its own electrical NS with 4 parts
Sinoatrial (SA) node
Specialized cells that generate electricity and sends signal to atriums to contract
Pacemaker → decides on pace of heart pumping – send signal to both atriums independently from brain
Also sends signal to AV nodes
Atrioventricular (AV) node
Connecting atrium to ventricle
Recieves SA signal but waits → has a time delay for everything not to contract at once
Sends signal down septum (Bundle of HIS - nerve fibres) of heart, separates at the bottom of both ventricles (purkinje fibres) and tells ventricles to contract bottom up
Bundle of HIS
Purkinje Fibres
Ensure ventricles contract from bottom up
ECG - Electrocardiogram:
1 heart beat
P wave → SA node signal (little bump)
Atriums contract
Q wave → (little dip)
R wave → atriums relax (large bump)
S wave → (little bump)
QRS = AV node signal
Ventricles contract
T wave → reset heart electrical system –put + and - ions back where they started– and ventricles relax
Reading ECG:
Vertical boxes = electricity
Each box = 1 mV
Horizontal boxes = time
Each box = 0.04 sec
Things that go wrong:
Fast heartbeat = as ventricles relaxing, atriums are already contracting → T and P wave overlapping
Slow heartbeat = interval between heartbeats is longer
Irregular heartbeat = inconsistent intervals (fast and slow combined)
Examples:
Tachycardia → fast heartbeat
Myocardial infarction → Ventricles not contracting – S wave not working
Extrasystole → premature / extra heart beat
Ventricular fibrillation → heart barely contracting – needs to be restarted
Complete heart block → SA and AV nodes not communicating / working together
Pacemaker = when SA node does not work properly
LESSON 4 - Blood Pressure
Monitors circulation → the pressure at which blood pushes on the blood vessels
Excellent determinant of cardiovascular health
Regular BP = 120/80 or 115/75 mmHg systolic
High BP can cause: heart attack, stroke, H/A, elevated BS, eye problems, kidney failure
Systolic Pressure:
Top number of BP → should be around 115 mm
Ventricles contract → blood getting pushed through arteries
Diastolic Pressure:
Bottom number BP → should be around 75 mm
Ventricles relax → atriums contract
How to take BP:
Put sphygmomanometer around brachial artery (around underneath armpit)
Find pulse around elbow area
Take the stethoscope and place the ears facing forward
Inflate until around 140 → past systolic
Release the knob slightly and put stethoscope on elbow
Artery goes from open (heart pushes blood) to compressed shut in high pressure → every time heart beats force opens, relaxes – cuff forces it shut making thud sound
Stop hearing sound during diastolic because artery will not shut
14 x 6 = 84 bpm → normal = 60-80 bpm at rest
17 → right after standing up
16 → standing
Baroreceptor Reflex:
In aorta, baroreceptor detects drop in pressure (measuring BP) → signals sent to the medulla → tells SA node to work
When standing up immediately BP drops, but body panics and momentary spikes BP and pulse (reflex), then drops back to normal (to not pass out)
Cardiac Output:
= Blood out of heart / min
Need to know:
Heart rate (bpm) x stroke volume (mL/beat) → how much fluid moving per beat
Stroke volume avg = 70 mL
Heart rate avg = 60-80 bpm
70 beats/min x 70 mL/beat = 4900 mL/min (4.9 L / min)
When exercising → can increase heart rate by 7x (35 L / min)
Factors affecting HR:
Hormones
Fitness levels
Age
Genetics
Factors affecting SV:
Heart size
Gender
Fitness
Genetics
Examples:
Person A = 70 bpm, 70 SV, CO = 4900 mL → normal
Person B = 85 bpm, 35 SV, CO = 3000 mL → in trouble / hospital
Person C = 40 bpm, 125 SV, CO = 5000 mL → athlete
Person D = 80 bpm, 62 SV, CO = 5000 mL → couch potato
Person E = 200 bpm, 150 SV, CO = 30,000 mL → exercising now
Cardiovascular System Diseases:
Vessels:
| Heart:
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Blood:
| Electrical:
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