Bio - Unit 1 Notes

Biodiversity

LESSON 1 - Intro to Diversity

1. 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)

2. 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

3. 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:

1. Bacteria

2. Archaea

3. 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: 

1. Genus (Capitalized)

2. 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?

1. Morphology → similar shape, size, structure (do they look similar)

• Not the best/most accurate

2. 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 

3. 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

1. How much DNA in common

2. Anatomy – what body looks like

3. 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

1. 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

2. Archaebacteria

• Live in extreme environment (volcano, zero oxygen, pool of arsenic)

• Have a cell wall (not made of peptidoglycan)

3. Protists 

• Most are single celled, some are multi-celled (exp. kelp/algae

• Some have a cell wall

• Can be autotrophic, heterotrophic or both

4. Fungi

• Multicellular

• Eukaryotic

• Heterotrophic

• Reproduce sexually and asexually

• Have a cell wall – Chitin (used for dissolving stitches)

• Terrestrial 

5. 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

6. Animals

• Multicellular

• Eukaryotic

• Most reproduce sexually

• Heterotrophic

• Live in terrestrial and aquatic habitats

Who am I Questions *** on test

Kingdom Animalia Key Features:

1. Organization → whether you have tissues (specialized cells to do something) or not

• Classification = cell → tissue → organs → organ system → organism

• Ex. sea sponge

2. Symmetry → two parts are the same when split

• Radial symmetry = symmetrical all around

• Bilateral symmetry = 2 sided symmetry on outside

• Ex. jellyfish

3. 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

4. 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?

1. Bacteria affects the environment

• Decomposers, food spoilage, cyanobacteria (oxygen), disease

2. Archaea are used for industry

• DNA testing relies on enzymes that can survive at 70+ degrees celsius, diagnosing diseases, intestinal issues

3. Viruses

• Prevention of disease, genetic engineering

• 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

Examples of Human Viruses:

• Flu

• Cold

• Herpes or cold sores

• Measles

What does it mean to be living?

1. Growth and development

2. Energy metabolism 

3. Homeostasis

4. Adaptation as a species

5. Response to stimuli (things in external environment – movement and adaptation over a period of time)

6. Cells

7. 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:

1. DNA/RNA – code of just what the virus does

2. Surrounded by a membrane – in a protein coat (capsid)

3. Spikes = keys → spike has to match the receptors part of the host cell to get in (part that changes the most)

4. 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)

1. Phage attaches to the cell → spikes must match up with host

2. Phage DNA enters the cell

3. Hijacking = Host DNA now has a new instruction manual → host DNA breaks up

4. New virus cell forms 

5. 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

1. Attachment

2. Insert DNA

3. DNA merges and becomes part of the host DNA

4. When cells replicate → copy both virus and cell DNA

5. 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:

1. Who survives to maturity

2. 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:

1. Directional Selection → where ONE extreme is favoured and the variation frequency continues to shift in one direction (ex. The moths)

2. Disruptive Selection → where BOTH extremes are favoured and they both continue to survive in different ways 

3. 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:

1. 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

2. 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 

3. 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):

1. 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)

2. 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

3. Middle finger → Mutation → The changing of the structure of a gene, resulting in a new variation

• Ex. Some humans are born without wisdom teeth

4. 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

5. 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:

1. Trying to assert dominance → Intrasexual selection (within one gender)

• Women typically go for looks and men go for physical damage

2. 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:

1. Gradualism = species that gradually/slowly get more different

2. 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:

1. Pre-zygotic → prevent from making a zygote (first cell with sperm and egg not coming together)

1. Habitat Isolation → if don’t live in the same spot, won’t mate (same geographic area yet separate or different habitat)

2. Temporal Isolation → reproductive cycles for mating occurs at different times (day vs night / seasonal)

3. 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

4. Mechanical Isolation → structural differences in reproductive organs (the parts don’t fit)

5. 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)

2. Post-zygotic → prevent zygote/hybrid offspring from reproducing (sperm and egg come together but prevent from having baby)

1. Zygote Mortality → Initial cell formed upon fertilization dies

• Genetics, mom cannot carry, chemically not compatible enough

2. 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)

3. Hybrid Infertility → Offspring strong/fit and adults are healthy, yet are sterile (can’t reproduce)

• Ex. Mules and Ligers

4. 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

1. 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

2. 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 

3. 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

4. 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

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

1. Summarize the relationship between genes & DNA

• Genes are a section of the DNA which code for a specific trait/protein

2. Describe the overall structure of the DNA molecule

• Double helix – connected by 

• Ladder shape

• Nucleotide = phosphate, sugar, nitrogenous base (ACTG)

3. 4 kinds of bases 

NAMING DNA

LESSON 2 - Mitosis

1. The cell cycle includes what 3 phases?   What happens in each phase?

1. Interphase (pre-mitosis)

   • Before mitosis 

   • The cell does normal cell activities (making cell proteins)

   • What the cell does majority of its life 

   • DNA replication

2. Mitosis (only 4 stages during the cell division process)

• Prophase 

• Metaphase 

• Anaphase 

• Telophase 

• Moving the DNA around

3. Cytokinesis (post cell division)

• The splitting of the cells

2. What is DNA called when it is…

   1. Uncoiled? 

• Chromatin 

2. Coiled up?

• Chromosome 

3. An exact duplicate half of a chromosome?

• Sister chromatids 

3. How many different pieces of DNA do human cells have?

• 46 (23 from each parent)

4. 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 

5. What do we call the resulting new cells at the end of Mitosis?

2 daughter cells

6. What are the 4 phases of mitosis?  

7. 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

8. 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

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 

1. IA = A antigen on RBC (IAIA , IAi)

2. IB = B antigen on RBC (IBIB, IBi)

3. i/ O = neither A or B antigen (ii)

4. AB = both A and B antigen (IAIB)

• 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:

1. 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 

2. 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

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

1. Colour blind man x woman carrier

2. 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:

1. Difference between a Punnett square and a Pedigree

• Punnett = predicting offspring 

• Pedigree = looking at family traits, pattern of inheritance

2. 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

3. Why might factors, such as food choices, pollution, smoking not have the same effect on all people? 

• Answer in Q2

4. 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"

1. 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: 

1. Carbohydrates

2. Lipids

3. Proteins

4. Nucleic acids (DNA / RNA)

• Different digestive tools/ mechanisms to break down different foods

2. Fill in the table below on different types of Macromolecules?

3. 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 

4. What are Trans Fats?  Why are they now banned in Canada?

• Processed foods → causes atherosclerosis 

5. 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)

6. 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)

7. Why is digestion different in Autotrophs vs. Heterotrophs?

• Heterotrophs need to get their food

• Autotrophs make their own food 

8. What are the steps of Digestion? (Name and description)

1. Ingestion → food in body (surrounded by body)

• Plants make their own food → Photosynthesis

• Heterotrophs/animals obtain food

2. Digestion → break down into small pieces

• Mechanical or chemical digestion

3. Absorption → get nutrients and energy into cells (in body tissues – crossing cell membranes)

• Transport of digested nutrients into tissues (usually via the circulatory system)

4. Egestion → waste products removed/ exit body

9. What are 3 different styles of Ingestion?

1. Filter feeding (water creatures) → engulf large bodies of water and strains out water and keeps food (ex. whales)

2. Fluid feeding → feeding off fluid from prey (ex. Mosquitoes drink blood from humans)

3. Gathering and feeding (ex. Mouths of cow, hands of human, elephant trunk)

10. 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:

1. Digested foods (simple nutrients)

2. Unnecessary waste products 

11. 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)

12. 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

13. 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

14. Describe digestion in Earthworms. 

Complex digestion:

• 2 holes (one-way system)

• In specialized organs, not in every cell

15. 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

16. 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

Other Important Terms to Watch For:

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 

Label the Organs of the Digestive System

LESSON 3: Probiotics (Microbiome)

• Aka bacteria that already lives inside of you

• Can survive stomach acid

What it does?

1. Out compete / keep away bad bacteria

2. Digest food 

3. 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:

1. A large respiratory surface/membrane

• Needs to be large because need enough O2 

2. 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:

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:

1. 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)

2. Pharynx → connects nose and mouth cavity

3. Epiglottis (flap of skin at the end of pharynx) → closes when swallow to cover the trachea – when it misses, you will choke 

4. Larynx → vocal chords – pieces of tissue that have muscles to shorten (high) and lengthen (low) them to change the pitch 

5. Trachea → respiratory

6. Esophagus (behind trachea) → digestive system 

7. Bronchi → moves air to gas exchange surface (lungs)

8. Bronchioles → smaller branches to get to alveoli

9. Alveoli → 1 cell thick, dead-end sacs surrounded by blood vessels for gas exchange

10. 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:

1. External Gas Exchange between lungs ←→ blood vessels 

      (O2 →) (← CO2)

2. Internal Gas Exchange between blood vessels ←→ body cells

     (O2 →) (← CO2) 

Transport in Blood:

Oxygen Transport:

1. Mostly carried by Hb in RBC’s 

2. Dissolves in blood – O2 (aq)

CO2 Transport:

1. Dissolves in blood – CO2 (aq)

2. Attaches to Hb in RBC’s 

3. 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:

1. 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

2. Medulla (brainstem) sensor → having a sensor that constantly checking blood Ph (CO2 sensor) and most important structure in entire body

3. 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” 

1. CO is invisible to sense and about the same density of air

2. 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:

1. Fluids, 

2. Tubes and vessels 

3. Pump

Different types of circulatory systems:

1. 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)

2. 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):

1. Heart

• Have chambers → collecting blood (atrium) & pumping blood (ventricle)

2. Elastic Artery (high pressure) 

• smaller internal diameter

• thicker muscular walls

• Carries O2 blood from heart to body

3. Arterioles (smaller tube)

4. Capillaries (walls = 1 cell thick) → gas exchange

• Surround every cell in the body

5. Venules

6. Veins (low pressure) → 

• wider internal diameter

• thinner walls 

• Have one-way valves – prevent backflow 

• Carries d-O2 blood back to heart

7. 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:

1. 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

2. 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:

1. Pulmonary Circuit = heart ←→ lungs

2. Systemic Circuit = heart ←→ body

3. 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

1. 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

2. 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

3. Bundle of HIS

4. 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: