Biology Review

Differentiate monosomy and trisomy disorders

Monosomy	Similarities	Trisomy
When there is only 1 chromosome present in what’s supposed to be a  pair	Both are a product of nondisjunction, where a chromosome detaches from a spindle fibre improperly, causing there to be one more or less chromatid in a cell.	When there are 3 chromosomes present in what’s supposed to be a pair

homozygous and heterozygous genotypes

Homozygous	When the two alleles are both dominant or both recessive.
Heterozygous	When there is a dominant and recessive allele shown in the genotype.

Types of Dominance

Complete Dominance	When the dominant allele completely overshadows the recessive allele and is the only one physically represented. Or, when the only alleles present are the recessive ones.
Incomplete Dominance	When the two alleles that are present are both shown as a mix (ex. a mix of both colours, a middle ground of two sizes)
Codominance	When the two alleles that are present are both shown physically, individually (ex. spots of both colours, both textures of fur)

Monohybrid Cross

(Single Trait Cross):

Dihybrid Cross

Two Traits Cross

Using a karytoype to know sex & Disorders

• Females have two X chromosomes (XX).

• Males have one X and one Y chromosome (XY).

• Disorders Identified by Karyotypes:

Down Syndrome (Trisomy 21): The individual has three copies of chromosome 21 instead of the usual two.

Differentiate constipation and diarrhea

Constipation	Diarrhea
Too much water is absorbed	Too little water is absorbed

• Identify the importance of goblet cells, cilia, diffusion and homeostasis in respiration

Goblet Cells	Similarities	Cilia
Mucus producing cells Mucus moistens and traps dust and debris in the air	Both aid the respiratory system in getting rid of foreign objects or bacteria out of the lungs and out of the mouth

Diffusion and homeostasis are important in respiration because the diffusion of oxygen into the bloodstream is crucial to staying alive. Oxygen is brought through the bloodstream to the tissues of the body, which then are diffused into the cells of the tissue which create energy through the mitochondria to make ATP/energy for the body. Homeostasis is important because it is the body regulating itself, monitoring to see if the body needs to increase breathing rate, heart rate, and volume of inhalation to remove excess carbon dioxide.

Label lung capacity chart to identify IRV,TV, VC, ERV or RV values

Differentiate internal and external respiration

Internal Respiration	Similarities	External Respiration
Gas exchange between the bloodstream and the cells of the body	Both are the diffusion of oxygen and carbon dioxide to different levels of concentration in the respiratory system.	Gas exchange between alveoli and the bloodstream

Describe the function of blood and all of its components  (including labeling a hematocrit tube

Plasma	A protein-rich liquid that suspends the cellular components of blood (mainly water)
Leukocytes	Granular Originate from bone marrow Engulf foreign particles  Produce pus when they die Part of the innate immune system (something we are born with)  Agranular Originate from the thymus gland Do not engulf  Part of the acquired immune system (something we develop over time)  2 types: B cells and T cells
Platelets	Small fragments of cells that are responsible for clotting (coagulation of blood)
Erythrocytes	Biconcave in shape to maximize surface area No nucleus or mitochondria Contains roughly 240 million hemoglobin molecules  Carries O2 and CO2 between the lungs and the tissues

Label and identify the pathway of blood through the heart***

The Pulmonary Circuit:

1. Deoxygenated blood from the body returns to the heart via the superior and inferior vena cava into the right atrium

2. Blood then flows through the tricuspid valve and into the right ventricle

3. The right ventricle contracts sending blood through the pulmonary valve and out of the heart through the left and right pulmonary arteries

4. The deoxygenated blood then enters the lungs where it picks up oxygen and releases carbon dioxide

The Systemic Circuit:

1. The oxygenated blood then returns to the heart’s left atrium via the right and left pulmonary veins

2. It then passes through the mitral valve and enters the left ventricle

3. The left ventricle then contracts and blood is forced through the aortic valve into the aorta

It then enters the systemic circuit. Here the blood will pass through capillaries and gas exchanges will occur so that oxygen and nutrients can enter our cells.

The Coronary Circuit:

The heart muscle also needs nutrients and oxygen. Blood is delivered to the heart through the coronary circuit. 

Consists of: 

• Left coronary artery

• Right coronary artery

• Label and differentiate euglena and paramecium**

Paramecium 

This is a heterotrophic, animal-like protist in the ciliates group. 

Cilia	aid in small movement
Oral Groove and Gullet	help bring food in which turns into food vacuole
Food Vacuoles	meals are digested here
Contractile Vacuole	eliminates excess water

*Euglena 

This is a photosynthesis , plant-like protists in the euglenoid group.

 

Chloroplast	carry out photosynthesis
Eye spot	used to detect light
Flagellum	aid in major movement
Pellicle	stiff but flexible layer that gives structure but the euglena still can change shape

• Identify the name bacteria based on arrangement and morphology*

Arrangement	Prefix name		Morphology	Singular (suffix)	Plural (suffix)
Single	N/A		Spherical	cocus	cocci

In pairs	diplo		Rod shaped	bacillus	bacilli
Clusters	staphylo		Spiral	spirillum	spirilla
Chains	strepto		Ex. Staphylococcus aureus  Prefix - “staphylo” = clusters  Suffix - “coccus” = spherical

dentify the domain and kingdom of an organism based on characteristics and properties (ex. presence of cell wall, heterotrophic vs autotrophic, etc. )

Domain	Kingdom	Type of Cell? (Prokaryotic or Eukaryotic)	Single or Multicellular or Both	Autotroph or Heterotroph or Both	Reproduce sexually or asexually? (specifically to increase population size)	Cell Wall material	Examples
Bacteria	Eubacteria	Prokaryotic	single	both	asexually (through binary fission)	pepto glycogen	Staphylococcus
Archaea	Archaea	Prokaryotic	single	both	asexually	no pepto glycogen	Extreme thermophiles
Eukarya	Protist	Eukaryotic	both	both	both	some have cellulose most= no cell wall	Amoeba, euglena
Eukarya	Plant	Eukaryotic	multicellular	Autotroph	sexually	cellulose	Tulips, Ferns, Pine trees
Eukarya	Fungi	Eukaryotic	most are multicellular	Heterotroph	sexually	chitin	Mushroom, bread molds
Eukarya	Animals	Eukaryotic	multicellular	Heterotroph	sexually	n/a	Rabbit, Lion

Define biological classification and taxonomy and list taxonomic levels in order**

Biological classification is the systematic grouping of organisms into biological categories based on physical  and evolutionary relationships.

Taxonomy is the science of classifying all organisms including both living and fossil species

Domain, kingodom, phylum, Class, order, family, genus, species

Identify and describe the symptoms, treatment, diagnosis of malaria  and athlete's foot **

What is Malara	Symptoms	Diagnosis	Treatment
Caused by the parasitic infection of Plasmodium that is transmitted to humans by mosquitoes.  Majority of cases occur in Africa and South Asia  due to the warm climate. Children, seniors and pregnant women are most at risk of dying	fever and sweating chills that shake your whole body Fatigue  Chest pain Issues Breathing Cough Diarrhea  Nausea Vomiting	Blood Test:  A blood sample will detect the presence of the Plasmodium parasite	Medication:  medication can begin to work to kill malaria in early stages  Some Plasmodium have develop resistance to medication  Many undesirable side effects such as seizures, insomnia, headaches and vision issues,

What is Athlete's Foot	Symptoms	Diagnosis	Treatment
A fungal infection caused by the ringworm fungus.  Often affects people with sweaty feet or contact with fungus-affected surfaces.	Scaly, peeling or cracking skin between toes itchiness , especially right after taking off shoes and socks Inflamed skin that might appear discolored  Burning or stinging Blistering Dry, scaly skin on the bottom of the foot that extends up the side	Skin Test:  A sample of skin can be sent to lab to confirm the presence of ringworm	Medication:  Medicated creams that contain antifungal chemicals can help to kill fungus Fungal infections are normally persistent so medication will need to be applied daily , consistently for the most success.  oral medication may be needed for severe cases.

Differentiate radial and bilateral symmetry as well as deuterostomes and protostomes

Radial Symmetry	Similarities	Bilateral Symmetry
Symmetry around a central axis	This change occurs after the second division of animal Both have to do with symmetry and divide the type of animals.	Symmetry around a midline

Deuterostomes	Similarities	Protostomes
When the anus forms before the mouth during embryonic development	The formation of the anus as an embryo	When the mouth forms before the anus during embryonic development

Describe lytic and lysogenic cycle

Lysogenic cycle: 

This is when the virus stays in the dormant state but each time the host cell replicates, it replicates the viral DNA as well; however when the host cell encounters stress, viral DNA activates and enters the lytic cycle. 

Step 1	Attachment : virus binds to surface of host cell
Step 2	Insertion : virus DNA enters host

Examples of stress: 

• Change in temperature 

• Introduction of new chemical or  hormone 

• Change in  pH

• Change in nutrient availability  

During this stage the host is considered asymptomatic.

Lytic cycle:  This is when the host cell bursts and releases new viruses into the host. During this stage the host would experience symptoms .	Step 5	Replication : host cell DNA is destroyed and it is forced to  make viral DNA/RNA and proteins
	Step 6	Assembly: new viruses are made inside of the host cell
	Step 7	Lyses: the cell bursts and releases virus particles

• Differentiate evidence of fossils, anatomy, embryology, biogeography and DNA**

Fossils	Fossils are any ancient remains, impressions or traces of an organism or traces of its activity that have been preserved in rocks or other mineral deposits in Earth’s crust. Requires at least 10K years.
Anatomy	If all living things are related to each other but evolved over time, then we should expect to find evidence for these relationships by examining their anatomy.
Embryology	Embryology is the scientific study of the early developmental stages of life. This field of science has confirmed the relationship between many organisms.
Biogeography	Biogeography is the scientific study of the geographical distribution of organisms based on both living species and fossils.
DNA	Nowadays we can trace the similarity between species by looking at their genetic code. The degree of similarity between homologous genes provides good evidence for the degree of relatedness between species.

• Explain how natural selection occurs in different scenarios

Variation	For natural selection to occur, a population must exhibit phenotypic differences.
Heritability	Parents must be able to pass on the traits to their offspring. If the variation dies within one generation then it doesn’t allow evolution to occur.
Competition	There must be some level of competition in order to have “survival of the fittest” competition can be within the same species or between different species.

• Identify the difference between directional, stabilizing, disruptive and sexual selection**

Directional	This occurs when selection favors individuals with a more extreme variation of a trait and shifts away from the average.
Stabilizing	This occurs when the environment favours the average phenotype and selects against individuals with extreme traits.
Disruptive	This occurs when the environment favours individuals with opposite extremes of the trait.
Sexual	This type selection is one that favors any trait that specifically enhances the mating success of an individual. Sexual selection often leads to the males and females of a species evolving appearance and behaviors that are quite different from each other.

Explain artificial and sexual selection

Artificial Selection	Similarities	Sexual Selection
Artificial selection is where selection is dictated by humans. Typically if individuals in a population exhibit a particular trait that is desirable and they are bred to amplify the trait that suits our needs. This is made possible through the domestication of both plants and animals.	Both have disadvantageous sides to them, as they both would decrease the amount of reproductive success.	This type selection is one that favors any trait that specifically enhances the mating success of an individual. Sexual selection often leads to the males and females of a species evolving appearance and behaviors that are quite different from each other.

Identify the various types of reproductive isolating mechanisms especially when presented with a scenario***

Prezygotic Barriers: are mechanisms that prevent successful mating and fertilized of an egg

Postzygotic Barriers: are mechanisms that prevent a fertilized egg from growing into a viable  and reproductive  adult. 

Mechanism	Description	Example
Prezygotic - Preventative Mating
Behavioral Isolation	don’t respond to eachothers mating rituals	Male Grey Crickets rub their wings 25 times per second while Black Crickets rub their wings 45 times per second. Females only respond to sound made by males of the same species
Temporal Isolation	breed at different times of the year	The Wood Frog and Leopard Frog are available for mating (in heat) almost a month apart from one another
Habitual Isolation	occupy 2 different habitats in the same region	The Northwest Garter Snake prefers open areas and the Common Garter Snake is typically found in the water.
Prezygotic - Preventative Fertilization
Mechanical Isolation	size and/or shape of reproductive organns	Many male and female insects have uniquely shaped exoskeletons that fit each other  perfectly “lock and key” making them incompatible with other species.
Gametic Isolation	sperm and eggs can’t recognize eachother	Many marine animals such as giant clams, dolphins and whales release their sperm into open water. Sperm recognize eggs through chemical markers on the surface of the eggs.

What is a Hybrid?

A hybrid is a cross between two different species. This is fairly common in plants and happens naturally. 

This is less common in animals and often results from genetic engineering   and or artificial insemination. 

Mechanism	Description	Example
Postzygotic - Preventative Hybrids
Hybrid Inviability	known as zygotic mortality, hybrid embryos die early in development before birth	The embryos of sheeps and goats die early in development before birth and are deemed a miscarriage.
Hybrid Sterility/Infertility	mating between 2 species resulting in infertile offspring	When a donkey is crossed with a horse it produces a Mule which is sterile and therefore unable to reproduce.
Hybrid Breakdown	first gen of hybrids may be fertile but successive generations with become weak and die in development	In different species of cotton plants, the offspring of hybrids die in early development

Identify the patterns of evolution especially when presented with a scenario***

Adaptive Radiation: 

A single species evolves into multiple closely related species, each adapted to different environments or resources, showing subtle differences

.Example: 

The most famous of Darwin’s observations were on the Galapagos Islands (a group of 18 islands that formed off the coast of South America from volcanoes that erupted from the ocean floor). Dawin documented 13 species of finch that evolved from a single ancestral finch that originated from South America. Each finch adapted to best access the resources on the island. 

Divergent Evolution: 

Species that were once similar to an ancestor diverge, becoming distinct to reduce competition. This involves larger-scale changes compared to adaptive radiation.

Example: 

Ontario forests are home to many rodents. (a) Deer mice prefer small seeds and insects, and usually nest in trees. (b) Flying squirrels are active only at night. (c) Porcupines climb trees and feed on twigs and thin bark of conifers. (d) Beavers prefer the twigs and bark of angiosperms. All species evolved from a single common ancestor. 

Convergent Evolution: 

When species without a common ancestor develop similar traits due to natural selection in similar environments

Example:

 (left) Cacti evolved in the deserts of South America and are native only to the Americas. (Right) Euphorbia evolved in the deserts of South Africa. Both have sharp spines and thick green stems for photosynthesis except cacti spines evolved from leaves, while euphorbia spines evolved from the outward growth of tissues.

Coevolution:

when one species evolves in response to another, often seen in symbiotic relationships. This "evolutionary arms race" can make species interdependent, so the extinction of one threatens the other.

Example: (a) The Madagascar Long-Spurred Orchid is pollinated by (b) a Hawk Moth whose tongue is 30cm long.

Longer spurs were naturally selected for because moths would spend more time and effort trying to get its tongue to the bottom of the spur to reach the nectar. Moth’s that spent more time were more likely to pick up pollen. Therefore orchids with longer spurs were more reproductively successful. Now, this orchid has 30cm spurs that can only be pollinated by the Hawk Moth. 

Differentiate homologous, analogous and vestigial structures**

Homologous Structure	Vestigial Structure	Analogous Structure
This is a structure with a common evolutionary ancestor that may serve a different function in the modern species.	Is an anatomical structure that is a reduced version of a structure that was once larger and functions in the organism's ancestors.	This is a structure that  performs the same function but is not similar in origin or structure.