LAB FINAL EXAM

Allele

- one of two variants of a gene.

• we are diploid, so 2 alleles per genotype in each human

• Alleles can be dominant or recessive

• Ex.) hair color, flower petal color, etc

Allele frequency

- the frequency of an allele in a given population

• Example population, n=4: Dd, dd, DD, dd

• d allele frequency= 5/8= = 0.625= 62.5%

Genotype

the particular combination of alleles for a particular gene or locus, for a trait (like hair color)

Phenotype

the observable expression of a trait

Heterozygous genotype

Having 2 different alleles of a gene example: Dd

Homozygous recessive genotype

having two recessive alleles of a gene, dd

Homozygous dominant genotype

having two dominant alleles of a gene, DD

Hardy Weinberg Equilibrium

The principle of genetic equilibrium.

• Examines gene frequencies in a model population

• It shows us what allele frequencies we would expect if NO evolution was occurring.
- Therefore it can help us detect evolution by comparison.

• It relies on several assumptions of population normality.

Hardy-Weinberg Equilibrium Assumptions

1. Large population
2. Random Mating
3. No natural selection
4. No mutation
5. No migration

Hardy Weinberg Principle

• Relies on random mating, a large population, no immigration
or emigration, no natural/sexual selection, and no mutations.

• The purpose is to look at the model population and see how
frequently genes evolve. Then we can use that information to
look deeper into non-ideal populations.

What is Hardy-Weinburg testing for?

Microevolution: a change in allele frequencies ( of 1 gene)
that occurs over time within a population.

Hardy Weinberg Calculations

Allele frequencies:
p = frequency of dominant allele
q = frequency of recessive allele
p+q=1

Genotype frequencies:
p2= frequency of homozygous dominant
q2= frequency of homozygous recessive
2pq= frequency of heterozygous
p2+2pq+q2=1

Blood type

refers to which (if any) microscopic sugars,or antigens, a person
has attached to the surface of their red blood cells

Antigens

- these microscopic sugar markers, or sugar tags, are attached to the outside of your blood cells.

- A different blood type signifies a different kind of sugar tag your genes code for

4 Varieties of ABO-Type Antigens: A, B, AB, O

• Type A: has N-Actylgalactosamine (A- antigen) to red blood cell surface protein. (codominant with B)

• Type B: has galactose (B-antigen) to red blood cell surface.

• Type O: has no sugar to red blood cell surface protein.

The antigens that appear on YOUR red blood cells tell your immune system...

which cells belong to you, and which are foreign invaders that need to be attacked.

Rh factors are a...

• a clotting antigen that may or may not be present on RBCs

• People with the Rh-factor have positive (+) blood

• People without the Rh-Factor have negative (-) blood

A combination of your ABO antigens and Rh-factor antigens determine your...

full blood type

Antibody

- a protein produced by blood cells that can bind to a
specific part of an antigen, tagging it for removal by the
immune system

Why Clotting Happens with Blood Transfusions (gone wrong)

• The body produces antibodies as a defense against foreign proteins such as viruses. They hang out in your blood plasma.

• If you receive a blood transfusion from someone who has antigens that you don’t have, the body will create antibodies against the foreign antigen, and it will cause severe clotting (agglutination).

O is

the universal donor

AB+ is

the universal recipient

Reading a blood test

How does evolution occur? 5
mechanisms:

1) Genetic Mutations
2) Migration (emi-/immi- gration)
3) Genetic Drift
4) Natural Selection
5) Sexual Selection

1) Genetic Mutations

•Ex: Sickle Cell Anemia: Can cause blood clots, but also protects against malaria so it has been maintained in the human population.

2) Migration

when populations migrate to new regions they can change the allele frequencies of the populations they leave, and the populations they enter.

3) Genetic Drift

Population drifts towards one allele becoming more common because of random events such as bottlenecks or natural events like earthquakes.

4) Natural Selection

organisms better adapted to their environment tend to survive and produce more offspring, therefore conserving favorable traits.

5) Sexual Selection

natural selection arising through preference by one sex for certain characteristics in individuals of the other sex. Non-random mating

Convergent Evolution

- Occurs when two independent taxa (organisms) evolve the same or a similar trait independently of one another.

- Species that resemble each other often independently evolved their similar traits as a result of having to adapt to similar environments or ecological niches.

- Evidence of C.E. = Analogous Structures

Divergent Evolution

- The process by which a species evolves into two or more descendant or different forms

- Evidence of D.E. = Homologous Structures

Photosynthesis

• What is it: Photosynthesis is an energy capturing process

• Who does it: Plants, some bacteria, and some other unicellular
organisms (mostly Eukaryotic cells)

- Plants capture the light energy from the sun, transform that energy into chemical energy and store it within sugar molecules. (aka they are autotrophs!)

Chloroplasts

- The organellewhere the process of photosynthesis occurs
(in plants and eukaryotic algae, etc.)

PART 1 of photosynthesis

Photo segment

• Light captured, temporarily stored in energy storage molecules

• Water splits and forms Oxygen

• OCCURS in thylakoid membranes (in plants)

PART 2 of photosynthesis

• Sugar or glucose is made

• OCCURS in stroma of the chloroplast-fluid filled sac

What is Chlorophyll?

- Chlorophyll-Green pigment found in plants

- Responsible for the absorption of light to provide energy
for photosynthesis

Electromagnetic Spectrum

Energy of Wavelengths (nm)

Diagram of Leaf Cell

Ecology

The study of how organisms interact with each other and the physical and chemical features of their environment

Ecological Community

- A naturally occurring group of native plants, animals, and other organisms that are interacting in a unique habitat.

• Different environments have different abiotic factors that influence what kinds of organisms can survive there

• What are some abiotic factors you can think of?

Different environments have
different...

- abiotic factors (access to water, sunlight, temperatures,
mineral availability + pH, slope, wind)

- This can lead to dramatic differences in species
composition (leading to different types of communities

South-facing slopes receive more...

direct sunlight from the sun in the northern hemisphere.

- North: Less Sunlight = more water
- South: More sunlight = less water

Topographic Effects: Rain shadows

Large Mountains cause a Rain shadow effect

Riparian Community

- near a (flowing) water source
- Plants here –have high water requirements

Rocky Outcrops

- Soils with poor water retention, sometimes low essential nutrients concentrations (K, N, P)

- Serpentine outcrops –high in heavy metals

- Plants Here:Drought tolerant and adapted to harsh soils

Coastal Scrub/ Chaparral

• Shaped by Mediterranean Climate of CA

• Not dry enough to be desert, not wet enough to support full sized trees of a forest

Plants Here:
• Can survive on low rainfall
• “soft chaparral” or “coastal scrub” plants can absorb moisture from fog

Grassland

• Low Water Availability

Plants Here:
• Can survive on low rainfall
• “soft chaparral” or “coastal scrub” plants can absorb
moisture from fog

Species Types

- Native: Species that evolved in the region

- Non-Native: Species that evolved in another region and were transported here (by people or other plants/animals, on purpose or by accident) relatively recently

• Invasive: Non-natives that are negatively impacting or
outcompeting native species