BIOL 108 final exam study

Question 1

Define genetic diversity

Answer 1

diversity between and within populations (diversity within the same species)

Question 2

Define species diversity

Answer 2

having a variety of species

Question 3

Define ecosystem diversity

Answer 3

having a variety of ecosystem types

Question 4

List and explain the 4 ecosystem services

Answer 4

1. Provisioning services
   - materials we procure from nature
2. Regulating services
   - benefits outside of material items, such as purification of air, pollination, etc
3. supporting services
   - services that are important for maintaining the biosphere. includes O2 production, CO2 absorption, habitats
4. cultural services
   - non-material things that we gain from nature. can be spiritual or cultural, or simply for enjoyment (ie. a walk)

Question 5

Extirpation definition

Answer 5

A local extinction –> a species is completely gone in a certain area, but exists in other places in the world

Question 6

List the 4 major threats to biodiversity

Answer 6

1. Habitat loss
2. Invasive species
3. Over exploitation
4. Global climate change

Question 7

According to Darwin, what is the mechanism for descent with modification?

Answer 7

Natural selection

Question 8

Define natural selection

Answer 8

A process in which individuals of a species with more favourable traits are more likely to survive and reproduce
–> leads to descent with modification

Question 9

Speciation definition

Answer 9

formation of a new species from an ancestral species

Question 10

Microevolution definition

Answer 10

Evolution within a species over a short time period (ex. Galapagos finches)
–> ie. change in a population’s allele frequencies over generations

Question 11

An organisms phenotype is dependant on what 2 things?

Answer 11

environmental factors and its genotype

Question 12

Selective agents definition

Answer 12

Factors (biotic or abiotic) that affect population or individual survival

Question 13

Homology vs analogy

Answer 13

Homology: trait comes from a shared ancestor and was kept over time
Analogy: trait is not due to common ancestry and arose independently

Question 14

Monophyletic definition

Answer 14

A group consists of the ancestor and all of its descendants
= CLADE

Question 15

Paraphyletic definition

Answer 15

a group consists of the ancestor but not all of the descendants

Question 16

Polyphyletic definition

Answer 16

A group includes many taxa that are distantly related but leaves out their common ancestor

Question 17

List the taxonomic ranks in order

Answer 17

Domain
Kingdom
Phylum
Class
Order
Family
Genus
Species

Question 18

What is considered the smallest unit of evolutionary change?

Answer 18

populations

Question 19

in a diploid individual, how many alleles are in one gene?

Answer 19

2

Question 20

Directional selection definition

Answer 20

natural selection that favours individuals who differ from the mean phenotype in ONE DIRECTION
–> one extreme phenotype is favoured

Question 21

Disruptive selection definition

Answer 21

Natural selection that favours BOTH EXTREMES

Question 22

Stabilizing selection definition

Answer 22

Natural selection that favours against extremes and favours the mean phenotype

Question 23

Genetic drift definition

Answer 23

Random changes in a populations allele frequencies
–> most likely in small populations
–> rare alleles more likely to be lost

Question 24

Gene flow definition

Answer 24

movement of alleles between different populations of a single species

Question 25

Heterozygote advantage definition

Answer 25

An advantage that an organism has due to it having 2 different alleles of a gene (heterozygote) rather than one (homozygote). Heterozygous organisms have an increased fitness

Question 26

Frequency-dependent selection definition

Answer 26

An organism with a specific phenotype’s fitness is proportional to how frequent it is in a given population