Section 19.2 (Exam 3)

Question 1

Define evolution.

Answer 1

change in genetic makeup of populations over time

Question 2

Define population.

Answer 2

A group of individuals of a single species that live and interbreed in a particular geographic area

Question 3

How do individuals and populations differ from an evolutionary standpoint?

Answer 3

Individuals do not evolve; populations do evolve

Question 4

What are the 4 mechanisms of evolution in addition to natural selection?

Answer 4

mutation

gene flow

genetic drift

nonrandom mating

Question 5

What is the origin of genetic variation?

Answer 5

mutation

Question 6

Define mutation.

Answer 6

any change in the nucleotide sequences of DNA

Question 7

What are the three different effects mutation could have on an organism?

Answer 7

harmful

neutral

beneficial

Question 8

What forms as a result of mutation?

Answer 8

alleles

Question 9

Define alleles.

Answer 9

different forms of a gene

Question 10

Define gene pool.

Answer 10

sum of all copies of all alleles at all loci in a population

Question 11

Define allele frequency.

Answer 11

Proportion of an allele in the gene pool

Question 12

Define genotype frequency.

Answer 12

Proportion of each genotype in the population

Question 13

What is the calculation of the allele frequency and genotype frequency used for?

Answer 13

to measure evolutionary changes

Question 14

How does selection produce new phenotypes?

Answer 14

acting on genetic variation

Question 15

Define genotype.

Answer 15

genetic makeup of an individual

Question 16

Define phenotype.

Answer 16

the set of observable characteristics of an individual

Question 17

Define artificial selection.

Answer 17

Favored phenotypes are bred together by humans to produce favorable results

Question 18

What organism did Darwin breed?

Answer 18

pigeons

Question 19

What is the function of artificial or natural selection?

Answer 19

increases the frequency of the favored trait from one generation to the next

Question 20

Define adaptation.

Answer 20

favored trait that spreads through a population by natural selection

Question 21

What is gene flow?

Answer 21

results from migration of individuals and movements of gametes (e.g., pollen) between populations

Question 22

How can new individuals affect a gene pool?

Answer 22

They can add alleles to the gene pool and changes allele frequnecies

Question 23

What is genetic drift?

Answer 23

results from random changes in allele frequencies

Question 24

What is a result of genetic drift?

Answer 24

Harmful alleles may increase in frequency, and rare advantageous alleles may be lost

Question 25

How does genetic drift vary based on population size?

Answer 25

Larger populations experience less change in genetic variation, whereas smaller populations experience a greater change in genetic variation

Question 26

What are two types of genetic drift?

Answer 26

bottleneck effect and founders effect

Question 27

What is the bottleneck effect?

Answer 27

Environmental conditions result in the survival of only a few individuals

Question 28

What is the founders effect?

Answer 28

small populations can colonize a new region

Question 29

When does nonrandom mating occur?

Answer 29

When individuals choose mates with particular phenotypes

Question 30

What is one example of nonrandom mating that is common in plants?

Answer 30

self-fertilization

Question 31

What is sexual selection?

Answer 31

nonrandom mating that favors traits that increase the chances of reproduction

Question 32

What are some examples of sexual selection?

Answer 32

bright colors, long tails, and elaborate courtship displays

Question 33

What is experimental evidence of sexual selection?

Answer 33

Long-tailed widowbird males were selected by mates if they had longer tails. This inhibited their ability to fly, and made it easier for predators to catch them, but this trait still prevailed because the female long-tailed widowbirds selected the males with longer tails more often.

Question 34

What can be a result of sexual selection?

Answer 34

significant differences between males and females of a species