Chapter 23

Question 1

Evolution

Answer 1

Change in the allele frequency in a population over time.

Question 2

Gene Pool

Answer 2

All of the alleles from the organisms in a population.

Question 3

Hardy-Weinburg Equilibrium

Answer 3

When a population’s allele frequency does not change

Question 4

If all of these conditions are met, HW equilibrium will occur

Answer 4

-No mutations: No new alleles arise by mutations.
-No migration: Gene pools don’t add or remove individuals.
-Large Gene Pool: Small populations have higher chance of genetic drift.
-Random Mating: Choice not determined by phenotype.
-No Selection: Natural or Artificial selection pressures are absent.

Question 5

Gene Flow

Answer 5

Movement of alleles between populations.

Question 6

Bottleneck Effect

Answer 6

Large loss of population due to death.

Question 7

Founder Effect

Answer 7

Small Sample of gene pool break away and colonize a new population

Question 8

Stabilizing Selection

Answer 8

Occurs when the intermediate can improve the adaptation of the population

Question 9

Directional Selection

Answer 9

Occurs when an extreme phenotype is favored

Question 10

Disruptive Selection

Answer 10

Two or more extremes are favored over the intermediate Phenotype

Question 11

Sexual Selection

Answer 11

Adaptive changes in male and females that lead to an increased ability to secure a mate

Question 12

Sexual Dimorphism

Answer 12

Distinct difference in size or appearance between the sexes of an animal

Question 13

Exaptation

Answer 13

Natural selection Evolves previous trait for new use

Question 14

Heterozygous Advantage

Answer 14

eterozygote genotype has some phenotypical advantage somewhere else in the body