Chapter 13

Question 1

Homologous Structure

Answer 1

Features that often have different functions but are structurally similar due to common ancestry.

Question 2

Vestigial Structures

Answer 2

Remnants of features that served important functions in the organisms ancestors.

Question 3

Homology

Answer 3

Similarity resulting from common ancestry

Question 4

Microevolution

Answer 4

A change in a population’s gene pool over generations.

Question 5

Sexual Dimorphism

Answer 5

Marked differences between the secondary sex characteristics of males and females.

Question 6

Intrasexual Selection

Answer 6

Individuals compete directly with members of the same sex (usually males) for mates. (Intra: within the same sex)

Question 7

Intersexual Selection

Answer 7

Individuals of one sex (usually females) are choosy in selecting their mates. (Inter: between sexes).

Question 8

Heterozygous

Answer 8

Having two different alleles for a given gene.

Question 9

Homozygous

Answer 9

Having two identical alleles for a given gene.

Question 10

Diploid

Answer 10

A cell containing two homologous sets of chromosomes, one inherited from each parent (2n cell).

Question 11

Heterozygote Advantage

Answer 11

Greater reproductive success of heterozygous individuals compare to homozygotes; tends to preserve variation in gene pools.

Question 12

Balancing Selection

Answer 12

When natural selection maintains stable frequencies of two or more phenotypic forms in a population.

Question 13

Frequency-dependent Selection

Answer 13

Type of balancing selection that maintains two different phenotypic forms in a population. (Left/right mouthed fished attacking prey. The prey guards better against attack from more common phenotype so it’s kept close to 50%)