Name _______________________
Ch 13 & 14 homework
Ch 13
1. Compare and contrast artificial and natural selection (1 point)
Artificial selection is selective breeding for or against a trait via human intervention
Natural selection is selection for or against a trait without human intervention
Both select for or against traits, but one is human induced and the other is not.
2. What are homologous structures? Give an example of a pair of homologous
structures. (1 point)
Homologous structures are features with different functions but are structurally similar
due to common ancestry. Example is the wing of a bat and the paw of a cat
3. A population is (1 point)
A) a group of individuals of the same species living in the same place at the same
time.
B) all individuals of a species, regardless of location or time period in which they live.
C) a group of individuals of different species living in the same place at the same time.
D) a group of individuals of a species plus all of the other species with which they
interact.
E) a group of species that share a common characteristic.
4. What were Darwin’s three key observations used to form his theory of evolution (1
point)
Traits vary in a population
Traits are inherited from parent to offspring
More offspring are produced than the environment can support
5. Evolution acts on the ___individual___________________ but affects the
___population_________________.(1 point)
6. What are three ways genetic variation is produced? (1 point)
Genetic Drift
Gene Flow
Mutation
Non-random mating
Natural Selection
7. What 5 conditions must a population satisfy to remain in Hardy-Weinberg
Equlibrium? (1 point)
Very large population
Isolation of the population
Mutations don’t alter the gene pool
Random mating
Individuals are equal in reproductive success
8. Genetic drift resulting from a disaster that drastically reduces population size is called
(1 point)
A) natural selection.
B) gene flow.
C) the bottleneck effect.
D) nonrandom mating.
E) the founder effect.
9. Frequency-dependent selection, as seen in the case of the scale-eating fish in Lake
Tanganyika, tends to (1 point)
A) eliminate rare alleles and favor whichever allele is initially most frequent.
B) maintain two phenotypes in a dynamic equilibrium in a population.
C) produce random changes in allele frequencies.
D) lead to heterozygote advantage.
E) stimulate new mutations.
10. What is neutral variation? (1 point)
Natural selection on DNA that has little or no impact. Does not affect the individual or
population
Ch 14
1) A biological species is defined as a group of organisms that
A) are physically similar.
B) are genetically similar.
C) share a recent common ancestor.
D) live together in a location and carry out identical ecological roles.
E) have the potential to interbreed in nature and produce fertile offspring.
2) Which provides the most general and correct description of the idea of a reproductive
barrier?
A) any feature (of geography, behavior, or morphology) that keeps one species from
mating with another
B) a biological difference between two species that prevents them from successfully
interbreeding
C) a geographic barrier that separates two species and prevents gene flow between them
D) a difference in reproductive biology between two species that makes hybrid
individuals less fertile
E) a difference in behavior that keeps two species from interbreeding
3) Which of the following types of reproductive barriers separates a pair of species that could
interbreed except that one mates at dusk and the other at dawn?
A) temporal isolation
B) habitat isolation
C) behavioral isolation
D) mechanical isolation
E) gametic isolation
4) Which of the following types of reproductive barriers separates a pair of insect species that
could interbreed except that one mates on goldenrod flowers and the other on autumn daisies
that both blossom at the same time?
A) temporal isolation
B) habitat isolation
C) behavioral isolation
D) mechanical isolation
E) gametic isolation
5) Two species that sometimes mate and produce vigorous but sterile offspring are separated by
A) mechanical isolation.
B) gametic isolation.
C) reduced hybrid fertility.
D) reduced hybrid viability.
E) hybrid breakdown.
6) Frequently, a group of related species will each have a unique courtship ritual that must be
performed correctly for both partners to be willing to mate. Such a ritual constitutes a ________,
________ reproductive barrier.
A) mechanical . . . postzygotic
B) behavioral . . . prezygotic
C) mechanical . . . prezygotic
D) temporal . . . prezygotic
E) gametic . . . postzygotic
7) What does the term punctuated equilibrium describe?
Punctuated equilibrium is used to describe how speciation occurred. It refers to long
periods of little new speciation punctuated by periods of rapid speciation
8) The Darwin’s finches on the Galapagos islands demonstrate adaptive radiation. Using
them as an example, explain how adaptive radiation leads to speciation.
Adaptive radiation leads to speciation by the opening of niches. As new niches become
available, individuals radiate out to fill those niches. Over time they become
reproductively isolated from the parent isolation and evolve into a new species.
9) Compare and contrast allopatric and sympatric speciation.
Both involve reproductive barriers, allopatric speciation occurs when the
reproductive barrier physically divides a population (geographic separation) where
sympatric speciation occurs when a new species arises within the same geographic area
as the parent species.