Question 1

One of the assumptions of the Hardy-Weinberg theorem is that

Accepted Answer

A) mating within the population is nonrandom. 
B) the size of the population is small. 
C) gene frequencies change by chance alone. 
D) migration into and out of the population occurs regularly. 
E) mutations must not occur or a mutational equilibrium must exist.

Question 2

An excellent example of stabilizing selection is the external body form of a:

Accepted Answer

A) horseshoe crab. 
B) dendrobatid Darwin's finch. 
C) peppered moth. 
D) modern horse.

Question 3

The biological definition of a __________ is a group of populations in which genes are actually,or potentially,exchanged through inter-breeding.

Accepted Answer

A) species 
B) cohort 
C) cline 
D) subspecies 
E) community

Question 4

The study of the genetic events that occur in a gene pool is

Accepted Answer

A) geneology. 
B) molecular biology. 
C) population genetics. 
D) phenology. 
E) molecular genetics.

Question 5

A form of natural selection that occurs when both phenotypic extremes are selected against is __________ selection.

Accepted Answer

A) directional 
B) deleterious 
C) discretionary 
D) disruptive 
E) stabilizing

Question 6

Vertebrate hemoglobin and myoglobin are thought to have arisen from a common ancestral molecule due to __________ and subsequent modification.

Accepted Answer

A) gene duplication 
B) multiple replication of DNA 
C) crossing over 
D) aneuploidy 
E) multiple transcription of mRNA

Question 7

The unusual gene frequencies of the Dunker population of eastern Pennsylvania are due to this phenomenon,which is seen frequently when small groups with unrepresentative gene frequencies break off from a larger population.

Accepted Answer

A) unidirectional selection 
B) population bottleneck 
C) neutral allele 
D) disruptive selection 
E) founder effect

Question 8

Genetic drift is most likely to have noticeable effects in:

Accepted Answer

A) large populations where migration occurs regularly. 
B) small populations where migration occurs regularly. 
C) large populations where mutation occurs regularly. 
D) small, isolated populations. 
E) small populations where mutation and migration occur regularly.

Question 9

Overhunting of the elephant seal dramatically reduced its numbers in the 1800s.The population has since increased,but due to the _____________ effect its genetic diversity is still very low.

Accepted Answer

A) bottleneck 
B) neutral 
C) disruptive 
D) founder 
E) reduction

Question 10

Mutational equilibrium exists when

Accepted Answer

A) only neutral mutations are occurring. 
B) only positive mutations are occurring. 
C) only negative mutations are occurring. 
D) mutations from wild-type to mutant are balanced by mutations from mutant to wild-type. 
E) mutation pressure becomes higher than the influence of genetic drift.

Question 11

When natural selection favors certain phenotypes in a population,the population is responding to:

Accepted Answer

A) selection pressure. 
B) peer pressure. 
C) teleology. 
D) equilibrium pressure. 
E) genetic drift.

Question 12

When the Hardy-Weinberg equilibrium is achieved,evolution

Accepted Answer

A) occurs slowly and at a constant rate. 
B) occurs rapidly and at a constant rate. 
C) occurs in "bursts." 
D) does not occur. 
E) alternates between a constant rate and "bursts," but never ceases.

Exam 5: Evolution and Gene Frequencies