Deck 17: Population and Evolutionary Genetics

Question 1

Which position of a codon evolves at the highest rate?
a.All positions of a codon evolve at the same rate.
b.first position
c.second position
d.third position
e.The first and third positions evolve at the same rate.

Answer 1

third position

Question 2

Intense inbreeding is harmful because __________.

A)the proportion of homozygotes increases
B)the proportion of deleterious and/or lethal recessive alleles increases
C)inbreeding depression will be observed
D)all of the above

Answer 2

A

Question 3

Which type of evolution gives rise to new species?

A)anagenesis
B)cladogenesis
C)Both anagenesis and cladogenesis can lead to new species.
D)genetic variation

Answer 3

C

Question 4

Which of the following is an assumption of the Hardy-Weinberg law?
a.The population is small.
b.The population is affected by migration,mutation,and natural selection.
c.The population randomly mates.
d.All of the above are assumptions of the law.

Question 5

You are performing a Hardy-Weinberg test for a particular set of genotypes.You calculate the following: degrees of freedom are 1,and the chi-square value is 9.3 from Table 31,the probability is < 0.005).What can you conclude about these genotypes?
a.It is very likely that these genotypes are in H-W equilibrium.
b.It is very unlikely that these genotypes are in H-W equilibrium.
c.H-W equilibrium cannot be determined from these data.

Question 6

Which of the following prezygotic reproductive isolating mechanisms best explains why salamanders that live in trees do not successfully mate with salamanders that live in soil by rivers?

A)mechanical isolation
B)gametic isolation
C)temporal isolation
D)ecological isolation
E)behavioral isolation

Question 7

You want to know the allele frequencies for alleles B and b.The frequency of allele B you calculate as 0.55.What is the allele frequency of b?
a.0.55
b.0.45
c.1.55
d.Without knowing the number of b alleles and the number of individuals,the frequency of b cannot be determined.

Question 8

A single population becomes separated by a geographic barrier,and each population acquires genetic differences.Which of the following could happen if this barrier is removed and the two populations interact and attempt to mate?
a.Reproductive isolating mechanisms may not have evolved and thus the two species could successfully mate.
b.Prezygotic isolating mechanisms may have evolved,thus preventing the two populations from mating.
c.Postzygotic isolating mechanisms may have evolved,thus preventing the two populations from producing viable or fertile offspring.
d.All of the above could happen.

Question 9

When they are at equilibrium,allelic frequencies are determined by _________.

A)reverse mutation rates
B)forward mutation rates
C)both a and b
D)neither a nor b