Question 1

A population is defined as

Accepted Answer

A)  all individuals of all species located throughout the world. 
B)  all individuals of the same species located in a given geographic region. 
C)  those individuals of the same species that have an identical genetic makeup. 
D)  all individuals of the same species located throughout the world. 
E)  all individuals of all species located in a given country.

Question 2

Which of the following is most likely to experience genetic drift?

Accepted Answer

A)  A plant species that has spread to many different habitats all around the world 
B)  A population of common rodents that includes millions of individuals 
C)  A population of endangered birds that includes only five individuals 
D)  A species of insect that occurs all across North America 
E)  A population of bears that is growing by thousands of individuals each year

Question 3

Evolution can be defined as change in__________ in a population.

Accepted Answer

The answer of Evolution can be defined as change in__________...

Question 4

In general, each species of fruit fly in the Hawaiian archipelago is restricted to a single island. One hypothesis to explain this pattern is that new species formed after a small number of flies colonized each new island. This mechanism of speciation is called

Accepted Answer

A)  artificial selection. 
B)  genetic equilibrium. 
C)  sexual selection. 
D)  the founder effect. 
E)  assortative mating.

Question 5

Explain how a recessive trait can be the most frequent phenotype in a population.

Accepted Answer

The answer of Explain how a recessive trait can be...

Question 6

-In hamsters, the dominant allele B codes for a black coat and the recessive allele b codes for a tan coat. In the population shown in the figure above, what is the most frequent phenotype?

Accepted Answer

The answer of 
-In hamsters, the dominant allele B codes...

Question 7

Environmental change causes the heritable variations in individuals that natural selection acts upon.

Accepted Answer

A) True 
 B)False

Question 8

The type of selection most likely to act on a well-adapted population in a relatively constant environment is

Accepted Answer

A)  directional. 
B)  disruptive. 
C)  stabilizing. 
D)  nonrandom. 
E)  artificial.

Question 9

Within a large population, if no mutations occur, no migration occurs, all matings are random, and each individual has an equal chance of reproducing, which of the following will probably happen?

Accepted Answer

A)  A change in allele frequency will lead to rapid evolution. 
B)  Extinction will result. 
C)  Natural selection will occur at the normal rate for that species. 
D)  A bottleneck will occur. 
E)  No evolution will occur.

Question 10

The change in one population driven by a change in an associated population is called

Accepted Answer

A)  fitness. 
B)  assortative evolution. 
C)  coevolution. 
D)  genetic drift. 
E)  random mutation.

Question 11

According to the mathematical equation used in the Hardy-Weinberg principle, if the alleles for a certain trait in a population are A1 and A2, then the proportion of individuals with the genotype__________ is represented by 2 pq.

Accepted Answer

The answer of According to the mathematical equation used in...

Question 12

Which of the following is an example of assortative mating?

Accepted Answer

A)  A female sparrow chooses a mate because he attracts her by singing a different speciesʹ song. 
B)  A dominant male elephant mates with most females in a group, excluding other males from mating with the females. 
C)  A female lizard chooses to mate with the first male she encounters. 
D)  A female sheep chooses a mate because he has previously mated with many females. 
E)  A female mouse chooses a mate because he is the same color that she is.

Question 13

In central Africa, the frequency of the sickle-cell allele has remained stable over the years because the allele protects against malaria. In the United States, malaria was eradicated by eliminating the mosquito that spreads the disease. The decreasing frequency of the sickle-cell allele in African Americans since malaria was eliminated in the United States is an example of

Accepted Answer

A)  stabilizing selection. 
B)  the founder effect. 
C)  directional selection. 
D)  genetic drift. 
E)  disruptive selection.

Question 14

Populations of organisms are constantly evolving, which means that they are always

Accepted Answer

A)  at equilibrium. 
B)  getting bigger. 
C)  changing. 
D)  becoming more like humans. 
E)  improving.

Question 15

A population carries two alleles for a trait in which T is dominant and t is recessive. In the Hardy-Weinberg equation, p2 represents the

Accepted Answer

A)  proportion of homozygous dominant individuals. 
B)  decrease in heterozygous individuals. 
C)  proportion of homozygous recessive individuals. 
D)  increase in homozygous individuals. 
E)  proportion of heterozygous individuals.

Question 16

Natural selection acts on individual phenotypes to affect the evolution of__________.

Accepted Answer

The answer of Natural selection acts on individual phenotypes to...

Question 17

Explain why new mutations appear frequently in bacterial populations but infrequently in human populations.

Accepted Answer

The answer of Explain why new mutations appear frequently in...

Question 18

Which of the following mutations would increase evolutionary fitness?

Accepted Answer

A)  One that increases the frequency of successful reproduction 
B)  One that increases the life span of the organism 
C)  One that removes other alleles from the population 
D)  One that attracts more potential mates without increasing the frequency of reproduction 
E)  One that increases the birth weight of offspring while decreasing the number of offspring

Question 19

In an equilibrium population

Accepted Answer

A)  allele frequencies do not change. 
B)  natural selection occurs. 
C)  population size cannot change. 
D)  mutation rates do not change. 
E)  rates of gene flow are constant.

Question 20

Habitat loss, natural catastrophes, and/or excessive harvesting of a species often result in

Accepted Answer

A)  artificial selection. 
B)  population bottlenecks. 
C)  increased fitness of individuals. 
D)  increased gene flow. 
E)  increased mutation rates.

Exam 16: How Populations Evolve