Question 1

An example of evolution that has been readily observed is

Accepted Answer

A)  a chameleon changing colors as it moves from a leaf of one color to a leaf of another color. 
B)  increased resistance of bacteria to an antibiotic that is used to kill them. 
C)  chimpanzees learning sign language. 
D)  humans teaching dogs to obey certain commands.

Question 2

Although millions of prairie chickens once occupied Illinois,in 1993 only 50 remained.Starting in 1992,scientists moved almost 300 prairie chickens from large populations in other states to Illinois to ________ Illinois prairie chicken populations.

Accepted Answer

A)  prevent the development of nonheritable mutations in 
B)  introduce genetic variation back into 
C)  induce stabilizing selection in 
D)  cause genetic drift in

Question 3

An example of gene flow would be if pollen from a population ________ plant lands on ________.

Accepted Answer

A)  A; the same plant (mating with itself) 
B)  A; another population A plant 
C)  A; a population B plant 
D)  B; two other population B plants

Question 4

Evolution occurs when there are changes in the frequencies of alleles and genotypes in a(n)________ over time.

Accepted Answer

The answer of Evolution occurs when there are changes in...

Question 5

New alleles arise by

Accepted Answer

A)  nonrandom mating. 
B)  allele frequency. 
C)  genetic drift. 
D)  mutation.

Question 6

When robins lay a clutch of more than four eggs,their chicks are often malnourished because they have so many to feed.If the robins lay fewer than four eggs,they may not have any viable offspring.As a result,robins typically lay a clutch of four eggs.This is an example of

Accepted Answer

A)  disruptive selection. 
B)  directional selection. 
C)  stabilizing selection. 
D)  convergent evolution.

Question 7

Two unrelated species evolving to look more similar due to environmental pressures is called

Accepted Answer

A)  gene flow. 
B)  genetic drift. 
C)  convergent evolution. 
D)  divergent evolution.

Question 8

A population of 8,250 mice occupies the sand dunes in a coastal area.A severe hurricane washes out several miles of sand dunes.As a result,only 50 mice remain.The population has experienced

Accepted Answer

A)  horizontal gene transfer. 
B)  gene flow. 
C)  a founder effect. 
D)  a bottleneck.

Question 9

Both mammals and octopi have evolved similar eye structures.This is an example of

Accepted Answer

A)  convergent evolution. 
B)  divergent evolution. 
C)  disruptive selection. 
D)  directional selection.

Question 10

Convergent evolution occurs when natural selection causes distantly related organisms to

Accepted Answer

A)  evolve into the same species despite the fact that they are members of separate populations. 
B)  merge into one continuous population because of reversals in continental drift. 
C)  evolve both analogous and homologous characteristics. 
D)  evolve similar structures in response to similar environmental challenges.

Question 11

For a population to evolve,there must be genetic differences between organisms in that population.These differences arise by

Accepted Answer

A)  mutation. 
B)  a change in an organism's behavior. 
C)  natural selection. 
D)  common descent.

Question 12

Explain why a mutation in an individual's skin cells does not directly contribute to evolution.

Accepted Answer

The answer of Explain why a mutation in an individual's...

Question 13

The following image is an example of

Accepted Answer

A)  gene transfer. 
B)  genetic drift. 
C)  natural selection. 
D)  mutation.

Question 14

The only mechanism of evolutionary change that is not influenced by chance events is ________.

Accepted Answer

The answer of The only mechanism of evolutionary change that...

Question 15

Which of the following is NOT a step in the evolutionary process?

Accepted Answer

A)  Mutation results in the formation of new alleles,and sexual reproduction results in new combinations of alleles. 
B)  New genes are introduced into a population when members of that population mate with members of other species and produce offspring. 
C)  Genetic variation is inherited by the next generation of a population. 
D)  Genetic drift,gene flow,and natural selection cause allele frequencies to change over time.

Question 16

Two different species may have similar features because of

Accepted Answer

A)  genetic drift. 
B)  the founder effect. 
C)  a bottleneck. 
D)  descent from a common ancestor.

Exam 12: Mechanisms of Evolution