BZ 110 Population Review

If gene frequencies in a population stay the same from generation to generation, is the population evolving?

• True

• False

___________ selection occurs when one phenotypic extreme is selected against. (Ex: Peppered Moth)

• Disruptive

• Directional

• Stabilizing

• Mutating

________ selection occurs when the average phenotype is at a disadvantage within an environment, two opposite or "extreme" traits favored instead. (ex: Plainfin midshipman fish)

• Directional selection

• Disruptive selection

• Stabilizing selection

• Genetic selection

How did the icefish antifreeze gene arise?

• The antifreeze gene was caused by a single mutation

• An existing gene was duplicated. It then acquired mutations, which caused it to have a different function.

• Cold Antarctic waters caused the mutation that created the antifreeze gene

• None of the above

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

• gene frequencies change by chance alone

• mutations occur regulary

• the size of the population is small

• Mating within the population is random

Genetic drift is most likely to have noticeable effects in

• small, isolated populations

• large populations where migration occurs regularly

• small populations where mutation and migration occur regularly

• large populations where mutation occurs regularly

________ occurs when chance events (natural disaster) influences the gene frequencies of a population. More likely to occur in small isolated populations.

• Gene flow

• Natural selection

• Adaptation

• Genetic drift

A type of genetic drift where a few individuals from a population start a new population with a different allele frequency than the original population.

• Bottleneck effect

• Founder effect

• Genetic drift

• Adaptive radiation

A type of genetic drift that results from a drastic reduction in population size. Usually reduces genetic variation alleles are lost from the gene pool.

• Bottleneck effect

• Genetic drift

• Founder effect

• Adaptive raditation

Both phenotypic extremes are deleterious, narrow phenotypic range as a result of environmental constancy. (ex: horseshoe crabs)

• Disruptive selection

• Directional selection

• Stabilizing selection

• Adaptation