Exam 21: Evolution: How Genotypes and Phenotypes Change Over Time

Mutations are the ultimate source of genetic variation. However, they usually occur at very low frequencies. Assume a mutation resulting in a novel allele occurs in a gene in one individual in a population of 500 diploid individuals. What is the frequency of the new allele?

An example of a phenotypic trait that allows identification of the genetic variation coding for the phenotype is:

In genetics, two organisms are part of the same population if:

Why is genetic variation critical for evolution?

What does it mean to say that an allele is "fixed" in the population?

In a given population of individuals with a particular gene of interest, the allele frequencies for that gene are equal (there are only two alleles for this gene: A and a). What are the expected genotype frequencies, assuming the population is in Hardy-Weinberg equilibrium?

Which of the following is NOT an assumption of Hardy-Weinberg equilibrium?

In a population of Mendel's garden peas, the frequency of the dominant A (yellow flower) allele is 80%. Let p represent the frequency of the A allele and q represent the frequency of the a allele. Assuming that the population is in Hardy-Weinberg equilibrium, what are the genotype frequencies?

The goldenrod gall fly lays its eggs on the terminal buds of goldenrod plants. Larvae chew through the buds and into the stems, where their saliva induces the plant to generate a gall, or outgrowth of tissue that then provides food and shelter for the developing larva. The larvae are prey to both parasitoid wasps and to birds; wasps selectively prey on larvae inside the smallest galls while birds selectively prey on larvae inside the largest galls. Goldenrod gall flies are therefore subject to _____ selection.

Traits favored by sexual selection are the same traits favored by natural selection.

What conditions must be met for alleles to be found in Hardy-Weinberg equilibrium? How much change is expected in a population that is in Hardy-Weinberg equilibrium?

Why do histone genes have a very slow molecular clock?

When the conditions of the Hardy-Weinberg equilibrium are met:

The blood type A can be produced by what genotypes?

If the allele frequency for the recessive single allele that causes a particular rare hair color is 0.02, how frequently would you expect the hair color to be present in humans?

Is natural selection the same thing as evolution?

Which of these five evolutionary forces is rare and usually NOT considered by population geneticists?

Northern elephant seals (Mirounga angustirostris) come up on a beach during breeding season. Males arrive first and establish a territory by posturing and fighting with other males. The posturing and fighting behaviors are probably the result of _____ selection.

A molecular clock is:

Which of the following big sagebrush plants is the MOST fit, based only on the information presented?