Exam 21: Microevolution: Genetic Changes Within Populations

How does gene flow introduce novel genetic variants into populations?

Most copies of rare recessive alleles exist in ____.

Natural selection is a quick and effective way of eliminating harmful alleles from the population.

In humans, a diploid organism, an individual's genotype includes ____ of each autosomal gene.

Characters that exist in two or more discrete states are described as exhibiting ____.

In many species, sexual selection is the most probable cause of ____, differences in the size or appearance of males and females.

Genetic drift is most likely to lead to ____.

Distinguish between quantitative and qualitative variation.

The only survivors of a colony on Venus are a man and a woman, who both happen to originally be from southern Ukraine. Their descendants will show the effect of ____.

The source of new alleles within a population is ____.

Sometimes the most abundant color form of an animal is preyed upon more extensively than less common forms. This illustrates the phenomenon of ____ selection.

Individuals with one sickle cell allele and one normal hemoglobin allele are not affected by the malaria parasite because of ____.

In an isolated population of fruit flies, 4% of the individuals have pink eyes, a homozygous recessive condition, and 96% have the dominant black eye phenotype. What percentage of the population are heterozygotes?

The maintenance of the HbS (sickle) allele in humans is an example of homozygote advantage.

Genetic variations that confer no apparent selective advantage or disadvantage in a particular environment are said to be selectively ____.

How can a researcher determine whether variation in a phenotypic trait is caused by environmental factors or by genetic differences?

The accumulation of traits that increase the relative fitness of organisms in their environment over time results in ____.

Disadvantageous recessive alleles are protected from natural selection due to ____.

Which circumstance violates the conditions of the Hardy-Weinberg model?

According to the Hardy-Weinberg principle, microevolution occurs when ____.