Exam 1 Review

Front

What is heterozygote advantage?

Back

Heterozygote advantage refers to a situation where individuals with two different alleles for a particular gene (heterozygotes) have a higher fitness than those with two identical alleles (homozygotes). This phenomenon helps maintain genetic variation in a population.

Front

What type of selection selects against both extremes in a population?

Back

Stabilizing selection is a type of natural selection that favors intermediate variants and acts against extreme phenotypes, thereby maintaining the status quo of a population.

Front

What is allopatric speciation?

Back

Allopatric speciation occurs when a population is divided by a geographical barrier, leading to the evolution of distinct species due to the lack of gene flow between the separated groups.

Front

What happens to populations when gene flow increases?

Back

When gene flow between two populations increases, they become genetically similar, as alleles are exchanged between the populations, reducing genetic divergence.

Front

What are the possible causes for a rare allele to increase in frequency?

Back

Natural selection, a population bottleneck, and the founder effect can all lead to an increase in the frequency of a rare allele within a population.

Front

Define stabilizing selection.

Back

Stabilizing selection is a form of natural selection that favors average phenotypes and reduces variation by selecting against extreme traits.

Front

What is the founder effect?

Back

The founder effect occurs when a small group of individuals establishes a new population, leading to reduced genetic diversity and potentially different allele frequencies compared to the original population.

Front

Explain the concept of gene flow.

Back

Gene flow is the transfer of genetic material between populations through migration, which can introduce new alleles and increase genetic diversity.

Front

What is disruptive selection?

Back

Disruptive selection is a type of natural selection that favors individuals at both extremes of a phenotypic range, potentially leading to speciation.

Front

What is the significance of a population bottleneck?

Back

A population bottleneck is an event that drastically reduces the size of a population, leading to a loss of genetic diversity and potentially increasing the frequency of certain alleles.