W16 L1 - Population Genetics Flashcards

Flashcards based on a lecture about population genetics, Hardy-Weinberg equilibrium, and factors affecting allele frequencies.

What is a population?

A group of individuals from the same species in a particular area.

What is a gene pool?

The genetic makeup of a population, specifically the number of alleles at every locus in all members of the population.

What can Punnett squares be used to do?

Predict genotypes among offspring of a population.

What is the Hardy-Weinberg equation for genotype frequencies?

p^2 + 2pq + q^2 = 1, where p is the frequency of the dominant allele, q is the frequency of the recessive allele, p^2 is the frequency of homozygous dominant individuals, 2pq is the frequency of heterozygous individuals, and q^2 is the frequency of homozygous recessive individuals.

What is Hardy-Weinberg equilibrium?

A population in which allele and genotype frequencies remain constant from generation to generation, indicating no evolution is occurring.

What are the five conditions for Hardy-Weinberg equilibrium?

No mutations, random mating, no natural selection, extremely large population size, and no gene flow.

What is directional selection?

Selection that favors one extreme phenotype, shifting the population's distribution towards that extreme.

What is disruptive selection?

Selection that favors both extreme phenotypes, leading to a bimodal distribution.

What is stabilizing selection?

Selection that favors intermediate phenotypes and selects against extreme phenotypes, reducing variation in the population.

What is genetic drift?

Random fluctuations in allele frequencies due to chance events, particularly significant in small populations.

What is the founder effect?

A type of genetic drift that occurs when a few individuals from a source population colonize a new area, carrying only a subset of the original population's alleles.

What is the bottleneck effect?

A type of genetic drift that occurs when a population undergoes a drastic reduction in size, resulting in a loss of genetic variation.

What are the steps to use Hardy-Weinberg to calculate allele and genotype frequencies?

Identify observed genotypes, calculate allelic frequencies, calculate expected genotypes, and compare expected vs. observed genotypes.

What is the formula to calculate allele frequencies?

p + q = 1, where p is the frequency of the dominant allele and q is the frequency of the recessive allele.