Population Genetics & Hardy-Weinberg Review (Lecture Notes)

Vocabulary flashcards covering key population genetics concepts and Hardy-Weinberg terminology.

Population

A group of organisms that lives in the same place at the same time and interbreeds.

Allele frequency (p)

Frequency of the dominant allele in a population (p).

Allele frequency (q)

Frequency of the recessive allele in a population (q).

p + q = 1

The sum of allele frequencies equals 1.

Hardy-Weinberg equation

p^2 + 2pq + q^2 = 1; relates allele frequencies p and q to genotype frequencies p^2, 2pq, q^2.

Homozygous dominant

Genotype with two copies of the dominant allele (p^2 frequency).

Heterozygous

Genotype with one dominant and one recessive allele (2pq frequency).

Homozygous recessive

Genotype with two recessive alleles (q^2 frequency).

p^2

Frequency of the homozygous dominant genotype under Hardy-Weinberg equilibrium.

2pq

Frequency of the heterozygous genotype under Hardy-Weinberg equilibrium.

q^2

Frequency of the homozygous recessive genotype under Hardy-Weinberg equilibrium.

Genotype frequencies

Proportions of homozygous dominant (p^2), heterozygous (2pq), and homozygous recessive (q^2) genotypes.

Dominant allele

An allele that masks the recessive allele in a heterozygote.

Recessive allele

An allele that is expressed only in homozygous recessive individuals.

Heterozygote advantage

Situation where heterozygotes have higher fitness than either homozygote (e.g., malaria resistance in sickle-cell trait).

Sickle-cell trait (Ss)

Heterozygous for the sickle-cell allele; partial resistance to malaria with usually mild or no disease.

Malaria resistance

In malaria-endemic areas, certain genotypes (e.g., Ss) have higher survival due to reduced parasite success.

Gene frequency

Frequency of a specific allele in a population (e.g., F or f in a gene pair).