Hardy-Weinberg Equilibrium Practice Flashcards

VOCABULARY flashcards covering the principles, formulas, and calculations associated with Hardy-Weinberg Equilibrium based on lecture notes.

Diploid

A condition where individuals have alleles in pairs, which result in the genotypes of offspring from generation to generation.

$$f(A)$$

The notation used to indicate the frequency, or the commonness and rarity, of a particular allele (in this case, allele $A$) within a population.

$$2(f(A) \times f(a))$$

The mathematical formula used to calculate the frequency of the heterozygote genotype $Aa$ by accounting for the two ways the alleles can be inherited (male $A$/female $a$ or male $a$/female $A$).

Prout square

A diagram similar to a Punnett square that works at the population level to represent the pairing of alleles (using general terms like $p$, $q$, and $r$) to determine offspring genotypes.

$p$ and $q$

General terms used to represent the frequency of one allele ($p$) and the frequency of the other allele ($q$) in a population.

$$p + q = 1.0$$

The equation representing that the sum of all allele frequencies in a population with two alleles must equal $100\%$.

$$p^2 + q^2 + 2pq = 1.0$$

The mathematical expression for the sum of all genotype frequencies in a two-allele population, where each term represents a specific genotype frequency.

Allele frequency (counting method)

A process calculated by totaling the number of times an allele occurs in all genotypes (e.g., $2 \times$ homozygotes $+ 1 \times$ heterozygotes) and dividing by the total number of alleles in the population (e.g., $2 \times$ total population).

$$A = AA + \frac{1}{2}Aa$$

A simplified expression for calculating the frequency of allele $A$ based on genotype frequencies, where the frequency of the homozygote is added to half the frequency of the heterozygote.

Dynamic steady-state

The state of Hardy-Weinberg equilibrium where a population's plants continue to mate and germinate (dynamic) but the genotype and allele frequencies remain the same each year (steady-state).

$0.05$ threshold

The specific statistical difference used in course 2B to determine if observed genotype frequencies are 'different enough' from expected frequencies to suggest the population is not in equilibrium.

Hardy-Weinberg shortcut

A method to find allele frequencies by taking the square root of the frequency of the homozygous genotype (e.g., $\\sqrt{f(aa)}$); this is only valid if the population is assumed to be in equilibrium.