The Hardy-Weinberg principle is based on a mathematical equation that can be used to calculate the frequencies of the alleles of a particular gene in a population.

The Hardy-Weinberg equation is p² + 2pq + q² = 1

1. No mutations arise
2. The population is isolated
3. There is no selection
4. The population is large
5. Mating within the population is random

The Hardy-Weinberg calculations do not apply when the population is small or when there is significant selective pressure against a genotype, migration, or non-random mating.

Allele frequency refers to how often an allele appears in a population.

A gene pool is all the alleles of all the genes of all the individuals in a population at a given time.

A population is a group of organisms of the same species that occupies a particular space at a particular time and that can potentially interbreed.

The probability of offspring inheriting a dominant allele from both parents is p x p = p².

The probability of offspring inheriting a recessive allele from both parents is q x q = q².

The probability of an offspring inheriting a dominant allele from one parent and a recessive allele from the other is 2 x p x q = 2pq.

This is because the allele combination inherited could be pq or qp.

p + q = 1 represents that there are only two alleles of this gene in the population.

p² + 2pq + q² = 1 represents all possible combinations of alleles that can be inherited.

A dominant allele is one that is expressed in the phenotype even when there's only one copy.

A recessive allele is one that is expressed in the phenotype only when there are two copies of it.

In the Hardy-Weinberg equation, the frequency of the dominant allele in the population is shown as 'p', and the frequency of the recessive allele is shown as 'q'.