Answer:
heterozygotes
Explanation:
In 1908 the English mathematician Godfrey H. Hardy (1877 - 1947) and the German physician Wilhem Weinberg concluded that if no evolutionary factor acted on a population that met certain conditions, the frequencies of their alleles would remain unchanged across generations. This concept refers to the Hardy-Weinberg equilibrium. In a Hardy-Weinberg problem, the 2pQ symbol represents the heterozygotes in a population. I will use an example so that you understand this better.
Suppose a population in gene equilibrium, in which the frequencies of alleles A and a (non-sex) are respectively 80% and 20% (0.8 and 0.2). Knowing that each gamete carries only one allele of each gene, it can be concluded that 80% of the gametes produced by members of this population will carry allele A, and that 20% will carry allele a.
An AA homozygous individual forms when a male gamete carrying an allele A fertilizes a female gamete also carrying an allele A. The probability of this event happening is equal to the product of the frequencies with which these types of gametes occur. Thus the probability of forming an AA individual is 0.64 or 64%.
A homozygous individual aa, in turn, originates when two gametes meet it. The probability of this event occurring is equal to the product of the frequencies with which these gametes occurred. The probability of forming an individual aa is 0.04 or 4%.
A heterozygous individual Aa forms when a male gamete A fertilizes a female gamete A, or when a male gamete fertilizes a female gamete A. The probability of these events occurring is 0.32 or 32%.
If we call p the frequency of the dominant allele, and q the frequency of the recessive allele, we can write that the frequency of AA individuals is equal to p2, the frequency of aa individuals is equal to q2, and that of heterozygous individuals Aa is equal to 2pQ.
