A given trait has two alleles. It is inherited in a completely autosomal dominance pattern...
A given trait has two alleles. It is inherited in a completely autosomal dominance pattern in a diploid population. Which of the following is NOT true if this population is in Hardy-Weinberg equilibrium?
- A. Allele frequencies vary significantly from generation to generation.
- B. The frequency of the heterozygous genotype is equal to two times the frequency of the dominant allele times the frequency of the recessive allele.
- C. The frequency of the dominant allele plus the frequency of the recessive allele must add up to 1.
- D. The frequency of the dominant phenotype is equal to the frequency of the dominant allele squared.
Correct Answer: A. Allele frequencies vary significantly from generation to generation.
Explanation
Let's say that the frequency of the dominant allele (A) is represented by p, and the frequency of the recessive allele (a) is represented by q. Since these are the only two alleles for the trait, their frequencies must add up to one: p+q=1 The frequency of the AA genotype is p2, the frequency of the Aa genotype is 2pq, and the frequency of the aa genotype is q2. Hardy-Weinberg equilibrium assumes the absence of external forces like genetic drift and selective pressure. In other words, it is based on the assumption that allele frequency is relatively constant across generations.