# AP BIOLOGY

## EVOLUTION

### HARDY WEINBERG EQUILIBRIUM

 Question [CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
What percentage of the offspring are homozygous recessive when you cross two heterozygotes for a trait?
 A 25% B 50% C 75% D 100%
Explanation:

Detailed explanation-1: -If we cross two heterozygous individuals (Aa), then the percentage of offsprings with recessive phenotype will be: Aa x Aa = AA Aa Aa aa, so recessive phenotypes would be 1/4 = 25%. Thus, the correct answer is option D.

Detailed explanation-2: -If two heterozygotes are crossed, the probability that an offspring will be homozygous recessive is 25% or 0.25. Homozygous dominant: 25% or 0.25.

Detailed explanation-3: -What is the probability of a heterozygous offspring? There is a 50% x 50% = 25% probability that both of the alleles of the offspring are dominant.

Detailed explanation-4: -The answer is 50%. Assume that the homozygous recessive trait is denoted by aa and the heterozygote is Aa.

There is 1 question to complete.