In humans, the gene for right-handedness (A) dominates over the gene for left-handedness (a). A right-handed woman marries

In humans, the gene for right-handedness (A) dominates over the gene for left-handedness (a). A right-handed woman marries a right-handed man. It is known that both fathers were left-handed. Determine the genotypes of all family members on the basis of “right-handedness / left-handedness condition”. What is the probability of the birth of left-handers in this family?

1. Genotypes and phenotypes P: both mother and father – Aa – t. it is indicated that their fathers are left-handed (aa), which means that one gamete (a) both receive from their fathers.
2. Genotypes and phenotypes of offspring: AA and Aa – right-handed children 75% and aa – left-handed 25%;
3. The probability of giving birth to left-handed children is 25%.
Answer: mother – Aa, father – Aa, probability – 25.

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