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Question 8 (11.111111111 points)

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A genetic counselor meets with a couple who are both carriers for a recessive genetic condition. They want to understand the probability that their children will be affected. Using Mendelian genetics principles, what can the counselor tell them about inheritance probabilities?
Question 8 options:

The inheritance pattern is too complex to predict without extensive genetic testing

Each child has a 25% chance of being affected, 50% chance of being a carrier, and 25% chance of having two normal alleles

No children will be affected, but all will be carriers like their parents

All children will definitely be affected because both parents carry the recessive allele

Answer 1

Each child has a 25% chance of being affected, 50% chance of being a carrier, and 25% chance of having two normal alleles.

Explanation: For a recessive condition when both parents are heterozygous carriers (Aa × Aa), a Punnett square gives genotypes: 25% AA (unaffected, non‑carrier), 50% Aa (unaffected carrier), 25% aa (affected). Each pregnancy is an independent event with the same probabilities.