AP BIOLOGY

Detailed explanation-1: -F1 generation = 3 dominant : 1 recessive. Hence, the probability of a child to be recessive is 1/4. Option A is the correct answer.

Detailed explanation-2: -The most common situation of an autosomal recessive disease occurs when the parents are each carrier or heterozygous (Dd). Children of carrier parents have a 25% chance of inheriting the disorder. This value is obtained by using the Punnet square model used in genetics.

Detailed explanation-3: -If you are born to parents who both carry the same autosomal recessive gene, you have a 25% (1 in 4) chance of inheriting the abnormal gene from both parents and developing the disease. You have a 50% (1 in 2) chance of inheriting one abnormal gene.

Detailed explanation-4: -If both parents are heterozygous for a trait, the probability of an offspring showing the recessive phenotype is 50%.

Detailed explanation-5: -Autosomal recessive inheritance: Two unaffected people who each carry one copy of the altered gene for an autosomal recessive disorder (carriers) have a 25 percent chance with each pregnancy of having a child affected by the disorder.