AP BIOLOGY

Detailed explanation-1: -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.

Detailed explanation-2: -Recessive alleles only show their effect if the individual has two copies of the allele (also known as being homozygous?). For example, the allele for blue eyes is recessive, therefore to have blue eyes you need to have two copies of the ‘blue eye’ allele.

Detailed explanation-3: -For a recessive allele to produce a recessive phenotype, the individual must have two copies, one from each parent. An individual with one dominant and one recessive allele for a gene will have the dominant phenotype.

Detailed explanation-4: -A recessive trait is the weak, unexpressed trait of a dichotomous pair of alleles (dominant-recessive) that has no effect in the phenotype of heterozygous individuals.