NEET BIOLOGY

Detailed explanation-1: -A woman who is a carrier of an X-linked recessive disorder has a 25% chance of having an unaffected son, a 25% chance of having an affected son, a 25% chance of having an unaffected daughter and a 25% chance of having a daughter who also is a carrier.

Detailed explanation-2: -With each pregnancy, a woman who carries an altered gene for X-linked recessive has a 50 percent chance of having sons who are affected and a 50 percent chance of having daughters who carry one copy of the altered gene.

Detailed explanation-3: -Someone who has one abnormal gene (but no symptoms) is called a carrier. Carriers can pass abnormal genes to their children. The term “sex-linked recessive” most often refers to X-linked recessive.

Detailed explanation-4: -Females may get the defective gene either from her mother’s defective X, or, if her father has the disorder, from her father. In either case, the girl will be a carrier and will probably pass the defect to her offspring.

Detailed explanation-5: -Sons will be affected if they inherit the mutated X-linked gene from their mother. Fathers cannot pass X-linked recessive conditions to their sons.