Question

A genetic disease that causes death in infancy and has an autosomal recessive inheritance pattern can persist in a population for all of the following reasons, EXCEPT:

O it can be passed on to the next generation by a heterozygous carrier.
O if both parents are carriers, they have a 50% chance of having normal children.
O only homozygotes for the abnormal allele will have the disease.
O individuals with one abnormal allele do not show symptoms of the disease.

Answer 1

The statement that 'if both parents are carriers, they have a 50% chance of having normal children' is incorrect in explaining how a genetic disease with an autosomal recessive inheritance pattern persists, as the actual probability is 25% for normal children.

Step-by-step explanation:

A genetic disease that causes death in infancy and has an autosomal recessive inheritance pattern can persist in a population for a variety of reasons. The correct statements that explain how such a disease can persist are:

• It can be passed on to the next generation by a heterozygous carrier.
• Only individuals who are homozygous for the abnormal allele will have the disease.
• Individuals with one abnormal allele do not show symptoms of the disease and are carriers.

However, the statement that "if both parents are carriers, they have a 50% chance of having normal children" is incorrect and is the option that does NOT explain how a genetic disease persists.

Actually, if both parents are carriers, there's a 25% chance of having a child with the disease, a 50% chance of having a child who is a carrier, and a 25% chance of having a child with two normal alleles.