Question

Sickle cell anemia is a recessive disorder that is only expressed if inherited from which of the following?
Answer
Both grandparents
Both parents
Only the father
Only the mother

Answer 1

Both parents
A recessive allele must be received from both parents in order for it to be expressed.

Answer 2

The answer is Both parents.

Sickle cell anemia is a recessive disorder. These means that individuals with the condition must have two recessive alleles. Those alleles are inherited from the parents although parents may be healthy individuals (but they are heterozygous carriers and have one dominant and one recessive allele): If an individual inherit one recessive allele from a mother and one recessive allele from a father, it will be recessive homozygote and thus the condition will be expressed.