no chance one in four two in four three in four
I gave my students this multiple choice question: Sickle cell anemia is a genetic disease caused by an autosomal recessive gene. If each parent carries one sickle cell allele, what are the chances that their child will have sickle cell anemia?

Only one answer is correct among these 4 choices:
- no chance
- one in four
- two in four
- three in four

Could you tell me which one is correct?

one in four