When a harmful allele is carried on the X chromosome,
A) females are more likely to be affected.
B) males are more likely to be affected.
C) 50 percent of the female children are likely to have the disorder.
D) 50 percent of the male children are likely to be carriers of the disorder.

Question

Quizplus · Accepted Answer

Males are more likely to be affected by harmful alleles on the X chromosome because they have only one X chromosome. If that X chromosome carries a harmful allele, there is no corresponding allele on a second X chromosome to potentially counteract it, as would be the case in females who have two X chromosomes.

When a Harmful Allele Is Carried on the X Chromosome