Question

Which of the following statements below is false?

A) Normally in humans, all the sons of a female homozygous for an X-linked recessive gene will
inherit that trait.
B) Normally in humans, a male that is carrying an X-linked dominant trait will pass it to all his
daughters.
C) At meiosis I, the X and Y chromosomes line up as if they were homologs.
D) Normally in humans, females are carriers of X-linked recessive traits if they are
heterozygous.
E) Normally in humans, all the sons of a male showing an X-linked phenotype will inherit the
trait.

Answer 1

The false statement is E) Normally in humans, all the sons of a male showing an X-linked phenotype will inherit the trait. Males transmit their Y chromosome to sons and X chromosome to daughters, so they cannot pass X-linked traits to their sons.

Step-by-step explanation:

The false statement among the ones you've listed is E) Normally in humans, all the sons of a male showing an X-linked phenotype will inherit the trait. The reason this statement is false is because males transmit their X chromosome to their daughters and their Y chromosome to their sons. Therefore, a male cannot pass an X-linked trait to his sons, but he will pass it to all of his daughters.

Understanding X-linked recessive traits and transmission patterns helps to clarify this. With X-linked recessive diseases, males either have the disease or are unaffected; they cannot be carriers. Females can be carriers if they are heterozygous for the trait, which means they inherit a recessive disease allele from one parent and a normal allele from the other. This can result in them passing on the disease to sons or carrier status to daughters.

An X-linked dominant trait follows a different pattern, such that if a male carries an X-linked dominant trait, he will pass it to all his daughters but none of his sons, as sons receive the Y chromosome from their father