Read the following statements regarding the inheritance of an X-linked recessive trait in humans: (A) A carrier female transmits the mutant allele to 50 % of her sons. (B) An affected male transmits the disease to all his sons. (C) For a female to be affected, her father must be affected and her mother must be at least a carrier. (D) This pattern of inheritance is known as criss-cross inheritance. How many of the abo

Step-by-step solution

Statement (A) is correct: A carrier female ( X^C X^c ) produces two types of gametes in equal proportion. Therefore, 50 % of her sons will receive the mutant allele ( X^c ) and be affected. Statement (B) is incorrect: A male transmits his Y chromosome to his sons, not his X chromosome. Therefore, an affected male cannot transmit an X-linked disease to his sons. Statement (C) is correct: A female has two X chromosomes. To be affected ( X^c X^c ), she must inherit one mutant allele from her father (who must be affect