A phenotypically normal prospective couple seeks genetic counseling because the man knows that he has a translocation of a portion of his chromosome 4 that has been exchanged with a portion of his chromosome 12. Although he is normal because his translocation is balanced, he and his wife want to know the probability that his sperm will be abnormal. What is your prognosis regarding his sperm?
A) One-fourth will be normal, 1/4 will have the translocation, and 1/2 will have duplications and deletions.
B) All will carry the same translocation as the father.
C) None will carry the translocation because abnormal sperm will die.
D) His sperm will be sterile and the couple might consider adoption.
E) One-half will be normal and the rest will have the father's translocation.

Question

Quizplus · Accepted Answer

In a balanced translocation, during meiosis, the chromosomes can segregate in a way that results in four possible types of gametes: one normal, one with the balanced translocation, and two with duplications and deletions. Thus, 1/4 will be normal, 1/4 will have the translocation, and 1/2 will have duplications and deletions.

A Phenotypically Normal Prospective Couple Seeks Genetic Counseling Because the Man