Which of the following is TRUE about sex determination in humans?
a) In the absence of a Y chromosome, the fetal gonads develop into testes, not ovaries.
b) An X chromosome is smaller than a Y chromosome.
c) Without a Y chromosome, a fertilized egg usually dies.
d) The father's sperm determines the gender of a baby.
e) One would expect babies to have two Y chromosomes about half the time.
Answer: d) The father's sperm determines the gender of a baby.