Some fertility clinics now promise that a couple can choose the sex of their baby. What technique might allow for this?
a) Separating the father's sperm according to weight, as the X chromosome weighs more than the Y chromosome.
b) Separating the father's sperm according to weight, as the Y chromosome weighs more than the X chromosome.
c) Semen with more Y sperm tends to be more acidic and can be tested for.
d) Add a fluorescent dye to the father's sperm—sperm that show more fluorescence contain an X chromosome.
e) Both a) and d) are correct.
Answer: both a and b are correct