Which of the following does NOT contribute to variability of the offspring in sexual reproduction?
a) a brother and a sister producing children together
b) combining genes from two unrelated parents during fertilization
c) the different ways homologous can separate in Metaphase I
d) crossing over in Prophase I of meiosis
e) the swapping of genetic information between homologues during meiosis
Answer: a brother and a sister producing children together