Pairing of homologous chromosomes at metaphase of meiosis I appears to be critical for proper alignment, crossing over, and subsequent separation. This pairing is facilitated by sharing of sequence homology. If X and Y chromosomes are so different, how can they achieve the necessary pairing?
A)They share short homologies at their respective tips. B)They use a unique sex-linked mechanism not present in other pairs. C)They do not need to pair because they are not a homologous pair. D)A special function of the spindle apparatus forces X and Y together.