What is the difference between male meiosis and female meiosis for humans?
When a sperm and an egg fuse, the chromosomes pair and recombine. If the combination is XY, a male is created. If the combination is XX, a female is created but again, there are complications. While the 22 autosomal chromosomes (non sex chromosomes) crossing-over results in a good deal of recombination, but the Y chromosome has 95% of its information conserved that fails to recombine with the X chromosome. It is believed that the Y chromosome “hijacked” the sex-determining region or SRY locus some 300 million years ago and as a result, males produce both X and Y factors in their testes which are intiated when the SRY locus results in the expression of a protein called TDF (testis determining factor) and results in a developing embryo manufacturing seminiferous tubules, testes and a penis. Hence, all embryos start out females and only become males with the expression of genes on the SRY locus. All mammals except the platypus have the SRY locus form of sex determination. In cases where t
