The present models presented in Figure 3 served since the foundation for developing brand new theory models.
Spermatogenesis ( Figure 3A ): Spermatocytes bring about 4 spermatids, 2 of which may have X sex chromosome plus the other 2 spermatids have actually Y intercourse chromosome. Just 2 of this 4 spermatids take part in genetic recombination during meiosis I.
Oogenesis ( Figure 3B ): Once the 4 gametes aren’t differentiated, the assumption is that any 2 gametes can develop the oocyte that is secondary in a ovum with only 1 X chromosome.
Fertilization ( Figure 3C ): During fertilization, some of the 4 haploid spermatozoa can penetrate the ovum and fuse utilizing the X intercourse chromosome to create the zygote. The intercourse associated with offspring is determined predicated on whether or not the spermatozoon because of the X or Y chromosome unites because of the X sex chromosome into the ovum to make the zygote; leading to female (XX) or(XY that is male offspring. 4,6