(c) Primary spermatocyte(46) divides through meiosis to give two secondary spermatocytes (23).
Each secondary spermatocyte divides through meiosis giving rise to two spermatids (23) which on spermiogenesis mature as sperm.
(d) Egg secretes fertilizin, due to which the acrosome of the sperm secretes antifertilizin, and due to their reaction, sperm adheres to the egg.
The acrosome reaction is the reaction which occurs in the acrosome of the sperm as it approaches the zona pellucida.
In mammals, the acrosome reaction releases hyaluronidase and acrosin; their role in fertilization is not yet clear.
It also alters a patch of pre-existing sperm plasma membrane so that it can fuse with the egg plasma membrane.
(a) After first meiotic division primary spermatocyte (diploid) gives rise to two secondary spermatocytes (haploid).
(b) In human, at the end of the first meiotic division, the male germ cells differentiate into the secondary spermatocyte.
(b) Acrosome a small pointed structure at the tip of nucleus.
It breaks down just before fertilization, releasing hydrolytic enzymes that assist penetration between follicle cells that surrounds the ovum, thus facilitating fertilization.
(a) The formation of sperms in mature human testes occurs in three important phases of gametogenesis: multiplication, growth, and maturation.
During these phases, germ cells first change into spermatogonia, then into spermatocytes during the growth phase, which subsequently develop into spermatids, not spermatoids, before finally becoming sperm.
Spermatogenesis takes approximately 74 days for the formation of mature sperm.
(c) Interstitial cells = Leydig's cells are present in testes and secrete male hormone testosterone.
(b) Vasa efferentia lead from rete testis to the epididymis.
(d) Human seminal plasma is a complex mixture of proteins, glycoproteins, peptides, glycopeptides, and prostaglandins secreted by organs of the male reproductive tract.
The components of this fluid have been implicated in the suppression of immune response, agonistic effects on sperm-egg binding, and promotion of successful implantation of the human embryo.
Seminal plasma in humans is rich in fructose, calcium and certain enzymes.
(b) The part of fallopian tube closest to the ovary is infundibulum.
Infundibulum possesses finger-like projections called fimbriae that help in collection of ovum after ovulation.
It leads to wider part of oviduct called ampulla.
The last part of oviduct is isthmus that has a narrow lumen and joins the uterus.
