Human Reproduction Test - 3

By the end of sixth months of pregnancy, eye-lashes are formed in the foetus.

Zinc in semen is contributed by the prostate gland. Zinc stabilises the DNA-containing chromatin in the sperm cells.

If the egg is not fertilised, estrogen and progesterone levels drop and on Day 28, the menses begin.

Eggs in humans are alecithal, i.e., they do not contain yolk.

A morula is an early stage embryo consisting of around 16 cells in a solid ball contained within the zona pellucida. At this stage, the cells start to bind firmly together with the formation of desmosomes and gap junctions, in a process called compaction.

The maximum contribution to the semen is made by seminal vesicles. The seminal vesicles produce a yellowish viscous fluid rich in fructose and other substances that makes up about 70% of human semen.

During spermatogenesis, Meiosis II leads to the formation of four spermatids from secondary spermatocytes. The spermatids are transformed into spermatozoa(sperm) by the process of spermiogenesis. These develop into mature spermatozoa, also known as sperm cells.

Stereocilia help the lining of the epididymis to absorb excess fluids from the hollow lumen of the epididymis, along with dead or defective sperm.

Tertiary follicle is formed from the secondary follicle. The distinguishing structure of the tertiary follicle is a fluid filled chamber in the center of the follicle called antrum. The late tertiary or pre-ovulatory follicle ruptures and discharges the oocyte (secondary oocyte), ending folliculogenesis.

Ciliated cells predominate throughout the Fallopian tube, but are most numerous in the Infundibulum and Ampulla. Ciliary action plays an important role in the transfer of gametes and embryos.