Human Reproductive System

Glycoproteins are protein molecules with sugar chains attached that exist on cell surfaces. Research has identified specific glycoproteins on sperm surfaces that help them evade the female immune response during fertilization, allowing the sperm to survive in the reproductive tract.

Sertoli cells express FSH receptors, and FSH stimulation is essential for their function in supporting spermatogenesis. Sertoli cells produce inhibin (which feedback inhibits FSH) but do not have inhibin receptors. LH receptors are found on Leydig cells, not Sertoli cells.

New WHO (2010) criteria for normal semen analysis: volume ≥1.5ml, concentration ≥15 million/ml, total motility ≥40%, progressive motility ≥32%, normal morphology ≥4% (strict criteria). The question's option D about 'aggressive forward motility in >25%' is vague and does not match the precise WHO criterion.

Capacitation is the final maturation step sperm undergo in the female reproductive tract, which includes the acrosome reaction. The acrosome releases enzymes to penetrate the egg's zona pellucida. It does not involve sperm size change, nuclear chromatin alteration, or mitochondrial alignment.

The sperm's middle piece contains the centriole (which forms the basal body of the flagellum) and mitochondria spirally wrapped around it, providing energy for motility. The nucleus is in the head, and while proteins are components of all cell parts, centriole is the specific organelle located in the middle piece that anchors the flagellum.

Sex cells are also called as gametes. Gametes are the reproductive cells produced by sex organs, the gonads of the body.

A fertilised egg is called a zygote.

The fertilisation which takes place inside the female body is called internal fertilisation. Internal fertilisation occurs in many animals including humans, cows, dogs, hens, etc.

This is true. The cleavage in the fertilised egg of humans starts when the egg is in fallopian tube.

In mammals, fertilization (the fusion of sperm and egg) occurs in the fallopian tubes (also called oviducts), not in the ovary or uterus. The ovulated egg is swept into the fallopian tube where it may encounter sperm. After fertilization, the zygote travels to the uterus for implantation. This is why ectopic pregnancies can occur in the fallopian tubes if the fertilized egg fails to reach the uterus.

Anti-Müllerian hormone (AMH) is secreted by sertoli cells of the testes during embryogenesis of the foetal male. 

Parthenogenesis is the development of an embryo from an unfertilized egg. It occurs naturally in some species like bees, ants, and aphids. Gametogenesis is the formation of gametes, oogenesis is egg formation, and metamorphosis is the transformation process in organisms.

 The ostrich is the largest living species of bird and lays the largest eggs of any living bird.

The ovum (plural: ova) is the female germ cell or reproductive cell in mammals. Neurons are nerve cells, leukocytes are white blood cells, and erythrocytes are red blood cells - none of these are germ cells. Germ cells are specifically involved in reproduction (sperm and egg).

Human sex is determined by chromosome combinations: females have XX and males have XY. When an X-bearing sperm fertilizes an X-bearing ovum (always X), the resulting zygote is XX and develops as female. Only when a Y-bearing sperm fertilizes the ovum does the result be XY (male).