Biology [2 Mark Question Answer]

Inguinal Hernia: Sometimes due to pressure in the abdomen, the intestine bulges into the scrotum through the inguinal canal and causes the most common type of hernia.

The mammalian embryo is nourished by the nutrients which diffuse through the placenta of the mother to pass through the umbilical cord to the embryo.

The separate circulatory system facilitates quick diffusion of nutrients, metabolic waste and respiratory gases between the foetus and the mother. Bacteria and other pathogens cannot pass from the mother to the foetus because they are filtered out by the placenta. Blood pressure changes in the maternal circulation also cannot affect the foetus which has delicate blood vessels.

The human fetus is protected by the amnion layer having amniotic fluid and the yolk sac.

This enzyme dissolved the membranous covering of the ovum to facilitate the entry of sperm into the ovum.

Only one ovum is released at a time in the human female during ovulation. Although millions of sperms are ejaculated only one sperm is enough to fertilize the single ovum. This arrangement is to control and maintain the growth rate of the human population. The ovum secretes a protective wall that prevents the entry of other sperms.

Since the urethra carries both urine and semen.

One ovum under the influence of hormones is released alternatively every month.

Fetus: The fertilized zygote gets implanted in the endometrial lining of the uterus and is called the fetus after undergoing cell division.

Parturition or birth: It is the expelling of the fetus from the body of the mother and it begins by the contraction of the uterine walls resulting in labour pains.

Scrotum: Each of the testes is present in a special sac, called scrotum which is located outside the abdominal cavity. In the scrotum, the testes are maintained at temperature for less than the body temperature.

Cowper’s gland: It secretes a fluid which mixes with the sperms, offers chemical protection, and supports the swimming motion of the sperms. The mucous secretion of Cowper’s glands serves as lubricants and help to contrast the acidity of the semen.

Androgens: These are the male sex hormones that have been produced by the interstitial cells of the testes. The androgens are essential for the maturation of sex organs, development of the sperm, and for promoting secondary sexual characters such as beard, mustache, the deepening of the voice, etc.

Gametogenesis: Formation of sperms in testes and ova in the ovary is called gametogenesis.

Graffian follicle: The ovum begins to develop in the ovary and as it matures, it migrates towards the surface of the ovary and becomes surrounded by a fluid-filled follicle called the Graffian follicle. Every 28 days, on average, the most highly developed Graffian follicle ruptures to release a single ovum.

Penis: The Penis is a muscular and highly vascular copulatory organ composed of erectile tissue that serves to deposit the semen of the male into the vagina of the female during copulation or mating.

Vasectomy: It is an operative procedure in males in which a small segment of the vas deferens is removed.

Tubectomy: It is the operative procedure in females in which a small segment of the oviduct is removed.

Secondary sexual characters: They develop at the time of puberty due to hormonal activity. In a female, there is the development of breasts and change in body shape and size of hips. In a male, there is a development of a beard and mustache and deepening of the voice.

Vas deferens: The vas deferences also known as the sperm duct and receives the sperms from the epididymis. The vas deferens opens into the top of the urethra after receiving the secretions from the seminal vesicles, prostate gland, and Cowper’s gland.

(i) The fetus gets its nourishment from the mother’s blood through the placenta.
(ii) Uterus.
(iii) The process by which the ova is released from the ovary.

(i)
(1) Fallopian tube
(2) Fimbriated funnel
(3) Ureter
(4) Vagina
(5) Ovary
(6) Uterus
(7) Urinary bladder
(ii)
2 - Funnel. It collects ovum by us ciliary movement.
5-Ovary. It produces ovum.
6-Uterus. It lodges and nourishes ovum.

(i)
(1) Sperm Duct
(2) Seminiferous Tubule
(3) Lobes of Testis
(4) Epididymis.

(ii) The function of Sperm Duct: It carries sperms from testis to urethra.
The function of Seminiferous tubule: Here sperms are produced.

A – Umbilical cord
B-Cervix
C-Blood of mother flows into placenta
D-Blood of fetus flows into placenta E-Amnion
F-Amniotic fluid
G-Opening of the cervix

Accessory glands:

• Seminal vesicle - Seminal fluid
• Prostate gland - Alkaline secretion
• Bulbo-urethral gland - Lubricant