1.The testes are situated outside the abdominal cavity within a pouch called ______.

Ans: scrotum

2.What is the function of scrotum?

Ans: Scrotum is a part of male reproductive system that holds the testes.The scrotum helps in maintaining the low temperature of the testes (2–2.5o C lower than the normal internal body temperature) necessary for producing sperms.

3.Write the main functions of testis.

Ans: The main function of testes is to produce sperms and the hormone testosterone.The testes are situated inside a pouch called scrotum.

4.Where are the Leydig cells present? What is their role in reproduction?

Ans:
Leydig cells are small groups of polygonal cells that are present inside seminiferous tubules also called as interstitial spaces.
Leydig cells are also called interstitial cells.
The main function of Leydig cells is to synthesise and secrete testicular hormones called androgens that are required in sperm formation.

5.Write the main function of Sertoli cells.

Ans: Sertoli cells are present inside seminiferous tubules in which sperms are produced. The main function of Sertoli cells is to provide nutrition to the sperm cells.

6.Describe the structure of a seminiferous tubule.

Ans: The testis has 250 compartments called testicular lobules.Each lobule contains one to three highly coiled seminiferous tubules in which sperms are produced.Each seminiferous tubule is lined on its inside by two types of cells called male germ cells (spermatogonia) and Sertoli cells.The male germ cells undergo meiotic divisions finally leading to sperm formation, while Sertoli cells provide nutrition to the germ cells. The regions outside the seminiferous tubules is called as interstitial spaces, contain small blood vessels and interstitial cells or Leydig cells. Leydig cells synthesise and secrete testicular hormones called androgens.

7.What are the major functions of male accessory ducts and glands?

Ans:
The male sex accessory ducts include rete testis, vasa efferentia, epididymis and vas deferens. The main function of accessory duct is to store and transport the sperms from the testis to the outside through urethra.

The male accessory glands include paired seminal vesicles, a prostate and paired bulbourethral glands.Secretions of these glands constitute the seminal plasma which is rich in fructose, calcium and certain enzymes. The secretions of bulbourethral glands also helps in the lubrication of the penis.

8.Write short note on Male reproductive system Penis.

Ans:
The penis is the male external genitalia. It is made up of special tissue that helps in erection of the penis to facilitate insemination. The enlarged end of the penis called the glans penis is covered by a loose fold of skin called foreskin.

9.Write a short note on the human ovary?

Ans:
Ovaries are the primary female sex organs that produce the female gamete (ovum) and several steroid hormones (ovarian hormones).
The ovaries are located one on each side of the lower abdomen.
Each ovary is about 2 to 4 cm in length and is connected to the pelvic wall and uterus by ligaments.
Each ovary is covered by a thin epithelium which encloses the ovarian stroma.
The stroma is divided into two zones – a peripheral cortex and an inner medulla.

10.What is the function of infundibulum.

Ans:
The infundibulum is part of the oviducts (fallopian tubes). The shape of the infundibulum is funnel shaped and it is positioned close to the ovary.The edges of the infundibulum possess finger-like projections called fimbriae, which help in collection of the ovum after ovulation.

11.What is the function of endometrium in the female reproductive system?

Ans:
The endometrium is one of the layers that lines the uterine cavity.The endometrium undergoes cyclical changes during menstrual cycle.The endometrium is necessary for implantation of the fertilised ovum and other events of pregnancy.

12.What is the use of the myometrium layer present in the uterus?

Ans:
The myometrium exhibits strong contraction during delivery of the baby.

13.What is gametogenesis?

Ans:
The primary sex organs – the testis in the males and the ovaries in the females – produce gametes, i.e, sperms and ovum, respectively, by the process called gametogenesis.

14.What is Spermatogenesis? Briefly describe the process of Spermatogenesis.

Ans:
The process of formation of sperms from male germ cells that happens at puberty is called spermatogenesis.

The spermatogonia present on the inside wall of seminiferous tubules multiply by mitotic division and increase in numbers. Each spermatogonium is diploid and contains 46 chromosomes. Some of the spermatogonia called primary spermatocytes periodically undergo meiosis. A primary spermatocyte completes the first meiotic division (reduction division) leading to formation of two equal, haploid cells called secondary spermatocytes, which have only 23 chromosomes each. The secondary spermatocytes undergo the second meiotic division to produce four equal, haploid spermatids.

The spermatids are transformed into spermatozoa (sperms) by the process called spermiogenesis. After spermiogenesis, sperm heads become embedded in the Sertoli cells, and are finally released from the seminiferous tubules by the process called spermiation.