NEET Biology Human Reproduction MCQs Set 06

Answer: (a) Modified sweat gland

Explanation:
1. Internally, the breast consists of the glandular tissue forming mammary glands, the fibrous tissue (connective tissue) and the fatty or adipose tissue. Mammary glands are modified sweat glands

Answer: (a) A-Cowper’s, B-Urethra, C-Alkaline, D-Mucous

Explanation:
1. A-Cowper’s gland
2. B-Urethra
3. C-Alkaline
4. D-Mucous

Answer: (c) 3rd month

Explanation:
1. 3rd month.
2. Summary of important development changes in the human embryo

Answer: (c) 10-12 cm long

Explanation:
1. The oviducts (Fallopain tubes), uterus, vagina constitute the female accessory ducts. Each Fallopian tube is about 10-12 cm long and extends from periphery of each ovary to the uterus

Answer: (a) A-heart, B-second, C-first trimester, D-second trimester

Explanation:
1. Summary of important development changes in the human embryo

Answer: (d) In the germinal epithelium of the seminiferous tubules

Explanation:
1. Sertoli’s cells or nurse cells are found in the germinal epithelium of the seminiferous tubles, which nourish the developing sperms.

Answer: (b) Ovulatory phase

Explanation:
1. The phase of menstrual cycle in women that lasts for 7-8 days, is ovulatory phase.

Answer: (b) Sertoli cells

Explanation:
1. Sertoli cells.
2. Sertoli cells present in the mammalian testis, nourishes the sperms. That’s why Sertoli cells are also called nurse cells. These cells also produces the inhibin hormone which halts spermatogenesis

Answer: (a) Red

Explanation:
1. The entire bone marrow in young ones is red and it actively synthesizes RBCs. But it gradually begin to change in yellow bone marrow at about 5 years of age.

Answer: (a) FSH

Explanation:
1. Sertoli’s cell are regulated by FSH (Follicle Stimulating Hormone) as the FSH receptors are confined to the Sertoli’s cells.

Answer: (d) Menopause

Explanation:
1. Menopause (Gr. Men-month; pausis;-N-cessation)It is a phase in woman’s life when ovulation and menstruation stops. Is occurs between 45-55 years of age. Some woman have irregular cycles for months or years prior to menopauses other simply stops menstruating abruptly. Decline in oestrogen and progesterone level leads to menopause

Answer: (b) Spermatogenesis

Explanation:
1. Spermatogenesis is the process of the formation of haploid spermatozoa (sperms) from the undifferentiated diploid primordial germs cells of the testes, which involves multiplication phase, growth phase, maturation phase and differentiation phase, whereas Spermiogenesis is the process to transformation of spermatids intospermatozoa (sperms) which involves differentiation phase.

Answer: (d) Has higher affinity for oxygen than that of an adult

Explanation:
1. Foetal haemoglobin does not sickle even in those destined to have sickle cel anaemia, i.e., haemoglobin of foetus has a higher affinity of oxygen than that of an adult.

Answer: (b) Neck

Explanation:
1. The distal centriole of the sperm divides and forms two centrioles to generate the mitotic spindle formation for cell division. The mammalian secondary oocyte (egg) does not have centriole of its own

Answer: (c) 4

Explanation:
1. Generally, menstrual cycle have four phases
2. (i)Menstrual phase (a) The soft tissue of endometrial lining of the uterus disintegrates causing bleeding.
3. (b) The unfertilized egg and soft tissue are discharged.
4. (c) It lasts 3-5 days.
5. (ii)Follicular Phase/Proliferative Phase (a) The primary follicles in the ovary grow and become a fully mature Graafian follicle.
6. (b) The endometrium of the uterus is regenerated due to the secretion of LH and FSH from anterior pituitary and ovarian hormone, estrogen.
7. (c) It least for about 10-14 days.
8. (iii)Ovulatory Phase (a) Rapid secretion of LH (LH surge) induces rupture of Graafian follicle, thereby leading to ovulation (release of ovum).
9. (b) It lasts for only about 48 hr.
10. (iv)Luteal Phase/Secretor Phase (a) In this phase the ruptured follicle changes into corpus luteum in the ovary and it begins to secrete the hormone progesterone.
11. (b) The endometrium thickens further and their glands secrete a fluid into the uterus.
12. c) If ovum is not fertilized, the corpus luteum undergoes degeneration and this causes disintegration of the endometrium leading to menstruation.
13. (d) Oestrogen and progesterone levels rise during this phase. It lasts for only 1 day. (e) During pregnancy all events of the menstrual cycle stop and there is no menstruation. The menstrual cycle permanently stops in females at the age of around 50 years. This is called menopause

Answer: (c) Golgi body

Explanation:
1. Golgi body.
2. Acrosome is the part of sperm, which is found at the head region. It is the modified Golgi body that contain many enzymes for the penetration to ovum.
3. Acrosome contains hyaluronidase proteolytic enzymes, which is popularly known as sperm lysin as it is used to penetrate egg (ovum) at the time of fertilisaton

Answer: (b) Honey bee

Explanation:
1. Parthenogenesis refers to the development of unfertilized ovum into a new individual. In honey bee, drones develop parthenogenetically.

Answer: (c) Corpus luteum

Explanation:
1. Corpus luteum acts as an endocrine gland. It is formed from the remaining structure of mature Graafian follicle which rupture at the time of ovulation and release ovum. Corona radiata and cumulus rophorus. It produces progesterone hormone during the second half of the menstrual cycle. It prepares the lining of uterus for implantation of fertilized egg.

Answer: (a) Facial

Explanation:
1. All bones are derived from the mesoderm but only facial bones which are derived from the ectoderm

Answer: (b) Blastocyst

Explanation:
1. The embryo with about 64 cells is termed as blastocyst. The process of attachment of blastocyst with the uterine wall of mother is called implantation. It occurs after 7 days of fertilization.

Answer: (b) Jelly-like connective tissue

Explanation:
1. Mucous (jelly –like) connective tissue is present mostly in embryos with Whartorn’s jelly (highly gelatinous) as the ground substance. The tissue is common in umbilical cord, cock’s comb and viterous body of eye ball.

Answer: (b) Testosterone

Explanation:
1. Leydig’s cells are endocrine in nature and present in testes of mammals. These cells in other vertebrates except mammals are known as interstitial cells. These cells secrete male sex hormone testosterone, which influence secondary sexual charscters in males. Oestrogen is female sex hormone, secreted from Graafian follicles and responsible for secondary sexual characters in female.

Answer: (b) A-200, B-300, C-60%, D-40%

Explanation:
1. A-200, B-300, C-60%, D-40%

Answer: (b) During pregnancy

Explanation:
1. \(\mathrm{hCG}\) (Human Chorionic Gonadotrophic) and HPH (Human Placental hormone) released during the pregnancy

Answer: (b) CKN

Explanation:
1. Ageing is retarded by CKN (cytokinins).