NEET Biology Human Reproduction MCQs Set 22

Answer: (a) Mesoderm

Explanation:
1. Notochord, connective tissues including loose areolar tissue, ligaments, tendons, dermis of skin, specialized connective tissue like adipose tissue, reticular tissue, cartilage and bones are mesodermal in origin.

Answer: (a) Endocrine gland

Explanation:
1. Placenta release oestrogens, progesterone, \(\mathrm{hCG}\) and relaxin. That’s why it can be considered as endocrine gland

Answer: (c) A-Spermatogenesis; B-Sertoli cell

Explanation:
1. A-Spermatogenesis; B-Sertoli cells

Answer: (b) Testosterone

Explanation:
1. If testes are removed before maturity, the secondary sexual characteristics will not develop due to absence of male hormone testoterone. Such a condition is known as eunuchoidism.

Answer: (d) Help in the collection of the ovum after ovulation

Explanation:
1. The part of the fallopian tubes (oviducts) closer to the ovary is the funnel-shaped infundibulum. The edges of the infundibulum possess finger-like projections called fimbriate, which help in collection of the ovum after ovulation.

Answer: (a) Secondary oocyte

Explanation:
1. Ovum is a secondary oocyte which is released from mature Graafian follicle of an ovary

Answer: (d) All of the above

Explanation:
1. To control the human population, many birth control methods can be used, such as hormonal method, i.e., use of contraceptive pills (oestrogen and progesterone are main constituents), mechanical prevention method i.e., use of IUCDs (Intra Uterine Contraceptive Devices), surgical sterilization methods, like tubectomy (surgical removal of fallopian tubules) or vasectomy (surgical removal of vas deferens).

Answer: (a) Oestrogen

Explanation:
1. Oestrogen is the dominant hormone controlling the proliferative phase of the uterine endometrium layer

Answer: (b) Pattern of cleavage

Explanation:
1. The mode of cleavage is determined by the amount of yolk and its distribution.

Answer: (a) Luteinizing hormone – failure of ovulation

Explanation:
1. Ovulation occurs under the influence of LH and FSH of anterior pituitary gland.

Answer: (c) hGH

Explanation:
1. According to endocrine theory, the level of human growth hormone (hGH) declines to about half of adults with passage of time.

Answer: (a) Foetal membranes

Explanation:
1. Extra embryonic membrane are also called foetal membrane.
2. Extraembryonic or Foetal Membranes
3. The growing embryo/foetus develops four membranes called the extraembryoic or foetal membranes. These include chorion, aminion, allantois and yolk sac
4. (i)Chorion It is made up of trophoblast outside and somatopleuric extraembryonic mesoderm inside. It completely surrounds the embryo and protects it. It also takes part in the formation of placenta
5. (ii)Amnion It is composed of trophoblast inside and somatopleuric extraembryonic mesoderm outside. The space between the embryo and the amnion is called the amniotic cavity, which is filled with a clear, watery fluid secreted by both the embryo and the membrane. The amniotic fluid prevents dessication of the embryo and acts as a protective cushion that absorbs shocks
6. (iii)Allantois The allantois is composed of endoderm inside and splanchnopleuric extraembryoic mesoderm outside. It is a sac like structure, which arises from the gut of the embryo near the yolk sac. In human the allantois is small and non-functional except for furnishing blood vessels to the placenta
7. (iv)Yolk Sac The primary yolk sac consists of endoderm inside and splanchnopleuric extraembryoic mesoderm outside. The yolk sac is non-functional in human beings except that it functions as the site of early blood cell formation

Answer: (d) 6 hrs

Explanation:
1. Capacitation takes about 5-6 hours.
2. Capacitation of Sperm The sperms in the female is genital tract are made capable of fertilizing the egg by the secretion of female genital tract. These secretions of the female genital tract removes the coating substances deposited on the surface of the sperms, particularly those on acrosome. Thus, the receptor sites on the acrosome are exposed and sperm become active to penetrate the egg. This phenomenon of sperm activation in mammals is called capacitation. It takes about 5-6 hr for capacitation of sperm

Answer: (a) Fallopian tubes

Explanation:
1. Oviducts are also called Fallopian tubes. These (two) terms are used interchangeability

Answer: (a) FSH

Explanation:
1. FSH (Follicle Stimulating Hormone), secreted by anterior lobe of pituitary, stimulates sperm formation in male and growth of ovarian follicles in the females.

Answer: (b) Placenta as well as fully developed foetus

Explanation:
1. The signals for parturition originates from the fully developed foetus and the placenta, which induce mild uterine contraception called foetal ejection reflex.

Answer: (d) 28 weeks

Explanation:
1. 28 weeks.
2. Summary of important development changes in the human embryo