NEET Biology Human Reproduction MCQs Set 17

Answer: (d) Endometrium

Explanation:
1. Endometrium wall periodically change in menstrual cycle.
2. Generally, menstrual cycle have four phases
3. (i) Menstrual phase (a) The soft tissue of endometrial lining of the uterus disintegrates causing bleeding.
4. (b) The unfertilized egg and soft tissue are discharged.
5. (c) It lasts 3-5 days.
6. (ii) Follicular Phase/Proliferative Phase (a) The primary follicles in the ovary grow and become a fully mature Graafian follicle.
7. (b) The endometrium of the uterus is regenerated due to the secretion of LH and FSH from anterior pituitary and ovarian hormone, estrogen.
8. (c) It least for about 10-14 days.
9. (iii) Ovulatory Phase (a) Rapid secretion of LH (LH surge) induces rupture of Graafian follicle, thereby leading to ovulation (release of ovum).
10. (b) It lasts for only about 48 hr.
11. (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.
12. (b) The endometrium thickens further and their glands secrete a fluid into the uterus.
13. c) If ovum is not fertilized, the corpus luteum undergoes degeneration and this causes disintegration of the endometrium leading to menstruation.
14. (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: (a) Statement A is correct, statement B is incorrect

Explanation:
1. Mature follicles are called Graafian follicles. After meiosis, the mature follicle gives rise to ovum, which represents the female gametocyte

Answer: (a) Lysosome

Explanation:
1. The head of sperm is composed of two regions, i.e, nuclear region and an acrosomal region. Acrosomal regions contains the acrosome, a large lysosome possessing hydrolytic enzymes which help in the penetration of the layers of cells surrounding the egg immediately before fertilization.

Answer: (a) Ectoderm

Explanation:
1. Ectoderm.
2. Fate of three germ layers
3. Mesoderm Dermis of skin, circulatory system, muscles, bones (except facial)
4. Endoderm Lining of \(\mathrm{Gl}\) tract, lining of lungs, kidney ducts and bladder, thymus, thyroid tonsils
5. Ectoderm Epidermis of skin, tooth enamel, lens and cornea of the eye outer ear Brain and spinal cord, facial bones skeletal muscles in the head

Answer: (b) Infundibulum

Explanation:
1. 1. Infundibulum 1. Perimetrium
2. It is the opening of Outer thin covering
3. fallopian tube found of uterus wall
4. near to ovaries
5. 2. Fimbriae 2. Myometrium
6. Finger like projection Middle thick layer or
7. for collecting ovum uterus wall
8. near to ovaries
9. 3. Ampulla 3. Endometrium
10. Infundibulum leads Inner layer of uterus that
11. to the wider contains glands and many
12. part of oviduct blood vesels
13. 4. Isthmus
14. Last part of oviduct
15. having a narrow
16. lumen which joins
17. the uterus

Answer: (a) 2nd month

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

Answer: (c) Reproduction

Explanation:
1. There are eight charcteristic activites common to all organisms, respiration, nutrition, metabolism, excretion, sensitivity, locomotion, reproduction and growth. The possession and practice of these characteristic activities of organisms is the way biologists identify and define life.

Answer: (c) Yolk sac

Explanation:
1. Amnion is an extra embryonic membrane that surrounds embryo in reptiles, birds and mammals. It provides a kind of private aquarium to the embryo and protects it from mechanical shock and desiccation

Answer: (b) Labia majora

Explanation:
1. Labia majora (female external genitalia) homologous to the scrotum of male

Answer: (b) A-GnRH, B-hypothalamus, C-anterior, D-LH, E-FSH

Explanation:
1. A-\(\mathrm{GnRH}\), B-Hypothalamus, C-Anterior, D-LH, E-FSH

Answer: (c) 9 month \(±\) 7 days

Explanation:
1. The duration of pregnancy in human being is about 9 month \(±7\) days, which is called gestation period. Infact, the gestation period is the time from conception till birth

Answer: (a) Lactiferous duct

Explanation:
1. Near the nipple mammary duct expand to form mammary ampullae (lactiferous sinuses) where some milk may be stored before going to lactiferous duct

Answer: (c) Oestrogen

Explanation:
1. Oestrogen is secreted from the ovary and regulates growth and development of female accessary reproductive organs, secondary sexual characters and behaviour, so when both ovaries are removed. Oestrogen level will decrease in blood.

Answer: (b) Yolk is unevenly distributed

Explanation:
1. In teloecithal egg, yolk is unevenly distributed and most of the amount of yolk is found at the vegetal pole, e.g., eggs of amphibians.

Answer: (c) Urethral meatus

Explanation:
1. The urethra originates from the urinary bladder and extends through the penis to its external opening called urethral meatus

Answer: (b) Allantois

Explanation:
1. Allantois si the extraembryonic membrane that develops in embryon of reptiles, birds and mammals as a growth from the hindgut. It acts as a urinary bladder for the storage of waste products and as means of providing the embryo with oxygen and food.

Answer: (d) Brain cells

Explanation:
1. Regeneration is the defined as replacement, repair or restoration of the lost or damaged structures or reconstitution of the whole body from a small fragment of it during post embryonic life of an organism. Brain cells have lowest power of regeneration due to highly specific differentiation.

Answer: (c) Mitochondria, centriole, axial filament

Explanation:
1. Middle piece of sperm contains mitochondria,centriole, axial filament

Answer: (d) Parthenogenesis

Explanation:
1. In a bee hive, drones are the fertile males developed parthenogenetically from the unfertilized eggs. They possess very large eyes, small pointed mandibles and lack wax producing gland. The function of drones is to mate with the queen and fertilize her.

Answer: (c) Endoderm

Explanation:
1. Endoderm.
2. Fate of three germ layers
3. Mesoderm Dermis of skin, circulatory system, muscles, bones (except facial)
4. Endoderm Lining of \(\mathrm{Gl}\) tract, lining of lungs, kidney ducts and bladder, thymus, thyroid tonsils
5. Ectoderm Epidermis of skin, tooth enamel, lens and cornea of the eye outer ear Brain and spinal cord, facial bones skeletal muscles in the head

Answer: (b) One months

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

Answer: (a) I-A, II-A, III-B, IV-A, V-B, VI-A, VII-A, VIII-A, IX-B

Explanation:
1. Correct option: (a).

Answer: (b) Hyaluronidase

Explanation:
1. Acrosome present in head of sperm, is derived from Golgi complex. It secretes a lytic enzyme hyaluronidase, which helps in the penetration of ovum.

Answer: (a) The ovum is fertilized externally and thereafter implanted in the uterus

Explanation:
1. In certain cases, where normal fertilization is not possible, ovum from the female and the sperm from the male are fused by in vitro technique. The zygote, later on, is implanted in the uterus, where futher development takes place. Patrick Steptoe and Robert Edwards first time developed ‘test tube baby technique’ in 1978.

Answer: (a) A-Labia minora, B-Hymen, C-Clitoris

Explanation:
1. A-Labia minora, B-Hymen, C-Clitoris