Evaluate the statements concerning the functional layers of the uterine wall:
(I) The perimetrium is the middle thick layer of smooth muscle. (II) The myometrium exhibits strong contractions during the delivery of the baby. (III) The endometrium is the inner glandular layer lining the uterine cavity. (IV) The endometrium undergoes cyclical changes during the menstrual cycle.
Explanation: Statements (II), (III), and (IV) are correct. Statement (I) is incorrect because the myometrium is the middle thick muscular layer, whereas the perimetrium is the outer thin membranous layer.
Question 62 of 100
📘 CLASS XII
Identify the correct statements concerning the female external genitalia:
(I) Mons pubis is a cushion of fatty tissue covered by skin and pubic hair. (II) The labia majora are paired folds of tissue under the labia minora. (III) The labia minora are fleshy folds of tissue extending down from the mons pubis. (IV) The clitoris is a tiny finger-like structure lying at the upper junction of the two labia minora.
Explanation: Statements (I) and (IV) are correct. Statements (II) and (III) are incorrect because the descriptions are interchanged. The labia majora extend down from the mons pubis, whereas the labia minora lie beneath the labia majora.
Question 63 of 100
📘 CLASS XII
Read the statements below regarding the hymen and its clinical indicators:
(I) The hymen is a membrane that always completely closes the vaginal opening. (II) It is often torn during the first coitus. (III) The hymen can be broken by active participation in sports such as horseback riding or cycling. (IV) The presence or absence of the hymen is not a reliable indicator of virginity or sexual experience.
Explanation: Statements (II), (III), and (IV) are correct. Statement (I) is incorrect because the hymen usually partially covers the vaginal opening rather than completely closing it.
Question 64 of 100
📘 CLASS XII
Analyze the statements regarding the architecture of the human mammary gland:
(I) The glandular tissue of each breast is divided into 15–20 mammary lobes. (II) Alveoli are clusters of cells in the lobes that secrete milk, which is stored in their lumens. (III) The tubules of each lobe join to form a wider mammary ampulla directly. (IV) Several mammary ducts join to form a wider mammary ampulla connected to the lactiferous duct.
Explanation: Statements (I), (II), and (IV) are correct. Statement (III) is incorrect because the tubules of each lobe first unite to form a mammary duct; several mammary ducts then join to form the mammary ampulla.
Question 65 of 100
📘 CLASS XII
Regarding the initiation of spermatogenesis, select the correct statements:
(I) Spermatogenesis begins at puberty due to a significant increase in hypothalamic GnRH. (II) GnRH acts on the posterior pituitary gland to stimulate gonadotropin secretion. (III) Gonadotropins stimulated by GnRH include Luteinizing Hormone (LH) and Follicle Stimulating Hormone (FSH). (IV) Spermatogenesis continues even in elderly men.
Explanation: Statements (I), (III), and (IV) are correct. Statement (II) is incorrect because GnRH acts on the anterior pituitary, stimulating secretion of LH and FSH.
Question 66 of 100
📘 CLASS XII
Evaluate the statements concerning the ploidy level of cells during spermatogenesis:
(I) Spermatogonia are diploid cells containing 46 chromosomes. (II) Primary spermatocytes undergo mitotic division to remain diploid. (III) Secondary spermatocytes are haploid cells containing 23 chromosomes. (IV) Spermatids are haploid cells containing 23 chromosomes.
Explanation: Statements (I), (III), and (IV) are correct. Statement (II) is incorrect because primary spermatocytes undergo the first meiotic (reduction) division to form haploid secondary spermatocytes.
Question 67 of 100
📘 CLASS XII
Concerning the divisions during spermatogenesis, identify the correct statements:
(I) The first meiotic division of a primary spermatocyte produces two unequal haploid cells. (II) The cells produced by the first meiotic division are secondary spermatocytes. (III) Secondary spermatocytes undergo the second meiotic division to produce four equal haploid spermatids. (IV) Spermatids are immediately released into the lumen as highly motile spermatozoa.
Explanation: Statements (II) and (III) are correct. Statement (I) is incorrect because the first meiotic division produces two equal haploid secondary spermatocytes. Statement (IV) is incorrect because spermatids must undergo spermiogenesis before becoming spermatozoa.
Question 68 of 100
📘 CLASS XII
Read the statements below regarding spermiogenesis and spermiation:
(I) The transformation of spermatids into spermatozoa is called spermiation. (II) After spermiogenesis, sperm heads become embedded in the Sertoli cells. (III) The release of sperms from the seminiferous tubules is called spermiation. (IV) Spermiation is a mitotic event that occurs in the interstitial space.
Explanation: Statements (II) and (III) are correct. Statement (I) is incorrect because the transformation of spermatids into spermatozoa is called spermiogenesis. Statement (IV) is incorrect because spermiation is the release of spermatozoa into the lumen of seminiferous tubules and is not a mitotic event.
Question 69 of 100
📘 CLASS XII
Examine the hormonal regulation of spermatogenesis from the following statements:
(I) LH acts on Leydig cells to stimulate androgen synthesis and secretion. (II) Androgens stimulate the process of spermatogenesis. (III) FSH acts on Sertoli cells and stimulates the secretion of factors helping in spermiogenesis. (IV) FSH acts directly on Leydig cells to inhibit estrogen production.
Explanation: Statements (I), (II), and (III) are correct. Statement (IV) is incorrect because FSH acts on Sertoli cells, not Leydig cells.
Question 70 of 100
📘 CLASS XII
Read the following statements regarding the structure of a mature human sperm:
(I) The sperm is covered entirely by a plasma membrane. (II) The anterior portion of the head contains an acrosome filled with enzymes for fertilization. (III) The middle piece contains centrioles that produce ATP for tail motility. (IV) The tail movement facilitates sperm motility which is essential for fertilization.
Explanation: Statements (I), (II), and (IV) are correct. Statement (III) is incorrect because the middle piece contains numerous mitochondria, which generate ATP for tail movement.
