(a) | It results in the formation of haploid gametes. |
(b) | Differentiation of gamete occurs after the completion of meiosis. |
(c) | Meiosis occurs continuously in a mitotically dividing stem cell population. |
(d) | It is controlled by the Luteinising hormone (LH) and Follicle Stimulating Hormone (FSH) secreted by the anterior pituitary. |
(e) | It is initiated at puberty. |
1. (b), (c), and (e) only | 2. (c) and (e) only |
3. (b) and (c) only | 4. (b), (d) and (e) only |
List I | List II |
A. Acrosome | I. Gonadotropin |
B. Corpus luteum | II. Hyaluronidase |
C. Leydig cells | III. Estrogen |
D. Hypothalamus | IV. Testosterone |
Assertion (A): | Pregnancy is characterised by metabolic changes in the mother. |
Reason (R): | During pregnancy the level of thyroxine is increased in the maternal blood. |
1. | Both (A) and (R) are correct and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are correct but (R) is not the correct explanation of (A). |
3. | (A) is correct but (R) is not correct. |
4. | (A) is not correct but (R) is correct. |
Statement I: | The release of sperms from the seminiferous tubules is called spermiation. |
Statement II: | Spermiogenesis is the process of formation of sperms from spermatogonia. |
a. | Interstitial spaces of testis contain Leydig cells and other immunologically competent cells. |
b. | Testes are situated inside the abdominal cavity within a pouch called scrotum. |
c. | The scrotum helps in maintaining the low temperature necessary for spermatogenesis. |
d. | Each lobule of testis contains 250 seminiferous tubules in which sperms are produced. |
Column-I | Column-II | ||
a. | Milk | (i) | Spermatids are transformed into spermatozoa |
b. | Primary spermatocyte | (ii) | Stored in the cavity of alveoli |
c. | Spermiogenesis | (iii) | First menstruation begins at puberty |
d. | Menarche | (iv) | Periodically undergo meiosis |
(a) | Spermatogonia produce sperm cells by spermatogenesis that begins at puberty. |
(b) | All spermatogonia periodically undergo meiosis. |
(c) | A primary spermatocyte completes first meiotic division during embryonic development. |
(d) | The secondary spermatocytes have only 23 chromosomes each. |
Assertion (A): | During pregnancy, the level of several hormones like estrogens, progestogens, cortisol, prolactin, thyroxine, etc are increased several folds in the maternal blood. |
Reason (R): | Increased production of these hormones is essential for supporting the foetal growth, metabolic changes in the mother, and maintenance of pregnancy. |
1. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
2. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
3. | (A) is true but (R) is false. |
4. | (A) is false but (R) is true. |