Which of the following statements are true for spermatogenesis but do ...
Statement (a): It results in the formation of haploid gametes
This statement is true for both spermatogenesis and oogenesis. In both processes, diploid germ cells undergo meiosis to produce haploid gametes. Spermatogenesis results in the formation of sperm cells, whereas oogenesis results in the formation of egg cells.
Statement (b): Differentiation of gamete occurs after the completion of meiosis
This statement is true for spermatogenesis but not for oogenesis. In spermatogenesis, the differentiation of sperm cells occurs after the completion of meiosis. The haploid spermatids undergo a series of morphological changes to form mature sperm cells. On the other hand, in oogenesis, the differentiation of the egg cell occurs during meiosis. Meiosis in oogenesis is arrested at prophase I until puberty, and only one functional egg cell is produced from each meiotic division.
Statement (c): Meiosis occurs continuously in a mitotically dividing stem cell population
This statement is true for spermatogenesis but not for oogenesis. In spermatogenesis, meiosis occurs continuously in a mitotically dividing stem cell population called spermatogonia. Spermatogonia continuously divide by mitosis to produce more stem cells and primary spermatocytes, which then undergo meiosis to produce spermatids. In contrast, oogenesis does not involve continuous meiosis. Oogonia, the stem cells in the ovaries, undergo mitotic divisions during fetal development and form primary oocytes. However, these primary oocytes are arrested at prophase I and do not complete meiosis until puberty.
Statement (d): It is controlled by the Luteinising hormone (LH) and Follicle Stimulating Hormone (FSH) secreted by the anterior pituitary
This statement is true for both spermatogenesis and oogenesis. LH and FSH, secreted by the anterior pituitary gland, play a crucial role in regulating both processes. In males, LH stimulates Leydig cells in the testes to produce testosterone, which is necessary for spermatogenesis. FSH stimulates the Sertoli cells, which support the development of sperm cells. In females, LH and FSH regulate the ovarian cycle and stimulate the growth and maturation of follicles, leading to ovulation and oogenesis.
Statement (e): It is initiated at puberty
This statement is true for both spermatogenesis and oogenesis. Both processes are initiated at puberty. In males, the onset of spermatogenesis occurs with the release of gonadotropin-releasing hormone (GnRH) from the hypothalamus, which stimulates the secretion of LH and FSH from the anterior pituitary gland. In females, the onset of oogenesis occurs with the maturation of primary oocytes and the release of LH and FSH, leading to the menstrual cycle and the potential for egg cell release.
Conclusion:
From the given statements, the most appropriate answer is option (c) - (b), (c), and (e) only. Spermatogenesis and oogenesis have similarities in terms of the formation of haploid gametes, control by LH and FSH, and initiation at puberty. However, they differ in the timing of gamete differentiation and the continuous nature of meiosis
Which of the following statements are true for spermatogenesis but do ...
(b) Differentiation of the gamete occurs after the completion of meiosis in spermatogenesis, while in oogenesis, the differentiation occurs during meiosis.
(c) Meiosis occurs continuously in a mitotically dividing stem cell population in spermatogenesis, while in oogenesis, meiosis starts during fetal development and gets arrested until puberty.
(e) Spermatogenesis is initiated at puberty, while oogenesis begins during fetal development.
Both spermatogenesis and oogenesis result in the formation of haploid gametes (a), and both processes are controlled by LH and FSH secreted by the anterior pituitary (d).