Question

Read the following passage and answer the questions that follow.
Spermatogenesis is an important primary sex characteristic in humans and all other vertebrates. The process is coordinated and controlled under the influence of hormones. It starts with the onset of puberty in humans and thereafter continues. The primordial cells within the embryonic testis which differentiate into spermatogonia are the precursors of the sperms. These are located at the outer walls of the seminiferous tubules where the process of spermatogenesis proceeds.
(a) State the site of action of FSH in the testes and describe its action thereafter.
OR
(a) Describe the role of LH in the process of spermatogenesis.
(b) Name the cells and their products which undergo:
(i) Mitosis and Differentiation
(ii) Meiosis I and Meiosis II
(c) Name the accessory ducts that the sperms travel through from seminiferous tubules to reach the epididymis.

Hint:

(a) FSH acts on Sertoli cells to enhance testosterone concentration in the seminiferous tubules, while LH acts on Leydig cells to produce testosterone.
(b) Mitosis leads to the formation of primary spermatocytes, while meiosis results in secondary spermatocytes and spermatids.
(c)

Answer 1

(a) - Site of action of FSH: FSH (Follicle-Stimulating Hormone) acts on the Sertoli cells in the seminiferous tubules of the testes.
- Action of FSH: It stimulates Sertoli cells to secrete androgen-binding protein (ABP). ABP maintains a high concentration of testosterone in the seminiferous tubules, which is essential for the progression of spermatogenesis.
OR
- Role of LH in spermatogenesis: LH (Luteinizing Hormone) acts on the Leydig cells located in the interstitial space of the testes. It stimulates the Leydig cells to secrete testosterone, which plays a crucial role in the initiation and maintenance of spermatogenesis.
(b) (i) - Cells: Spermatogonia
- Product: Primary Spermatocytes
(ii) - Meiosis I:
-- Cells: Primary Spermatocytes
-- Product: Secondary Spermatocytes
- Meiosis II:
-- Cells: Secondary Spermatocytes
-- Product: Spermatids
(c) The sperms travel through the following accessory ducts:
1. Rete testis
2. Vasa efferentia
3. Epididymis