Correct sequence of spermatogenesis :
(a) spermatogonia
(b) spermatids
(c) primary spermatocyte
(d) secondary spermatocyte
(e) spermatozoa

Answer

To determine the correct sequence of spermatogenesis, we need to understand the stages involved in the formation of sperm cells. Here’s the step-by-step breakdown:

### Step-by-Step Solution:

1. **Spermatogonia (a)**: The process begins with spermatogonia, which are diploid (2N) stem cells located in the seminiferous tubules of the testes. These cells undergo mitosis to produce more spermatogonia or to enter the next stage of development.

2. **Primary Spermatocyte (c)**: Some of the spermatogonia differentiate into primary spermatocytes. This is still a diploid (2N) cell. The primary spermatocyte undergoes meiosis I, which is the first meiotic division.

3. **Secondary Spermatocyte (d)**: After meiosis I, each primary spermatocyte divides to form two secondary spermatocytes. These cells are haploid (1N) because they contain half the number of chromosomes.

4. **Spermatids (b)**: Each secondary spermatocyte undergoes meiosis II, resulting in the formation of spermatids. Spermatids are also haploid (1N) and are not yet fully developed sperm cells.

5. **Spermatozoa (e)**: Finally, the spermatids undergo a transformation process called spermiogenesis, where they mature into spermatozoa (sperm cells). This is the final stage of spermatogenesis.

### Correct Sequence:
The correct sequence of spermatogenesis is:
1. Spermatogonia (a)
2. Primary Spermatocyte (c)
3. Secondary Spermatocyte (d)
4. Spermatids (b)
5. Spermatozoa (e)

### Final Answer:
The correct order is: **(a) → (c) → (d) → (b) → (e)**.

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