Which of the following is the correct Statement about spermatogenesis ?

Options

A. spermatogenesis have 46 chromosomes and always undergo meiotic cell division .
B. Primary spermatocytes divide by mitosis .
C. Secondary spermatocytes have 23 chromosomes and undergo second meiotic division
D. Spermatozoa are transformed into spermatids .

Answer

To solve the question regarding the correct statement about spermatogenesis, we will analyze the process step by step.

### Step-by-Step Solution:

1. **Definition of Spermatogenesis**:
- Spermatogenesis is the biological process through which male gametes (sperms) are produced in the male reproductive system.

2. **Starting Point - Spermatogonia**:
- The process begins with spermatogonia, which are diploid cells (2n) containing 46 chromosomes.

3. **Mitosis of Spermatogonia**:
- Spermatogonia undergo mitosis to produce primary spermatocytes. Mitosis is an equational division, meaning the chromosome number remains the same. Therefore, primary spermatocytes also have 46 chromosomes.

4. **Meiosis I - Formation of Secondary Spermatocytes**:
- Primary spermatocytes undergo the first meiotic division (meiosis I), which is a reductional division. This results in two secondary spermatocytes, each containing half the number of chromosomes (23 chromosomes).

5. **Meiosis II - Formation of Spermatids**:
- Each secondary spermatocyte then undergoes the second meiotic division (meiosis II) to produce a total of four spermatids, each still containing 23 chromosomes.

6. **Differentiation of Spermatids into Spermatozoa**:
- The spermatids undergo a process of differentiation to become spermatozoa (mature sperm cells). This transformation involves changes in structure and function.

7. **Evaluating the Statements**:
- **Statement 1**: "Spermatogenesis has 46 chromosomes and always undergoes meiotic division." - This is incorrect because spermatogenesis starts with mitosis.
- **Statement 2**: "Secondary spermatocytes have 23 chromosomes and undergo second meiotic division." - This is correct.
- **Statement 3**: "Spermatozoa are transformed into spermatids." - This is incorrect; it is the spermatids that transform into spermatozoa.

8. **Conclusion**:
- The correct statement about spermatogenesis is that secondary spermatocytes have 23 chromosomes and undergo the second meiotic division.

### Final Answer:
The correct statement about spermatogenesis is that secondary spermatocytes have 23 chromosomes and undergo the second meiotic division.