Seminiferous tubules are lined by

Options

A. Male germ cells + Leyding cells
B. Sertoli cells + Leyding cells
C. Interstitial cells + Leyding cells
D. Male germ cells + Sertoli cells

Answer

To answer the question "Seminiferous tubules are lined by," we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Structure**: Recognize that seminiferous tubules are located within the male testes and are crucial for the process of spermatogenesis (the production of sperm).

2. **Identify the Components**: Each testis contains numerous testicular lobules, and each lobule houses one or more seminiferous tubules.

3. **Cell Types in Seminiferous Tubules**: The seminiferous tubules are lined by two main types of cells:
- **Male Germ Cells (Spermatogonia)**: These are the precursor cells that undergo division and differentiation to form sperm.
- **Sertoli Cells**: These cells provide support, nourishment, and protection to the developing sperm cells.

4. **Evaluate the Options**: Given the options provided:
- Option A: Male germ cell + Leydig cells (Incorrect)
- Option B: Sertoli cell + Leydig cells (Incorrect)
- Option C: Interstitial cells + Leydig cells (Incorrect)
- Option D: Male germ cell + Sertoli cell (Correct)

5. **Conclusion**: The correct answer is that seminiferous tubules are lined by male germ cells and Sertoli cells.

### Final Answer:
**Seminiferous tubules are lined by male germ cells and Sertoli cells.**