Sustentacular cells are found in

Options

A. brain of rabbit and are concerned with memory
B. liver of vertebrates and are secretory
C. kidney of frog and are excretory
D. testis of rabbit and are nutritive

Explanation

**Step-by-Step Solution:**

1. **Understanding Sustentacular Cells**: Sustentacular cells, also known as Sertoli cells, play a crucial role in the male reproductive system. They are found in the seminiferous tubules of the testes.

2. **Identifying the Function**: The primary function of sustentacular cells is to provide nutritional support to developing sperm cells (spermatogenesis) and to create a protective environment for them.

3. **Analyzing the Options**: The question provides multiple options regarding where sustentacular cells can be found:
- A) Brain of rabbit
- B) Liver of vertebrates
- C) Kidney of frog
- D) Testes of rabbit

4. **Evaluating Each Option**:
- **Option A**: Brain of rabbit - The brain contains neurons, not sustentacular cells. This option is incorrect.
- **Option B**: Liver of vertebrates - The liver contains hepatocytes, which are involved in metabolic functions, not sustentacular cells. This option is incorrect.
- **Option C**: Kidney of frog - The kidney contains nephrons, which are responsible for excretion, not sustentacular cells. This option is incorrect.
- **Option D**: Testes of rabbit - This is the correct option as sustentacular cells are indeed found in the testes, specifically in the seminiferous tubules.

5. **Conclusion**: Based on the analysis, sustentacular cells are found in the testes of rabbits.

**Final Answer**: Sustentacular cells are found in the testes of rabbits.

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