Which of the following is not the function of tapetum?

Options

A. Secretion of enzyme and hormone
B. Formation of ubisch's body
C. Release of pollen
D. Secretion of pollen kit substance.

Answer

To determine which of the following is not a function of the tapetum, we need to understand what the tapetum is and its roles in the development of pollen grains.

### Step-by-Step Solution:

1. **Understanding Tapetum**:
- The tapetum is the innermost layer of the microsporangium (pollen sac) in flowering plants. It plays a crucial role in the development of pollen grains.

2. **Functions of Tapetum**:
- **Nourishment of Pollen Grains**: The tapetum provides essential nutrients to the developing pollen grains, which are the male gametes.
- **Secretion of Enzymes and Hormones**: The tapetum secretes various enzymes and hormones that are important for the development and maturation of pollen.
- **Formation of Pollen Coat**: It is involved in the synthesis of substances that form the pollen coat, which protects the pollen grains.
- **Release of Pollen**: However, the tapetum does not directly participate in the release of pollen; this process is primarily facilitated by the anther.

3. **Evaluating the Options**:
- **Option 1**: Secretion of enzymes and hormones - This is a function of the tapetum.
- **Option 2**: Formation of herbaceous body - This is not a recognized function of the tapetum.
- **Option 3**: Release of pollen - This is not a function of the tapetum.
- **Option 4**: Secretion of pollen kit substance - This is a function of the tapetum.

4. **Conclusion**:
- The option that is not a function of the tapetum is the **release of pollen**.

### Final Answer:
The correct answer is **Option 3: Release of pollen**.