Sporoderm’ refers to the :

Options

A. Exine and intine layers collectively
B. Wall of a sporangium
C. Wall of the spore mother cell
D. Callose deposition outside the PMC

Answer

**Step-by-Step Solution:**

1. **Understanding the Term 'Sporoderm':**
- The term 'sporoderm' is derived from two parts: "sporo" which refers to spores and "derm" which means skin or outer covering.

2. **Components of Sporoderm:**
- Sporoderm specifically refers to the outer layers of pollen grains. It is made up of two main components: the inner layer called "entin" and the outer layer known as "exine."

3. **Identifying the Correct Definition:**
- When we combine the entine and exine layers of a pollen grain, we refer to this combination as the sporoderm.

4. **Eliminating Incorrect Options:**
- The other options presented in the question are incorrect:
- The wall of a sporangium is not the same as sporoderm.
- The wall of a spore mother cell is also not what sporoderm refers to.
- A callous deposit outside the primary mother cell does not define sporoderm.

5. **Conclusion:**
- Therefore, the correct definition of sporoderm is the collective term for the entine and exine layers of the pollen grain.

**Final Answer:**
Sporoderm refers to the collective layers of entine and exine in a pollen grain.

---