The persistent nucellus is a

Options

A. thin remaining layer of nucellus
B. thick functional layer of integument
C. multilayer of pollen sac
D. thin tissue from by endosperm

Answer

To solve the question regarding the persistent nucellus, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Nucellus**:
- The nucellus is the central part of the ovule in seed plants, which contains the female gametophyte and is involved in the development of the seed.

2. **Definition of Persistent Nucellus**:
- A persistent nucellus refers to the remaining part of the nucellus that remains after fertilization and seed development.

3. **Identifying the Options**:
- The options provided are:
1. A thin remaining layer of nucellus
2. A thick functional layer of integuments
3. A multi-layer of pollen sac
4. A thin tissue formed by endosperm

4. **Analyzing Each Option**:
- **Option 1**: A thin remaining layer of nucellus - This aligns with the definition of persistent nucellus.
- **Option 2**: A thick functional layer of integuments - This does not describe the nucellus.
- **Option 3**: A multi-layer of pollen sac - This is unrelated to the nucellus.
- **Option 4**: A thin tissue formed by endosperm - Endosperm is different from the nucellus.

5. **Conclusion**:
- Based on the analysis, the correct answer is **Option 1: A thin remaining layer of nucellus**. This is also referred to as perisperm, which is a layer of nutritive tissue surrounding the embryo in some flowering plants.

### Final Answer:
The persistent nucellus is a thin remaining layer of nucellus.

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