Aleurone layer is

Options

A. Outer layer of scutellum in contact with endosperm
B. Layer of pericarp specialized in absorption water
C. Layer present in the ovule that guides pollen tube
D. Layer present on the outside of endosperm and having protein grains

Answer

### Step-by-Step Solution:

1. **Understanding the Aleurone Layer**: The aleurone layer is a specific layer found in seeds. It is important to identify its location and function.

2. **Location of the Aleurone Layer**: The aleurone layer is located on the outer side of the endosperm. It lies between the pericarp (the outer layer of the fruit) and the hyaline layer of the endosperm.

3. **Composition of the Aleurone Layer**: This layer is characterized by the presence of protein grains. The proteins found in this layer are essential for the seed's development.

4. **Functions of the Aleurone Layer**:
- **Embryo Protection**: The aleurone layer helps protect the developing embryo within the seed.
- **Utilization of Stored Food**: It plays a crucial role in the utilization of stored food during germination, providing nutrients to the growing embryo.

5. **Analyzing the Options**: The question provides multiple choices regarding the definition of the aleurone layer. We need to evaluate each option:
- **Option 1**: Outer layer of scutellum with contact with endosperm - Incorrect.
- **Option 2**: Layer of pericarp specialized with absorption of water - Incorrect.
- **Option 3**: Layer present in the ovule that guides the pollen tube - Incorrect.
- **Option 4**: Layer present in the outside of the endosperm having protein grains - Correct.

6. **Conclusion**: The correct definition of the aleurone layer is that it is the layer present on the outside of the endosperm, which contains protein grains.

### Final Answer:
The aleurone layer is the layer present on the outside of the endosperm having protein grains (Option 4).

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