Which of the following structures in Pinus are haploid

Options

A. Megaspore,endosperm and embryo
B. Microspore,megaspore and endosperm
C. Megaspore, integument and root
D. Microspore,leaf and endosperm

Answer

To determine which structures in Pinus are haploid, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Life Cycle of Pinus**:
- Pinus, like other gymnosperms, has a life cycle that includes both haploid (n) and diploid (2n) stages. The haploid stage produces gametes, while the diploid stage is the sporophyte.

2. **Identify the Structures**:
- The key structures to consider in Pinus are the megaspore, microspore, and endosperm.

3. **Megaspore**:
- The megaspore is produced from the megasporangium and is the mother cell for female gametes. It undergoes meiosis to form a linear tetrad of haploid megaspores.

4. **Microspore**:
- The microspore is produced from the microsporangium and develops into pollen grains, which are also haploid.

5. **Endosperm**:
- In Pinus, the endosperm is formed before fertilization and is haploid as well.

6. **Conclusion**:
- Therefore, the structures that are haploid in Pinus are the megaspore, microspore, and endosperm.

### Final Answer:
The haploid structures in Pinus are the megaspore, microspore, and endosperm.