Which of the following structures are haploid in gymnosperms?

Options

A. pollen grain, megaspore, embryo
B. Pollen grain, megaspore,endosperm
C. Megaspore,leaf,root
D. Leaf, root, integument

Explanation

To determine which structures are haploid in gymnosperms, we need to analyze the options provided and understand the reproductive structures of gymnosperms.

### Step-by-Step Solution:

1. **Understanding Haploidy in Gymnosperms**:
- In gymnosperms, haploid structures are formed through the process of meiosis. This means that these structures contain only one set of chromosomes.

2. **Identifying the Structures**:
- The key structures to consider in gymnosperms include pollen grains, megaspores, and endosperm.

3. **Analyzing Each Option**:
- **Option 1: Pollen grain, megaspore embryo** - This option is incorrect because the term "megaspore embryo" is not a recognized structure in gymnosperms.
- **Option 2: Pollen grain, megaspore, endosperm** - This option is correct. Pollen grains and megaspores are haploid, and the endosperm is also haploid as it is formed from the functional megaspore.
- **Option 3: Megaspore, leaf root** - This option is incorrect. While megaspores are haploid, "leaf root" does not refer to a haploid structure.
- **Option 4: Leaf root, integument** - This option is also incorrect. Neither "leaf root" nor "integument" are haploid structures.

4. **Conclusion**:
- The only structures that are haploid in gymnosperms from the provided options are the pollen grain, megaspore, and endosperm. Therefore, the correct answer is **Option 2: Pollen grain, megaspore, endosperm**.

### Final Answer:
The structures that are haploid in gymnosperms are **pollen grain, megaspore, and endosperm**.

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