Plants of this group are diploid and well adapted to extreme conditions. They grow bearing sporophylls in compact structures called cones. The group in reference is

Options

A. monocots
B. dicots
C. pteridophytes
D. gymnosperms.

Answer

To solve the question regarding the group of plants that are diploid, well adapted to extreme conditions, and grow bearing sporophylls in compact structures called cones, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Characteristics**: The question states that the plants are diploid and adapted to extreme conditions. This indicates that we are looking for a group of plants that primarily exists in a sporophytic (diploid) stage.

2. **List Possible Groups**: The major groups of plants include:
- Pteridophytes
- Gymnosperms
- Angiosperms

Among these, Pteridophytes and Gymnosperms are known for their adaptation to various environments.

3. **Focus on Sporophylls**: The term "sporophylls" is crucial. Sporophylls are specialized leaves that bear spores. Both Pteridophytes and Gymnosperms have sporophylls, but they are organized differently.

4. **Consider the Structure of Cones**: The question specifies that these sporophylls are found in compact structures called cones. This is a distinctive feature of Gymnosperms, where cones (strobili) are common and contain the reproductive structures.

5. **Evaluate Adaptation to Extreme Conditions**: While both Pteridophytes and Gymnosperms can be adapted to extreme conditions, Gymnosperms are particularly known for thriving in harsh environments, such as cold climates.

6. **Conclusion**: Given that the plants in question are diploid, adapted to extreme conditions, and have sporophylls organized in cones, the correct group is **Gymnosperms**.

### Final Answer:
The group in reference is **Gymnosperms**.

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