In_____, a dominant and independent diploid sporophyte alternates with a short-lived, independent haploid gametophyte.

Options

A. algae
B. bryophytes
C. pteridophytes
D. gymnosperms.

Explanation

**Step-by-Step Solution:**

1. **Understanding the Life Cycle**: The question asks about a plant group where a dominant diploid sporophyte alternates with a short-lived haploid gametophyte. This indicates that we are looking for a plant group that exhibits alternation of generations.

2. **Identifying Plant Groups**: The options given are algae, bryophytes, pteridophytes, and gymnosperms. We need to analyze each group to see which fits the description.

3. **Analyzing Each Option**:
- **Algae**: Generally, algae do not have a dominant sporophyte generation; they often have a simpler life cycle without a clear alternation of generations.
- **Bryophytes**: In bryophytes, the gametophyte is the dominant stage, while the sporophyte is dependent on the gametophyte. Thus, this option does not fit the description.
- **Pteridophytes**: In pteridophytes (ferns and their relatives), the sporophyte is indeed the dominant and independent diploid stage, and it alternates with a short-lived independent haploid gametophyte. This matches the question perfectly.
- **Gymnosperms**: In gymnosperms, the sporophyte is dominant, but the life cycle does not include a short-lived independent gametophyte stage as described.

4. **Conclusion**: Based on the analysis, the correct answer is pteridophytes, as they exhibit a dominant and independent diploid sporophyte that alternates with a short-lived independent haploid gametophyte.

**Final Answer**: Pteridophytes

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