The life cycle pattern in pteridophytes and gymnosperms is `:`

Options

A. Haplo-diplontic in bodh
B. Diplo-haplontic and diplontic respectively
C. Haplontic and diplontic respectively
D. Diplontic and haplontic respectively

Answer

To answer the question regarding the life cycle pattern in pteridophytes and gymnosperms, we will analyze the life cycles of both groups step by step.

### Step-by-Step Solution:

1. **Understanding Pteridophytes:**
- Pteridophytes exhibit a life cycle characterized by **alternation of generations**.
- They have two distinct generations: the **sporophytic generation** (diploid) and the **gametophytic generation** (haploid).
- The sporophyte (diploid) produces spores through meiosis, which then develop into the gametophyte (haploid).
- The gametophyte produces gametes (sperm and eggs), which upon fertilization form a new sporophyte.
- This pattern indicates that pteridophytes have a **diplohaplontic** life cycle, where both the diploid and haploid stages are significant.

2. **Understanding Gymnosperms:**
- Gymnosperms also undergo alternation of generations but have a different emphasis in their life cycle.
- In gymnosperms, the **sporophytic generation** is dominant and is the primary phase of the life cycle.
- The sporophyte (diploid) produces spore mother cells that undergo meiosis to form haploid spores.
- These spores develop into gametophytes, which are reduced and often dependent on the sporophyte, leading to the production of gametes.
- The life cycle of gymnosperms is classified as **diplontic**, as the dominant phase is the diploid sporophyte.

3. **Conclusion:**
- Based on the analysis, we can conclude that:
- Pteridophytes exhibit a **diplohaplontic** life cycle.
- Gymnosperms exhibit a **diplontic** life cycle.
- Therefore, the correct answer to the question is that the life cycle pattern in pteridophytes and gymnosperms is **diplohaplontic and diplontic respectively**.

### Final Answer:
The life cycle pattern in pteridophytes and gymnosperms is **diplohaplontic and diplontic respectively**.

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