Haplontic life cycle is absent in `:`

Options

A. Spirogyra
B. Volvox
C. Cycas
D. Chlamydomomas

Answer

### Step-by-Step Solution:

1. **Understanding Haplontic Life Cycle**:
- The haplontic life cycle is characterized by the dominance of the gametophyte phase. In this cycle, the zygote (2n) undergoes meiosis to produce haploid spores (n).

2. **Formation of Gametophyte**:
- The haploid spores then undergo mitotic division to develop into a gametophyte, which is the free-living phase in this life cycle.

3. **Common Organisms with Haplontic Life Cycle**:
- This type of life cycle is commonly found in certain algae, such as Spirogyra, Volvox, and some species of Chlamydomonas.

4. **Identifying the Exception**:
- The question asks where the haplontic life cycle is absent. We need to identify a plant that does not follow this life cycle pattern.

5. **Analyzing the Options**:
- The organism Cycas is a gymnosperm, which typically exhibits a diplontic life cycle. In the diplontic life cycle, the sporophyte phase is dominant, not the gametophyte.

6. **Conclusion**:
- Since Cycas is a gymnosperm and follows the diplontic life cycle, it is the correct answer to the question. Therefore, the haplontic life cycle is absent in Cycas.

### Final Answer:
The haplontic life cycle is absent in **Cycas**.

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