Haplontic life cycle is absent in `:`

Options

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

Answer

To determine which of the given options does not exhibit a haplontic life cycle, we need to understand what a haplontic life cycle entails and analyze each of the listed organisms.

### Step-by-Step Solution:

1. **Understanding Haplontic Life Cycle**:
- In a haplontic life cycle, the dominant phase is the haploid gametophyte.
- The zygote is the only diploid stage and undergoes meiosis to produce haploid spores.
- These spores then grow into gametophytes, which produce gametes.

2. **Analyzing the Organisms**:
- **Spirogyra**: This is a green algae that exhibits a haplontic life cycle. It has a dominant haploid phase.
- **Volvox**: This is also a green algae and follows a haplontic life cycle, with a dominant haploid phase.
- **Chlamydomonas**: Another green algae that shows a haplontic life cycle, where the haploid phase is dominant.
- **Cycus (Cycads)**: This is a gymnosperm. Gymnosperms typically exhibit a diplontic life cycle, where the diploid sporophyte is the dominant stage.

3. **Conclusion**:
- Among the given options, Cycus is the only organism that does not have a haplontic life cycle. It follows a diplontic life cycle, where the sporophyte is the dominant phase.

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

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