How many organisms show diplotic life cycle ?
Selaginella, Equisetum , Cycas , Cedrus , Ectocarpus , Fucus , sequoia

Options

A. 7
B. 5
C. 4
D. 6

Answer

To determine how many organisms from the given list show a diplontic life cycle, we need to analyze each organism based on their classification and life cycle type.

1. **Understanding Diplontic Life Cycle**:
- The diplontic life cycle is characterized by a dominant diploid (2n) sporophyte stage, which produces haploid (n) gametes through meiosis. This is typical of gymnosperms and angiosperms, as well as some algae like Fucus.

2. **Analyzing Each Organism**:
- **Selaginella**: This is a pteridophyte that exhibits a haplodiplontic life cycle, not diplontic.
- **Equisetum**: Another pteridophyte, also showing a haplodiplontic life cycle.
- **Cycas**: A gymnosperm that shows a diplontic life cycle.
- **Cedrus**: Another gymnosperm that exhibits a diplontic life cycle.
- **Ectocarpus**: This is an algae that shows a haplodiplontic life cycle.
- **Fucus**: This is an algae that exhibits a diplontic life cycle.
- **Sequoia**: A gymnosperm that also shows a diplontic life cycle.

3. **Counting the Organisms with Diplontic Life Cycle**:
- From our analysis, the organisms that show a diplontic life cycle are:
- Cycas
- Cedrus
- Fucus
- Sequoia
- Therefore, there are **4 organisms** that exhibit a diplontic life cycle.

4. **Conclusion**:
- The answer to the question is **4**.