Select an incorrect statement for plant life cycle and alteration of generations

Options

A. Haplontic life cycle is found in Volvox Fucus and Spirogyra
B. Diplontic life cycle is found in gymnosperms and angiosperms
C. Most algal genera are haplontic
D. Haploid spores divide by mitosis to form a haploid plant body

Answer

To solve the question about selecting an incorrect statement regarding plant life cycles and alteration of generations, we will analyze each statement provided.

### Step-by-Step Solution:

1. **Understand the Types of Life Cycles**:
- Plants exhibit three main types of life cycles: haplontic, diplontic, and haplodiplontic.
- Haplontic life cycle: The haploid phase is dominant, and meiosis produces haploid spores.
- Diplontic life cycle: The diploid sporophyte is dominant, and the haploid phase is represented only by gametes.
- Haplodeplontic life cycle: Both haploid and diploid phases are present, with the haploid phase being predominant.

2. **Analyze Each Statement**:
- **Statement 1**: "Haplontic life cycle is found in Volvox, Fucus, and Spirogyra."
- **Analysis**: While Volvox and Spirogyra exhibit a haplontic life cycle, Fucus actually has a diplontic life cycle. Thus, this statement is incorrect.

- **Statement 2**: "Diplontic life cycle is found in gymnosperms and angiosperms."
- **Analysis**: This statement is correct as both gymnosperms and angiosperms exhibit a diplontic life cycle.

- **Statement 3**: "Most algal genera are haplontic."
- **Analysis**: This statement is also correct as many algae, particularly green algae, have a haplontic life cycle.

- **Statement 4**: "Haploid spores divide by mitosis to form a haploid plant body."
- **Analysis**: This statement is correct since haploid spores undergo mitotic division to develop into a haploid organism.

3. **Conclusion**:
- The incorrect statement is the first one: "Haplontic life cycle is found in Volvox, Fucus, and Spirogyra" because Fucus has a diplontic life cycle.

### Final Answer:
The incorrect statement is: **"Haplontic life cycle is found in Volvox, Fucus, and Spirogyra."**

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