In Spirogyra, asexual reproduction takes place by

Options

A. breaking up of filaments into smaller bits.
B. division of a cell into two cells.
C. division of a cell into many cells.
D. formation of young cells from older cells.

Explanation

**Step-by-Step Solution:**

1. **Understanding Spirogyra**: Spirogyra is a filamentous green algae that reproduces both sexually and asexually. Asexual reproduction is a method where new individuals are produced without the fusion of gametes.

2. **Identifying Asexual Reproduction Methods**: The question presents several options for how asexual reproduction occurs in Spirogyra:
- A) Breaking up of filaments into smaller bits
- B) Division of a cell into two cells
- C) Division of a cell into many cells
- D) Formation of young cells from older cells

3. **Analyzing the Options**:
- **Option A**: Breaking up of filaments into smaller bits is known as fragmentation. In Spirogyra, the filament can break into smaller segments, each of which can develop into a new individual.
- **Option B**: Division of a cell into two cells is more characteristic of binary fission, which is not the primary method of asexual reproduction in Spirogyra.
- **Option C**: Division of a cell into many cells is not a typical method of asexual reproduction in Spirogyra.
- **Option D**: Formation of young cells from older cells does not accurately describe the asexual reproduction process in Spirogyra.

4. **Conclusion**: The correct method of asexual reproduction in Spirogyra is through fragmentation, where the filament breaks into smaller pieces, and each piece can grow into a new filament. Therefore, the correct answer is **A) Breaking up of filaments into smaller bits**.

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