Ulothrix is

Options

A. Attached unbranched filament
B. Attached branched filament
C. Colonial alga
D. Free floating.

Answer

**Step-by-Step Text Solution:**

1. **Definition of Ulothrix**: Ulothrix is a genus of filamentous green algae. It is commonly found in both marine and freshwater environments.

2. **Structure of Ulothrix**: The algae consist of unbranched filaments. Each filament is made up of individual cells that are typically as broad as they are long.

3. **Cellular Composition**: Each cell in Ulothrix has a distinct nucleus and a central vacuole. The chloroplasts are thin and contain at least one pyrenoid, which is involved in starch storage.

4. **Attachment Mechanism**: Ulothrix has specialized cells known as holdfasts that enable it to attach to surfaces. This adaptation allows it to anchor itself to the bed of freshwater streams, rivers, and even wet cliffs or damp soil.

5. **Environmental Preferences**: Ulothrix thrives in cooler temperatures, particularly during spring and winter. This preference for low temperatures contributes to its growth patterns.

6. **Summary**: In summary, Ulothrix is an attached, unbranched filamentous green algae that thrives in freshwater and marine environments, characterized by its specialized attachment cells and preference for cooler temperatures.

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