Basal cell of Ulothrix is

Options

A. Extra green
B. Colourless
C. Full of reserve food
D. Without a nucleus.

Answer

**Step-by-Step Solution:**

1. **Understanding the Structure of Ulothrix:**
- Ulothrix is a type of green algae that consists of unbranched, uniseriate filaments. Each filament is made up of cells arranged end to end.

2. **Identifying the Basal Cell:**
- The basal cell is the cell located at the base of the filament. It is important to note that this cell has specific characteristics that differentiate it from other cells in the filament.

3. **Characteristics of the Basal Cell:**
- The basal cell is elongated in shape.
- It lacks chlorophyll, which is the pigment responsible for the green color in plants. This absence of chlorophyll means that the basal cell does not exhibit a green color.

4. **Function of the Basal Cell:**
- The basal cell is also known as the "holdfast." Its primary function is to anchor the filament to the substratum (the surface it grows on).

5. **Conclusion:**
- Given the characteristics of the basal cell, the correct answer to the question is that the basal cell of Ulothrix is "colorless" due to the lack of chlorophyll.

**Final Answer:**
The basal cell of Ulothrix is colorless because it lacks chlorophyll.

---