Which of the following statements is true for pollination by water ?

Options

A. Pollen grains of water pollinated plants are small and spherical .
B. The flowers of water pollinated plants are not very colourful.
C. Female flowers of Vallisneria remain submerged in water and male flowers release the pollen inside the water causing pollination deep with water .
D. Nelumbo nucifera (India lotus) is an aquatic plant pollinated by water.

Answer

To determine which statement is true for pollination by water, we will analyze each statement provided in the question.

### Step-by-Step Solution:

1. **Analyze Statement 1**: "Pollen grain of water pollinated plants are small and spherical."
- This statement is incorrect. Pollen grains of water pollinated plants are typically long and ribbon-like, which helps them to be carried by water currents.

2. **Analyze Statement 2**: "The flowers of water pollinated plants are not very colorful."
- This statement is correct. Water-pollinated plants generally do not have brightly colored flowers because they do not rely on visual attraction for pollination. Instead, they depend on water currents to transport pollen.

3. **Analyze Statement 3**: "Female flower of Valisneria remain submerged in water and male flower release the pollen inside the water causing pollination deep with water."
- This statement is incorrect. In Valisneria, the male flowers have long stalks that reach the surface of the water, where they release pollen. The female flowers are submerged, but the pollination occurs at the water's surface, not deep underwater.

4. **Analyze Statement 4**: "Nalumbo nusifera that is Indian lotus is an aquatic plant pollinated by water."
- This statement is incorrect. The Indian lotus (Nelumbo nucifera) is primarily cross-pollinated by insects, not by water.

### Conclusion:
The only true statement regarding pollination by water is **Statement 2**: "The flowers of water pollinated plants are not very colorful."

### Final Answer:
**The correct answer is Statement 2.**

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