Select the statement that is not correct.

Options

A. In aquatic plants like water hyacinth, pollination is carried out by insect or wind
B. In Vallisneria , the male flowers reach the surface of the water by a long stalk to liberate pollen grains.
C. In seagrasses , female flowers remain submerged in water.
D. Vallisneria and Hydrilla grow in freshwater while Zostera grows in seawater.

Answer

To solve the question, we need to evaluate each statement provided and identify which one is incorrect.

1. **Statement 1**: "In aquatic plants like water hyacinth, pollination is carried out by insect or wind."
- Water hyacinth is indeed an aquatic plant, and its flowers emerge above the water surface, allowing for pollination by insects or wind. This statement is correct.

2. **Statement 2**: "In Valesneria, the male flowers reach the surface of water by a long stalk to liberate pollen grains."
- This statement is incorrect. In Valesneria, it is the female flowers that reach the surface of the water via a long stalk, while the male flowers release pollen grains that are carried by water currents to the female flowers. Thus, this statement is the one that is not correct.

3. **Statement 3**: "In seagrasses, female flowers remain submerged in water."
- This statement is correct. In seagrasses, the female flowers are indeed submerged, and the male pollen grains are released into the water.

4. **Statement 4**: "Valesneria and Hydrilla grow in freshwater while Zostera grows in seawater."
- This statement is also correct. Valesneria and Hydrilla are freshwater plants, while Zostera is a seagrass that grows in seawater.

After evaluating all the statements, we find that the second statement is the one that is not correct.

**Final Answer**: The incorrect statement is option 2: "In Valesneria, the male flowers reach the surface of water by a long stalk to liberate pollen grains."