Questions: Why are ducks important to freshwater biomes? They clean the water surface. They spread plant seeds. They provide food for plants. They are not important.

The answer is the second one: They spread plant seeds.

Explanation for each option:

1. They clean the water surface. - While ducks may occasionally eat algae or small debris, their primary role is not cleaning the water surface. This option is not the most accurate description of their ecological role.

2. They spread plant seeds. - Ducks play a significant role in seed dispersal in freshwater biomes. As they move from one area to another, seeds can attach to their bodies or be ingested and later excreted, helping to spread plant species across the biome.

3. They provide food for plants. - This option is incorrect as ducks do not provide food for plants. Instead, they are more involved in the ecosystem as consumers rather than as a direct food source for plants.

4. They are not important. - This option is incorrect. Ducks are important to freshwater biomes for various reasons, including their role in seed dispersal and as part of the food web.

In summary, ducks are important to freshwater biomes primarily because they help in spreading plant seeds, contributing to the biodiversity and health of these ecosystems.