Which of the following pairs describes seeds that are likely to be dispersed by water?

The correct choice is associated with seeds that are light and buoyant, which allows them to float on water. This characteristic is crucial for water dispersal because buoyant seeds can travel long distances on the surface of water bodies. Many aquatic plants and those that grow near water rely on this method of seed dispersal to reach new areas suitable for germination.

Buoyant seeds are often designed with air pockets or a lightweight structure that helps them stay afloat, making it easier for them to be transported by water currents. This adaptation not only enhances the chances of reaching suitable habitats for growth but also helps in reducing competition with the parent plant.

In contrast, the other options describe seed characteristics that would not favor water dispersal. Heavy and firm seeds, for example, would sink quickly and not travel well through water. Sticky and moist seeds are more suited for attachment to animals or objects rather than floating. Small and dry seeds may disperse by wind rather than water, as their lightweight nature does not lend itself to buoyancy in a liquid environment.