What describes filamentous algae?

Filamentous algae are characterized by their appearance, which often resembles wet cotton or hair. This type of algae typically forms long, thread-like structures that can attach themselves to various surfaces in aquatic environments, such as rocks, plants, or even artificial structures. This attachment helps them gather nutrients and sunlight for photosynthesis while remaining partially submerged in the water.

In contrast, rooted algae would suggest a different form of growth, more characteristic of higher plants than filamentous forms. Growth that occurs completely submerged may describe other algae or aquatic plants, but filamentous algae can be found both submerged and attached. Floating types of algae suggest a different lifestyle where the algae do not have attachment points and instead drift freely in the water. Each of these incorrect options highlights different characteristics that do not align with the defining traits of filamentous algae, further emphasizing the unique structure and behavior of this type of algae.