DENDROLOGY

Detailed explanation-1: -Algae, along with plants and some bacteria and fungi, are autotrophs. Autotrophs are the producers in the food chain, meaning they create their own nutrients and energy. Kelp, like most autotrophs, creates energy through a process called photosynthesis.

Detailed explanation-2: -No, all plants are not autotrophic. Some of the non-green plants such as dodder plants obtain their food from other plants and these plants are heterotrophic plants. Heterophic plants generally do not possess chlorophyll, which inhibits their ability to prepare their own food.

Detailed explanation-3: -Because they derive their energy directly from the sun to produce food for themselves.