Answer:
Then what is the question???
Explanation:
Echinoderms get their food and oxygen for energy. They use tube feet to obtain from the water. The tiny tube feet are involved in passing collected food towards the central mouth.These animals are detritivores performing similar functions to earthworms on the land in recycling nutrients.
The answer is <span>provide basis of food chains.
</span><span>Plankton includes a diverse group
of organisms that live in the water, but are not capable of active
swimming against the current. They are usually present in the upper part of the ocean, where is enough sunlight.
They are the basis of food chains in water ecosystems. They provide food for different animals, such as jellyfish, shrimps, whales, etc. </span>