Answer:
A
Explanation:
In such an isolated ecosystem, there is usually an autotroph species that coverts the abiotic elements in the environment to biotic elements. In a hydrothermal vent, it is likely that there are some chemoautotrophic bacteria that covert the sulfur and other chemicals in the water into organic molecules. This energy is then transferred up the food web in the closed ecosystem. In such an ecosystem, even the waste product of one life form may be utilized by another species.
The function of the digestive system<span> is </span>digestion<span> and absorption.</span>Digestion<span> is the breakdown of food into small molecules, which are then absorbed into the body. The </span>digestive system<span> is divided into two major parts: The </span>digestive tract<span> (alimentary canal) is a continuous tube with two openings: the mouth and the anus.</span>