I agree because an ecosystem and a host are basically the same thing.
Answer:
an aquatic ecosystem is an ecosystem in the body of water examples are marine ecosystem and fresh water ecosystem
The cell in the middle differs from its surrounding cells by having a double cell membrane hence the cells do not have the exact same structure and most likely do not come from the same cell. For cells to produce food molecules, I am not too sure but I feel that the question is referring to plant cells that are able to photosynthesize. Plant cells have a cell wall and a cell membrane hence is unlikely to be represented by most of the cells in this diagram. Thus by elimination, the answer could be having the same function
