Animals, they only have a cell membrane, not cell walls.
I don't know what the answer choices were, though, but I hope this helps.
Answer:
D. organ systems
Explanation:
Organs and tissues that perform the same function are called organ systems
Answer: A community is all of the populations of different species that live in the same area and interact with one another. A community is composed of all of the biotic factors of an area. An ecosystem includes the living organisms (all the populations) in an area and the non-living aspects of the environment.
