Unicellular organisms don't have membrane bound organelles
Cells are combined in a structure called tissue wich have the same properties like the cells wich are formed by.
In the stomach i think or lungs
Answer:
A producer. For example in a common food chain, grass->grasshopper->mouse->snake->eagle. The grasshopper eats grass which is a producer so if there aren't anymore insects like grasshoppers, then the grass grows more.