Well for both of them to survive they need oxygen, food, water amino acids, and a way to leave waste, but that depends on the type of cell
If later is was 100 million years ago, later b would be 200 million years ago (because it is 100millions years prior to a). And therefore layer c must b 300 million years ago.
B cells mature in the bone marrow, which is at the core of most bones It recognises invaders by the shape of molecules -antigens- on their surfaces. With the help of T cells, B cells make proteins called antibodies. The antibodies will help your body become aware of intruders.
Answer:
4.Cell wall protects the cell whiles organelles are found in the cell itself which is having the cell wall
