All cells are surrounded by a cell membrane that separates the cell from the outside environment. The cell membrane is selectively permeable, which means...
Answer
some substances can pass through the membrane while others cannot.
oxygen and food come in, while waste materials go out.
all substances can pass through it.
it can hear most things but not if they are homework related.
Question 2
Question
Pretend the red dots are oxygen molecules. What process is illustrated?