Marble and slate are examples of impermeable rocks.
The function of the cell membrane is to protect the cell from any outer surroundings that could be harmful to it.
If you do not have variations to be selected by natural or sexual selection on their superior abilities to survive and reproduce successfully then nothing can be naturally selected against the immediate environment.
Answer;
-Oxygen
Explanation;
Both the glucose and oxygen produced in photosynthesis are used in aerobic respiration.
-Photosynthesis makes the glucose that is used in cellular respiration to make ATP. The glucose is then turned back into carbon dioxide, which is used in photosynthesis.
-While water is broken down to form oxygen during photosynthesis, in cellular respiration oxygen is combined with hydrogen to form water.
