<span>S phase is the duplication of the cells genetic information, if this did not occur, when the cell divides into two cells, there would be no copy of this genetic information given to 1 out of the 2 cells.
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The hole reason for natural selection is to keep the Eco system in balance take something away it will fall apart or if you put to much of something the same thing will happen.
Fertilizers can make their way into water sources when it rains and when the fertilizer makes it into a lake, the harsh chemicals from the fertilizer will pollute the water.
The answer is Sensory Neurons