Answer:
It's 3!
Explanation:
There must be genetic differences so the best fitted organisms will survive. If they were all the same then no one would be best fitted and Natural Selection wouldn't be able to occur
It's not 1 because a food shortage isn't required, there's always competition for food sources
It's not 2 because there doesn't need to be a change in the environment for natural selection, just for evolution.
And it can't be 4 if 1 and 2 are wrong!
Hope this helped!
Skeletal and Muscular Systems
If a higher concentration of salt is placed outside of the cell membrane, the water will leave the cell to bond with it. The loss of water from this movement causes plant cells to shrink and wilt.
Outputs : Oxygen
Inputs: Sunlight;Carbon dioxide;Water
