Two main factors :
First, the distance from the earth to the sun allows enough heat (energy), not too much, to be absorbed on earth's surface.
Second, earth's atmosphere allows it to keep most of the heat it absorbed during the day for the night. Otherwise, temperatures would drop down below a life sustaining point.
<u>Answer:</u>
The cell differentiation is necessary for the survival of multi-cellular organisms because at the beginning all the organisms start from a single cell called the zygote. This zygote undergoes mitosis and forms many uniform cells that do not have any specific function.
The differentiation of these cells is required for the development of specific organs and organ systems from this single cell.Cell differentiation is an essential process that gives a specific function to the cells of the body.
