The disappearance of the deer from the forest indicates the EXTINCTION OF THE DEER.
The extinction of the deer from the forest will throw the ecosystem out of balance and has negative impacts on the ecosystem. After all the deer has been eliminated, the elephants too will either have to find another source of food or be wiped out.
The answer is cell division
In living organisms, cell division is the means by which development and growth take place. The survival of the living cells depend on interaction with other cells. The process of cell division in developmental stages of growth involves round of cell divisions during which the cell become increasingly more specialized and organize in certain pattern. This interaction during this stage mold the overall morphology of the organism.
D. Most organisms have teeth