he answer is because <span>samples of air taken over erupting volcanoes shows that volcanoes
contribute a small amount of chlorine in the stratosphere compared to CFCs. Volcanic
eruptions account for a large instability of chlorine from land to the
atmosphere on a yearly basis. This is in addition to chlorine that enters the
atmosphere from sea spray, industrial processes and biological gases which are
from CFCs. All of these inputs happen near or at the base of the atmosphere. Very
little of the material emitted from volcanoes makes it up into the upper
reaches of our atmosphere which is the stratosphere where it could touch the
ozone layer. However, most of it is believed to be deposited lower down which
is in the troposphere, where it then rained out back to the surface of the
earth.</span>
The answer is (d.) Some scientists believe that prions, tiny proteins much smaller than a cell, that can replicate themselves may be living organisms.
Prions are like viruses, they are not alive making statement B to be true. Prions lack the ability to grow and reproduce. they are dependent on the living cells to replicate. Statement A is absolutely correct while Statement C is somehow wrong. According to scientists, the accurate count of cells in a human is 37.2 Trillion.
The role a species plays in the ecosystem is called its niche.
