<span>I believe it is light, but this is kind of a confusing question. Technically there is a independent and dependent variable in the question. The variable being manipulated is light, and the earthwork activity depends on the light. </span>
I would go with c because its tells you right in there that the ecosystem help who lives around that area.
A - Viruses cannot survive outside of a host whereas bacteria can.
Sperm and egg cells do not go through mitosis, they go through meiosis. Why? Well, in mitosis, cells copy themselves. But in sperm and egg cells, they have to duplicate differently. So, there is no such thing as two different sperm or egg cells that are the same.