Viruses need to be inside a living thing (of course the living thing has to have the right temperature which most living things do) . When they're inside a living thing they start injecting the host's cells with its DNA in order to make more copies of itself which allows the virus to spread. So basically viruses need to be inside something living.
The inner planets are made of rocks while the outer planets are composed of gas.
The inner planets are closer to Sun and are small in size while the outer planets are far away from sun and are larger in size
MITOSIS is used to generate more cells. It is a kind of cell division that the new cells are identical.
