C.
Every change in a species is coded within the DNA. But the bird had lost a toe an accident. So the toe-loosing-option isn't true because not every bird looses his toe.
(Example: If a women gets bitten by a snake on the arm and gets the arm removed from her body and then in a year or so has a baby with her new husband. The baby won't be born with one arm because his/her mother lost her arm.) <span />
Answer: Most viruses can use host machinery to produce more of themselves
Explanation:
Since viruses carry out no metabolism themselves, they rely solely on the living cells of the host (organism they infect) to replicate and spread from cell to cell.
Thus, viruses do not kill the cells they infect since they need them, and use them to replicate more offsprings
Although all cells have the same DNA only some parts of it are turned on depending on what the cell needs to do, so each cell turns on different parts of itself depending on what its job is.
Hope this helps!
