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:
Complementary RNA (cRNA) is a copy of a strand of RNA that will bind to the appropriate region of the original molecule. If the original RNA stand had a base sequence of AUU, for example, the sequence of the cRNA strand would be UAA.
Hope it helps.
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