Cytosine (C) and thymine (T) are the smaller pyrimidines. RNA also contains four different bases. Three of these are the same as in DNA: adenine, guanine, and cytosine. RNA contains uracil (U) instead of thymine (T).
Answer:
B
Explanation:
End Ordovician
Late Devonian
End Permian
End Triassic
End Cretaceous
d. All of the above
Explanation: is correct
