The answer is (1) !!
it is one direction, from sun to produces to consumer !!
The first three are the same as those found in DNA, but in RNA thymine is replaced by uracil as the base complementary to adenine. This base is also a pyrimidine and is very similar to thymine. Uracil is energetically less expensive to produce than thymine, which may account for its use in RNA.
Answer:
The nitrogenous bases in DNA are adenine (A), guanine (G), thymine (T), and cytosine (C).
Explanation: