Question

Suppose the first nucleotide on a codon is adenine. What will the first nucleotide be on the corresponding anticodon?

Answer 1

The codon is found on the messenger RNA molecule and is complementary to the anticodon on the transfer RNA molecule. The base pairing in RNA molecules is:

Adenine with Uracil (because RNA molecules do not have Thymine)
Cytosine with Guanine

This means that the first nucleotide on the anticodon will be uracil.