The nucleotide bases of ribonucleic acid (RNA) form base pairs following specific rules for pairing together that never change, such as which of the following?

Question

Thymine pairs with cytosine.

Uracil pairs with cytosine.

Uracil pairs with guanine.

Guanine always pairs with cytosine.

Answer 1

In RNA, the specific pairing rules for nucleotide bases are as follows:

• Adenine (A) pairs with Uracil (U).
• Guanine (G) pairs with Cytosine (C).

Among the options you provided, the correct statement is:

Guanine always pairs with cytosine.

The other pairings mentioned (Thymine with cytosine, Uracil with cytosine, and Uracil with guanine) are not correct according to the standard base pairing rules in RNA.