Question

Which nitrogen bases are needed to complete the DNA strand pictured below? Give your answer in order from top to bottom.


cytosine, thymine, cytosine, guanine


cytosine, thymine, guanine, guanine


thymine, cytosine, thymine, adenine


adenine, cytosine, adenine, guanine

Answer 1

Answer: Cytosine, Thymine, Cytosine, Guanine (option A)

Explanation:

In DNA strands, you must use base-pairing rules to complete strands.

The base-pairing rules are:

Adenine (A) bonds with Thymine (T)

Guanine (G) bonds with Cytosine (C)

By using these rules, you can pair the sequence GAGC with CTCG

The sequence CTCG is also represented as the bases Cytosine, Thymine, Cytosine, and Guanine, making A the correct answer.

I hope this helps!