Chapter 12, Problem 27A

Summary Introduction

Introduction:

Each DNA molecule consists of two strands. Both the strands have complementary base pairs. During transcription, the two strands of DNA unwind. One strand serves as a template to synthesize new mRNA molecule while the other strand that remains unused is called the non- template strand.

Answer to Problem 27A

Correct answer :

The correct answer is option A. 5’ ATGTTTGATCTT3’.

Explanation of Solution

Explanation/justification for the correct answer:

Option A. 5’ATGTTTGATCTT3’- The non-template strand of DNA will move in a 5’ to 3’ direction and will have complementary base pairs to the given template strand. Adenine will pair with thymine and cytosine will pair with guanine.

Hence, this is the correct option.

Explanation for incorrect answer:

Option B. 5’AUGUUUGAUCUU3’- Uracil is incorporated instead of thymine as the mRNA molecule is made. In the non- template strand of DNA, adenine will pair with thymine; there will be no uracil. Hence, this is not the correct option.

Option C. 5’TACAAACTAGAA3’- The non-template strand of DNA will move in a 5’ to 3’ direction and will have complementary base pairs to the given template strand. Adenine will pair with thymine and cytosine will pair with guanine. Hence, this is not the correct option.

Option D. 5’UACAAACUAGAA3’- There will be no uracil in the non- template strand of DNA. Adenine will pair with thymine. Hence, this is not the correct option.