Chapter 12, Problem 4A

Summary Introduction

Introduction :

Erwin Chargaff studies the amount of adenine, guanine, thymine, and cytosine in the DNA of various species. Base on the data, Chargaff found that the amount of Guanine (G)is almost equal to the amount of Cytosine (C) and the amount of Adenine (A) nearly equals the amount of Thymine (T) within a species.

Answer to Problem 4A

Correct answer :

The correct answer is option (B) 27 percent.

Explanation of Solution

Explanation/justification for the correct answer :

Option (B) 27 percent.A according toChargaff rule: C = G and T = A. Therefore, if in a section of DNAthe percentage of thymine is 27 then the adenine percentage will also be 27. Thus, the correct answer.

The explanation for the incorrect answer :

Option (A) 23 percent. It is less than the given thymine percentage which is incorrect. Thus, this is an incorrect option.

Option (C) 46 percent. It is more than the given thymine percentage which is incorrect. Thus, this is an incorrect option.

Option (D) 54 percent. It is double than the given thymine percentage which is incorrect. Thus, this is an incorrect option.