Question

In a bacterium, the amount of Adenine was found to be $18$ percent. Suggest the cytosine base composition from the following.

• A. $64\%$
• B. $36\%$
• C. $32\%$
• D. $18\%$

Answer 1

The correct option is C $32\%$

According to Chargaffs rule,

(Adenine+ Thymine) + (Guanine + Cytosine) = 100%

Adenine binds with thymine

So the number of Adenine = Thymine

Therefore, thymine = 18 %

Guanine + Cytosine= 100-(18+18) % =(100- 36) % = 64%

Guanine binds with cytosine

So Guanine = Cytosine

Therefore Cytosine= 64/2 % = 32%

So the correct answer is option C.