Question

While analyzing the DNA of an organism, a total number of 5386 nucleotides were found out of which the proportion of different bases were Adenine = 29%, Guanine = 17%, Cytosine = 32%, and Thymine = 17%. Considering Chargaff’s rule, it can be concluded that

It is single-stranded DNA.

It is double-stranded linear DNA.

No conclusion can be drawn.

It is a double-stranded circular DNA.

• A. It is single-stranded DNA.
• B. It is a double-stranded linear DNA.
• C. No conclusion can be drawn.
• D. It is a double-stranded circular DNA.

Answer 1

The correct option is (A):

Explanation of the correct option:

1. The given DNA cannot be a double-stranded DNA.
   
2. Chargaff's rule states that the ratios between adenine and thymine and guanine and cytosine are constant and equal.
   
3. Here, we are getting adenine as 29% but thymine as 17%, which must be equal in a double stranded DNA.
   
4. This is why, the sequence given here depicts a single stranded DNA.

Final Answer: Considering Chargaff's rule, it can be concluded that it is a single-stranded DNA.