Question

Regarding the assertion and reason, select the correct option.

Assertion [A]: A polynucleotide chain exhibits polarity.
Reason [R]: At one end of the polynucleotide chain, a phosphate group is found attached to the fifth (5’) carbon of the sugar ring (of the respective nucleotide), and at other end, a free 3’ -OH group is present.

• A. Both A and R are true and R explains A
• B. Both A and R are true, but R does not explain A
• C. A is true and R is false
• D. Both A and R are false

Answer 1

The correct option is A

Both A and R are true and R explains A

In a polynucleotide chain, a phosphate group is found attached to the fifth (numbered 5') carbon of the sugar ring, and at the other end, a free 3’ -OH group is present. This gives the chain a 5’ end and a 3’ end respectively, resulting in polarity.