Molecular Basis of Inheritance — BIOLOGY STD 12 Science — Question

4. Are antiparallel

Explanation:

Quaternary structure of the protein refers to the number and arrangement of multiple folded protein subunits with respect to each other to form a multi-subunit complex; it does not include any molecule other than polypeptide chains. Quaternary structure of DNA refers to the organization of DNA into chromatin via histone octamers to arrange it into a condensed structure; statement A is incorrect.

Each nucleotide base of one strand is paired, via a hydrogen bond, in the same plane with a base of the other strand thereby joining two strands together; statement B is incorrect.

The same orientation of all phosphodiester linkages along the chain imparts each linear nucleic acid strand a distinct polarity and distinct 5’ and 3’ ends; statement C is incorrect.

The 5’ end lacks a nucleotide at the 5’ position thereby having free phosphate group and the 3’ end lacks a nucleotide at the 3’ position thereby having a free hydroxyl group. The two DNA strands are antiparallel means that 5’ end of one strand faces 3’ end of other strand and vice versa.