Question

Nucleic acids are polymer of:
A. Nucleotides
B. Nucleosides
C. Nuclei of heavy metal
D. Proteins

Answer 1

Hint:Chromosomes, the particles responsible for heredity are made up of protein,nucleic acid. Nucleic acids are of two types.
-Deoxyribonucleic acid (DNA)
-Ribonucleic acid (RNA)

Complete step by step answer: A nucleic acid is a biopolymer i.e., polymers present in the living system. They are also called as polynucleotides since the repeating structural unit of nucleic acid is a nucleotide. Each nucleotide is made up of three parts i.e., a sugar molecule, a heterocyclic nitrogenous base, and a phosphoric acid. In general, a nucleotide may be represented as shown below:

Hence the nucleic acid may be represented as below:

 Chemical composition of nucleic acid contains:
-A pentose sugar
-The nitrogen-containing heterocyclic compound also called nitrogenous base
-Phosphoric acid
So, the correct answer is “Option A”.

Additional Information: The structure of nucleic acid is discussed at the following two levels:
-Primary structure: The sequence in which the four nitrogen bases are attached to the sugar-phosphate backbone of a nucleotide chain is called the primary structure.
-Secondary structure: Secondary structure of nucleic acid is the set of interactions between bases. In DNA double helix, the two strands of DNA are held together by a hydrogen bond, the nucleotides on one strand base pair with the nucleotide on the other strand. It is responsible for the shape taken by the nucleic acid. In the case of RNA, its secondary structure consists of a single polynucleotide. Base pairing in RNA occurs when RNA folds between the complementarity regions.

Note: There are two different class of nitrogenous base found in nucleic acid:
Purines: the two purines which are most commonly found in nucleic acid are adenine (A) and guanine (G).
Pyrimidines: There are three most commonly occurring pyrimidines in nucleic acid.
-Uracil (U)
-Thymine (T)
-Cytosine (C)