Question

Nitrogen base + Pentose sugar + Phosphate group is
A. Nucleoside
B. Nucleic acid
C. Pyrimidine
D. Nucleotide

Answer 1

Hint: DNA and RNA are the two most important nucleic acid structures present in the chromosome of the cell. These are two structures that are the main genetic material in almost all living organisms and are responsible for carrying the genetic information from the parents to the next generations.

Complete step by step answer: DNA or deoxyribonucleic acid and RNA or ribonucleic acid is mainly responsible for the genetic information transfer from the parents to the next generation. They are present in the chromosome of the cell. DNA is a double helical structure consisting of two intertwining strands. RNA has a single circular structure. DNA and RNA are composed of molecules called the nucleotide.
Nucleotides are one type of organic molecules which consist of a nucleoside and a phosphate. They act as monomeric units of the nucleic acid polymers like deoxyribonucleic acid or DNA and ribonucleic acid or RNA. Both of these nucleic acids are important biomolecules to form life on the earth.
Generally, nucleotides are made up of three subunit molecules and those are a nitrogenous base which is also known as nucleobase, a sugar with five-carbon i.e. ribose or deoxyribose, and eventually a phosphate group which consisting of one to three phosphates. There are four nitrogenous bases present in DNA and they are guanine, adenine, cytosine, and thymine. In the case of RNA, thymine is replaced by the uracil.
Nucleotides also play a major performance in metabolism by providing chemical energy in the form of ATP. Nucleotides take part in cell signalling and corporates into enzymatic reactions.
Nucleoside is the combination of only nitrogen base and pentose sugar. There is no phosphate group present in the nucleoside. The nucleic acid is the polymer made up of the nitrogen bases.
THe pyrimidine bases are one of the heterocyclic nitrogenous bases that are found in the DNA and the RNA. In DNA, thymine and cytosine are the pyrimidine bases present and in RNA, uracil is present in place of thymine.
Therefore, the correct option is option D.

Note: Nucleotides are the organic molecules which consist of nucleoside and phosphate groups. It is the monomeric unit of nucleic acid i.e. the polymers of nucleotides are known as nucleic acid. A nucleotide is made up of three specific chemical subunits which are a five-carbon sugar molecule which is called pentose, a nitrogenous base, and one phosphate group.