Question

Deoxythymidine is a monomer nucleotide of DNA
A. True
B. False

Answer 1

Nucleotides are compounds consisting of a nucleoside linked to a phosphate group. Nucleotides form the basic structural unit of nucleic acids such as DNA.

Complete answer:
DNA is a long polymer of deoxyribonucleotides.The length of the DNA is usually defined by the number of nucleotides present in it.

A nucleotide has three components – a nitrogenous base ,a pentose sugar ( deoxyribose in case of DNA ,where is ribose in case of RNA ) and a phosphate group.

There are two types of nitrogenous bases – Purines which include Adenine and Guanine , and the second type of nitrogenous base is pyrimidines which include cytosine and thymine ( uracil instead of thymine in case of RNA ).

A nitrogenous base is linked with pentose sugar through a N-glycosidic linkage to form a nucleoside, such as adenosine or deoxyadenosine ,cytidine or deoxycytidine ,guanosine or deoxyguanosine and uridine or deoxythymidine.

Hence, the correct answer is option (A)

Note: When a phosphate group is linked to 5’-OH of a nucleoside through phosphodiester linkage ,a corresponding nucleotide (or deoxynucleotide) is formed.Two nucleotides are linked through 3’-5’phosphodiester linkage to form dinucleotide. The backbone in the polynucleotide chain is formed due to sugar and phosphates.