Question

DNA is made up of three different molecules: the sugar deoxyribose, a phosphate group, and a nitrogenous base. The basic unit of the DNA, the NUCLEOTIDE, is made up of each one of these. A molecule of DNA may contain as many as 200,000 nucleotides. The nucleotides make up two chains that are linked and twisted around one another in the form of a double helix.A. What is the basic unit of the DNA molecule?B. Name each of the components of this unit.

Answer 1

A. The basic unit of the DNA molecule is the nucleotide.

B. The nucleotide is composed of three parts. Its components are:

- a sugar (ribose in RNA or deoxyribose in DNA)

- a phosphate group and

- a nitrogen-containing base (it can be Adenine, Cytosine, Guanine or Thymine in DNA - in RNA Thymine is replaced by Uracil).