What is the structural unit of DNA?

DNA:

1. DNA, also known as deoxyribonucleic acid, is made up of two strands that are positioned in opposition to one another.
2. Repeating subunits with nitrogenous bases, sugar, and phosphate groups make up each DNA chain.
3. DNA is made up of monomeric molecules called nucleotides.
4. A nitrogenous base, a phosphate group, and sugar make up each nucleotide.
5. Purines and pyrimidines are the two different kinds of nitrogenous bases. The sugar is either ribose or deoxyribose.