1. Nitrogenous Bases: These are the building blocks of the genetic code, providing the information carried by DNA. There are four types of nitrogenous bases:

* Adenine (A)

* Guanine (G)

* Cytosine (C)

* Thymine (T)

2. Deoxyribose Sugar: This is a five-carbon sugar molecule that forms the backbone of the DNA strand. It is called deoxyribose because it lacks an oxygen atom on the second carbon.

3. Phosphate Group: This is a negatively charged group that also forms part of the DNA backbone. It connects the deoxyribose sugars of adjacent nucleotides.

These three components come together to form nucleotides, which are the monomers of DNA. Each nucleotide consists of one nitrogenous base, one deoxyribose sugar, and one phosphate group.