Dna is made of repeating units called

DNA is made of repeating units called nucleotides.

Explanation:

DNA can be described as a double helix molecule made up of long polymer chains of nucleotides. The nucleotides which are present in a DNA are:

Adenine (A)

Guanine (G)

Cytosine (C)

Thymine (T)

The hydrogen bonds which occur in the pairing of nucleotides makes the double helix structure of DNA.

Adenine forms hydrogen bonds with Thymine.

Guanine forms hydrogen bonds with Cytosine.

The backbone of the DNA is made up of sugars and phosphates

when atoms of different types of elements join together, they make molecules called compounds. water consists of compound molecules made up of 2 hydrogen atoms and 1 oxygen atom. this is why it's called h2o. water will always have 2 times the number of hydrogen atoms as oxygen atoms.