The number of DNA molecules in each chromosome is

A single chromosome contains only one DNA (deoxyribonucleic acid) molecule and so many genes.
Humans have 23 pairs of chromosomes.
22 pairs of autosomes chromosomes and one pair of sex chromosomes, X and Y.

🛑Important Points:
In the cell nucleus, the DNA molecule is packaged into thread-like structures called chromosomes.
A chromosome (microscopic structure) is made up of DNA tightly coiled many times around proteins called histones that support its structure.
A chromosome has two arm – p arm (short arm) and q arm (long arm), joined in the location of the centromere.

🔑Key Points:
The information in DNA (double helix structure) is stored as a code made up of four chemical bases: adenine (A), guanine (G), cytosine (C), and thymine (T).
DNA has two base pairs, A-T and G-C, attached to a sugar-phosphate backbone.