That is, Chromosome 1, with the smallest number, is actually the largest chromosome. It has almost 3,000 genes on it. And we go down to the smallest chromosomes, the ones with the largest numbers.

Is chromosome big or small?

Our genetic information is stored in 23 pairs of chromosomes that vary widely in size and shape. Chromosome 1 is the largest and is over three times bigger than chromosome 22. The 23rd pair of chromosomes are two special chromosomes, X and Y, that determine our sex.

Is a gene or chromosome smaller?

Chromosomes contain smaller units of genetic material called DNA. DNA is a sequence of letters that spell out the genetic code. The DNA is organized into words and sentences called genes.