Which chromosomes carries the fewest number of genes

The absence or presence of the y chromosome determines the sex of a human being. the y chromosome pairs up with the x chromosome; this pair is called the sex chromosomes. men have an x and a y chromosome. when a man makes sperm cells, the y chromosome, because it has fewer genes than the x chromosome, cannot exchange genetic material with its partner. the y chromosome, therefore, passes from one male generation to the next male generation in a relatively unchanged form. the x chromosome is much larger than the y chromosome. a woman possesses two x chromosomes. when her body forms egg cells, pieces of each x chromosome break off and recombine to create new genetic combinations