Intergenic DNAseparates the genes from one another. In the case of a virus
genome the genes are packed very closely and therefore these intergenic regions
are very low or almost nil. In higher organisms the genes are more spread out and
are usually separated by very long intergenic regions. Intergenic regions are
comparatively less in the case of prokaryotes. The number of genes varies greatly
from organism to organisms. E. colicarries approximately 2,400 genes, yeasts with
16 chromosomes have about 6,600 genes. It is estimated that the human genome
contains about 30,000 to 35,000 genes. But it forms only about 2 to 3% of the total
DNA. The remaining major parts of the DNA are non-coding and non-functional,
consisting of various types of repeated intergenic regions. In addition to these