what do different genes control
. Different genes control the development of different characteristics of an organism. Many genes are needed to carry all the genetic information for a whole organism. Nucleus, chromosome and gene. The number of genes and chromosomes varies from species to species.hromosomes and genes. Chromosomes, found in the cell nucleus [nucleus: Controls what happens inside the cell. Chromosomes are structures found in the nucleus of most cells. ] , contain many genes.