What is the part of the cell that contains all the genetic information?

In a eukaryotic cell most of the genetic information is in the DNA of the chromosomes in the nucleus.

There is some DNA in mitochondria and chloroplasts, and this DNA also contains genes. For example, one version of a human mitochondrial gene can cause blindness.

In a prokaryotic cell, most of the genetic information is in the single chromosome, which is a naked circular DNA molecule in the cytoplasm. There are also some genes in small rings of DNA called plasmids. Some recombinant DNA techniques (genetic engineering) make use of plasmids for inserting genes into bacteria.