What structure contains the genetic information for an organism?

The structure that contains the genetic information for an organism is DNA. DNA, or deoxyribonucleic acid, serves as the molecular blueprint for all living organisms. It is composed of sequences of nucleotides that encode the information necessary for the development, functioning, growth, and reproduction of organisms.

While chromosomes are made up of DNA and serve as the physical structures that house it within the nucleus of eukaryotic cells, it is the DNA itself that carries the genetic code. Each chromosome comprises a long strand of DNA that is tightly coiled and packaged. Thus, while it's correct that chromosomes contain genetic information, they are not the fundamental unit that contains the genetic instructions.

RNA, or ribonucleic acid, plays a role in the expression of genetic information, particularly in protein synthesis, but it does not store genetic information in the same way that DNA does. Protein, on the other hand, is synthesized based on the information carried by the DNA but does not contain the genetic information itself.

Overall, DNA is the primary and most crucial molecule that contains and transmits the genetic information essential for life.