Nucleic Acids - In order to duplicate themselves (replicate), cells have to carry the information describing how to do so.

The nucleic acids, DNA (deoxyribonucleic acid) and RNA (ribonucleic acid), are the only known molecules in the cell that carry such information.

All of a cell's information is contained within the DNA.

DNA is, of course, a component of chromosomes.

There are three primary types of RNA - messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA).

RNAs are made by copying a portion of the DNA and are largely involved in making proteins, though in eukaryotes, another minor type of RNA, called small nuclear RNA (snRNA) is involved in processing of the other three types of RNA (see here).