Which molecule is responsible for carrying genetic information within a cell?

The molecule responsible for carrying genetic information within a cell is DNA. Deoxyribonucleic acid (DNA) serves as the hereditary material in nearly all living organisms. It contains the instructions needed for an organism's growth, development, functioning, and reproduction. The structure of DNA, which is a double helix composed of nucleotides, allows it to store and transfer genetic information accurately during cell division and protein synthesis.

RNA, while important in the transmission of genetic information and involved in protein synthesis, primarily acts as a messenger carrying instructions from DNA to the rest of the cell. Proteins are the products of gene expression but do not carry genetic information themselves; rather, they perform various functions within the cell based on the instructions encoded in DNA. Enzymes, a subset of proteins, facilitate biochemical reactions but do not carry genetic information either. Therefore, DNA is the molecule that definitively fulfills the role of carrying genetic information.