What molecule carries the genetic information in living organisms?

The molecule that carries genetic information in living organisms is DNA (deoxyribonucleic acid). DNA is composed of two long strands that coil around each other to form a structure known as a double helix. Each strand is made up of sequences of nucleotides, which contain the genetic instructions used in the development, functioning, growth, and reproduction of all known living organisms and many viruses.

DNA serves as the blueprint for life, as it holds the information necessary for constructing proteins through the processes of transcription and translation. The sequences of the nucleotides represent specific genes, which are the units of heredity. In contrast, while RNA (ribonucleic acid) plays crucial roles in translating that genetic information into proteins, it is not the primary carrier of genetic information. Proteins, despite being essential for various cellular functions, do not carry genetic information; they are synthesized based on the instructions provided by DNA. Sugars do not play a role in encoding genetic information either; they serve other functions within biological systems, such as providing energy.

Thus, the role of DNA as the molecule that carries and preserves genetic information makes it a fundamental element of life itself.