Which molecule carries the genetic instructions used in the growth and functioning of all living organisms?

The molecule that carries the genetic instructions for the growth and functioning of all living organisms is DNA. DNA, or deoxyribonucleic acid, is a double-helix structure composed of nucleotide subunits, which contain a sugar, a phosphate group, and a nitrogenous base. The specific sequence of these nitrogenous bases encodes genetic information that guides cellular processes, including development, reproduction, and maintenance of organisms.

In contrast, while RNA (ribonucleic acid) plays a crucial role in translating the genetic code from DNA into proteins, it does not store genetic information. Proteins are the result of gene expression and perform a wide range of functions in the cell, but they do not carry genetic instructions themselves. Lipids, such as fats and oils, have essential roles in cell structure and energy storage but are not involved in the genetic coding process. Hence, DNA is fundamentally recognized as the molecule responsible for carrying and transmitting genetic information across generations.