What is the significance of DNA in living organisms?

The significance of DNA in living organisms is profound, as it fundamentally serves as the blueprint for all living entities. DNA, or deoxyribonucleic acid, contains the genetic instructions necessary for the growth, development, functioning, and reproduction of organisms. This genetic material dictates everything from physical traits to biochemical processes, guiding the synthesis of proteins that perform most of the functions in a cell. The specific sequence of nucleotides in DNA encodes the information required to build and maintain an organism, making it essential for life itself.

While other choices address various biological processes, they do not capture the essence of DNA's role. For instance, while digestion and nutrient absorption are crucial for survival, they are more associated with the functions of organs and systems rather than the genetic blueprint. Similarly, energy production is a critical cellular function primarily attributed to cellular metabolism, not directly to DNA. Lastly, though some viruses do contain DNA as their genetic material, this does not encompass the primary role DNA plays in the cellular biology of living organisms as a whole, which is to carry and transmit genetic information across generations. Thus, the role of DNA as the carrier of genetic instructions for life is its most significant aspect.