What are genes primarily made of?

Genes are primarily made of deoxyribonucleic acid (DNA), which is a molecule that encodes the genetic instructions for the development, functioning, growth, and reproduction of all known organisms and many viruses. DNA consists of two long strands forming a double helix, which is composed of nucleotides. Each nucleotide contains a phosphate group, a sugar, and a nitrogenous base. The specific sequence of these nitrogenous bases (adenine, thymine, cytosine, and guanine) determines the genetic information carried by the gene.

While proteins, carbohydrates, and ribonucleic acid (RNA) are important biological macromolecules, they are not what genes are fundamentally composed of. Proteins are synthesized according to the instructions provided by genes, functioning as the building blocks of cells, while carbohydrates serve primarily as energy sources and structural components. RNA plays a critical role in translating the genetic information from DNA into protein but does not form the genes themselves. Thus, understanding that genes consist of DNA is crucial for grasping the principles of genetic inheritance and molecular biology.