What components of a cell are responsible for determining the characteristics of a living organism?

Genes are the fundamental components of a cell that determine the characteristics of a living organism. They are segments of DNA that contain the instructions necessary for producing proteins, which in turn play critical roles in various biological processes. The sequence of nucleotides in genes encodes for specific traits, such as eye color, height, and susceptibility to certain diseases, thereby influencing the overall phenotype of the organism.

While proteins are essential for carrying out many functions in the body, they are produced based on the information provided by genes. Ribosomes serve as the site of protein synthesis, translating the genetic code from mRNA into polypeptide chains, but they do not determine the characteristics themselves. Membranes form the structural boundary of cells and regulate the movement of substances in and out, but like ribosomes, they do not play a direct role in defining the genetic characteristics of an organism. Instead, they support cellular function and maintenance. Therefore, genes are the critical components that directly establish and influence the traits of living organisms.