What term best describes the complete set of genes in an organism?

The term that best describes the complete set of genes in an organism is "genome." The genome encompasses all the genetic material found within an organism, including not only the genes that encode proteins but also non-coding regions of DNA that may have regulatory or structural functions. Each species has a unique genome that carries the hereditary information vital for growth, development, and functioning.

To further clarify, the proteome refers to the complete set of proteins that can be expressed by the genome, reflecting the functional aspect of gene expression, rather than the genes themselves. A chromosome is a structure composed of DNA and proteins that contains part of the genome; thus, it represents a portion rather than the entirety. The phenotype is the observable physical or biochemical characteristics of an organism, which result from the interaction of its genotype (the genetic constitution) with the environment. Overall, the genome is the most accurate term that encapsulates the full collection of genetic information in an organism.