Which of the following best describes the role of essential genes?

Essential genes are those that are critical for the survival of an organism. These genes perform vital functions that maintain basic cellular processes and overall organism integrity. If an essential gene is mutated or deleted, the organism may not be able to survive, reflecting the gene's importance in fundamental biological functions such as metabolism, DNA replication, and cellular repair.

In contrast, the other options refer to different concepts. While specific genes may indeed relate to growth and reproduction, the term "essential" more directly correlates with survival. Information about ancestry pertains to phylogenetic analysis, not essentiality, and genes that result in physical traits relate to phenotypic expression rather than their essentiality for survival. Thus, the defining characteristic of essential genes is their necessity for an organism's survival, distinguishing them from other types of genes that might influence traits or evolutionary history.