Which structure encodes the traits in an organism?

The structure that encodes the traits in an organism is the gene. Genes are specific segments of DNA that contain the instructions for producing proteins, which ultimately determine the phenotype, or observable characteristics, of an organism. Each gene carries the information for a particular trait, such as eye color or height.

While chromosomes are the larger structures that organize and package genes within the cell, they themselves do not encode traits; rather, they serve as carriers of genes. RNA plays a crucial role in the process of translating the genetic information encoded in DNA into proteins, but it is not responsible for encoding the traits itself. Enzymes, which are proteins produced by gene expression, facilitate biochemical reactions within the body, but they do not carry or encode information about traits.

Therefore, the gene is the fundamental unit that directly encodes the hereditary information passed from parents to offspring, leading to the expression of specific traits.