Which term is used to describe an organism’s observable traits?

The correct term for describing an organism's observable traits is phenotype. Phenotype refers to the physical characteristics and traits that can be seen or measured, such as height, eye color, and leaf shape in plants. These traits are the result of the interaction between the organism's genotype—the genetic makeup—and environmental factors.

Understanding phenotype is crucial because it allows for the study of how different traits are expressed in organisms. For instance, two individuals may have the same genotype for a specific trait, but their phenotypes could differ due to environmental influences like nutrition or climate conditions.

This distinction between genotype and phenotype is fundamental in genetics, as it clarifies that while genotype pertains to the genetic information (the alleles) an organism carries, phenotype is what is actually expressed and observed.