Which of the following correctly defines phenotype?

Phenotype refers to the observable traits or characteristics of an organism, which can include physical appearance, development, and behavior. This definition encompasses any measurable aspect of an organism that can be influenced by genetic factors. The phenotype results from the interaction between the organism's genotype, which is its underlying genetic composition, and environmental factors.

Understanding phenotype is crucial in fields like genetics and biology, as it helps scientists explore how traits are expressed and can be observed in living organisms. This concept is also essential for studies in areas such as natural selection, where observable traits can affect an organism's fitness and reproductive success in a given environment.

The distinction between phenotype and options like genetic composition or environmental influences is important; while those factors contribute to the phenotype, they do not define what phenotype itself is.