What term describes the observable traits expressed by an organism?

The term that describes the observable traits expressed by an organism is phenotype. Phenotype encompasses all the physical expressions of an organism's genetic information, including traits such as height, eye color, and flower color in plants. This expression results from the interaction between the organism's genotype, which is its genetic makeup, and environmental factors.

Understanding phenotype is crucial because it illustrates how genetic information can manifest in real-world characteristics. For instance, two plants may have the same genotype for flower color, but if one is grown in different soil conditions, the flower color may appear different, showcasing the importance of environmental influence on phenotype.

In contrast, genotype refers to the specific genetic constitution, alleles are the alternative forms of a gene found at a specific location on a chromosome, and chromosomes are the structures that organize DNA within the cell. While these terms are related to the study of genetics, they do not directly describe the observable traits of an organism.