Which of the following best explains the term 'phenotype'?

The term 'phenotype' refers to the observable physical characteristics or traits of an organism, which result from the interaction of its genetic makeup (genotype) with the environment. This includes traits such as height, eye color, and blood type. The phenotype is what is physically expressed, and it can vary based on both genetic factors and environmental conditions, making it a crucial concept in genetics and heredity.

The other options focus on different aspects of genetics. The first option refers to the genotype, which is the underlying genetic code rather than the physical expression of that code. The third option mentions environmental influences, which do play a role in shaping the phenotype but do not define the term itself. The fourth option discusses chromosomal count, which is a genetic characteristic but does not encompass the concept of phenotype. Thus, the choice that accurately reflects the meaning of phenotype is the one that emphasizes the physical manifestation of traits.