What does an organism's phenotype describe?

• A. The environmental conditions affecting an organism
• B. The observable physical and physiological traits of an organism
• C. The evolutionary history of an organism
• D. The genetic makeup of an organism

Answer: (B)

Verified step by step guidance

1. Understand that the term 'phenotype' refers to the observable characteristics of an organism.
2. Recognize that these characteristics include both physical traits, such as height and color, and physiological traits, such as metabolic rate.
3. Differentiate phenotype from 'genotype,' which refers to the genetic makeup of an organism that contributes to its phenotype.
4. Consider how environmental factors can influence the phenotype, even though they are not part of the phenotype itself.
5. Conclude that an organism's phenotype is the result of the interaction between its genotype and the environment, leading to the observable traits.