The observable characteristics of an individual resulting from the interaction of its genotype with the environment.
Here's why this is the best definition:
* Observable Characteristics: Phenotype refers to the traits you can actually see or measure in an organism. This could include physical features like eye color, height, or fur color, as well as behavioral traits.
* Genotype: Phenotype is influenced by the genotype, which is the genetic makeup of an individual. The genes an organism inherits from its parents provide the blueprint for its traits.
* Environment: The environment plays a significant role in shaping phenotype. Factors like nutrition, temperature, or exposure to disease can all influence how genes are expressed.
Let's look at some examples:
* Height: A person's genotype might predispose them to be tall, but their environment (nutrition, overall health) will also influence their final height.
* Flower color: A flower's genotype determines the pigments it produces, but sunlight exposure can affect the intensity of the color.
Therefore, phenotype is not simply the expression of genes, but rather the result of a complex interplay between genetics and the environment.