Question

A reaction norm is:

1) The average time it takes to respond to a stimulus
2) A graph of the phenotypic possibilities of a single genotype across a range of environments
3) The range of genotypic expression in a single environment
4) The opposite of phenotypic plasticity

Answer 1

A reaction norm is 2) a graph of the phenotypic possibilities of a single genotype across a range of environments.

Step-by-step explanation:

The correct answer is option 2) A graph of the phenotypic possibilities of a single genotype across a range of environments.

A reaction norm is a graphical representation of how a single genotype can result in different phenotypic expressions in different environmental conditions. It shows the range of possible phenotypes that can be observed for a particular genotype across varying environmental factors. For example, a reaction norm graph can illustrate how a plant genotype may have different growth rates or flower colours depending on factors such as temperature, sunlight, or soil nutrient availability.