Question

the way in which genotype and environment interact to produce a phenotype is measured by the
○ overall size of the organism.
○ phenotypic index.
○ norm of reaction.
○ principle of independent assortment.

Explanation:

1. Analyze each option:

• "overall size of the organism" refers to the physical dimension of an organism, not the interaction of genotype and environment to produce phenotype.
• "phenotypic index" is not a term used to describe the interaction of genotype and environment to produce phenotype.
• "norm of reaction" is defined as the set of phenotypic expressions of a single genotype across different environments, which measures how genotype and environment interact to produce a phenotype.
• "principle of independent assortment" is a Mendelian principle related to the segregation of alleles during gamete formation, not related to genotype - environment interaction for phenotype production.

Answer:

C. norm of reaction.