What is the term for the determination of traits by a combination of both genetic and environmental factors, in which a genotype provides a range within which a phenotype may be expressed?

Multi-factorial transmission.

Explanation:

The genotype may be defined as the genetic constitution of the individual and phenotype is the physical appearance of the individual. The phenotype of the individual is affected both by the genetic factors and the environmental factors.

Multi factorial transmission may be defined as the different factors are involved in the transmission of the particular trait. The environment and genetic factors shows equal contribution for the expression of the trait. The different multiple factorial trait are neural tube defects and height.

Thus, the answer is multi factorial transmission.

multifactorial transmission

Explanation:

It is mostly assumed that one genetic trait is regulated by one gene. However, some genetic traits are controlled by more than one gene. Also, some of these genetic traits are influenced by both genes and abiotic factors such as temperature conditions, diet, lifestyle, etc. These genetic traits are said to be following the multifactorial transmission as they are regulated by more than one controlling factor.

For example, skin color in human beings is regulated by more than one gene. Exposure to light and pollution also affects the skin tone of a person. Being a multifactorial trait, skin color in human beings does not exhibit distinct categories. Rather it exhibits continuous variation and the phenotype ranges from light to very dark with many intermediate categories in between.