NEETZoologyPrinciples of Inheritance and Variation
What is the term for a gene that exhibits multiple phenotypic expressions?
Options
- APolygenic gene
- BPleiotropic gene
- CMonogenic gene
- DEnvironmental gene
Correct answer
B. Pleiotropic gene
Step-by-step solution
We have so far seen the effect of a gene on a single phenotype or trait. There are however instances where a single gene can exhibit multiple phenotypic expressions. Such a gene is called a pleiotropic gene. The underlying mechanism of pleiotropy in most cases is the effect of a gene on metabolic pathways which contribute towards different phenotypes. An example of this is the disease phenylketonuria, which occurs in humans. The disease is caused by mutation in the gene that codes for the enzyme phenylalanine hydro