Answer:
-A single gene can influence multiple traits.
-A single trait can be controlled by multiple genes.
Explanation:
1. A single gene influences two or more phenotypic traits known as a pleiotropic gene. Pleiotropy is common in the genetics of complex disease.
Example: Phenylketonuria
It is an inherited disorder in which the level of phenylalanine is increased in the human body. This is happening because of the defect in a single gene on chromosome 12 that codes for phenylalanine hydroxylase (enzyme). This enzyme affects multiple system e.g., nervous and integumentary systems.
2. A polygenic trait is one whose phenotype is influenced by more than one gene. Polygenic traits are also controlled by environmental factors.
Example: Height, Skin color
These traits show continuous distribution because they are also controlled by many different genes. Epigenetics and environmental factors are also involves.
Mandalian (inherited) traits are controlled by different genes.
