Answer:
Pleiotropy.
Step-by-step explanation:
Pleiotropy may be defined as when the single gene shows the multiple phenotypic traits. The gene is known as the pleiotropic gene and its mutation may affect the several phenotype expression.
The frizzle gene control the multiple phenotype effects like defective feathers, high blood flow, low egg lay rates and high metabolic rates. This is a case of pleiotropy because here a single gene is responsible for the multiple phenotypes.
Thus, the answer is pleiotropy.