The phenomenon of a single gene regulating several phenotypes is called

Which of the following is not an example of pleiotropy?

What is a single gene that can control more than one trait called?

Observe the phenotypic effects of a gene with $2$ alleles $B$ and $b$ in pea plant.

Genotype	Starch grain size and Seed shape
$BB$	Large,Round
$Bb$	Intermediate,Round
$bb$	Small,Wrinkled

Which of the following is incorrect in concern to above facts $:-$

Find the correct statement.
$(1)$ Generally a gene regulates a trait,but sometimes one gene has an effect on multiple traits.
$(2)$ The trait $AB$-blood group of man is regulated by one dominant allele and another recessive allele. Hence it is co-dominant.

In which type of disorder does a single gene mutation show multiple phenotypic expressions?