Which of the following is associated with multiple phenotypes?

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.

Which one of the following is an example of pleiotropy?

Write a short note on pleiotropy.

The phenomenon of pleiotropism refers to

$A$ gene which controls more than one character is called $:-$