Answer:
Vector
Explanation:
Diseases can be transmitted by the mechanical or the biological vector. Vector is an animal (typically can be called as an arthropod) which carries disease from one host to another.
Mechanical transmission is the one in which an animal which carries the pathogen from on host body to the another without being infected by it. It is facilitated by the mechanical vector.
Biological transmission is th eone which occurs when pathogen reproduces within the biological vector which transmits pathogen from one host body to the another.
