Question

what are vectors how do they cause the spread of disease

Answer 1

Vector is an animal that transmits pathogens from one host to another. For example, female Anopleles mosquito transmits malarial parasite from one person to other and spreads malaria.

Answer 2

the organism that spread the diseases are called vectors.
e. g mosquito
dog etc

they carry the causative agents and transfer them from infected to healthy person

like mosquito female anopheles carry plasmodium that cause malaria