Final answer:
A living organism that transfers pathogens from one host to another is called a vector, commonly exemplified by arthropods such as ticks and mosquitoes.
Step-by-step explanation:
A living organism that carries microorganisms from an infected person to another person is known as a vector. In the context of disease transmission, vectors are animals, often arthropods like ticks and mosquitoes, that transport pathogens from one host to another. These vectors can transfer illnesses such as Lyme disease, West Nile virus, Dengue Fever, and Yellow Fever. While some vectors become infected with the pathogen they carry and transmit it biologically, others may transfer pathogens on their bodies without becoming infected, which is known as mechanical transmission. An important measure to prevent diseases spread by vectors is to avoid contact with them, for instance, by wearing protective clothing and using insect repellent.