Final answer:
A living organism that carries microorganisms from an infected person to another person is called a vector, which can be an insect like a mosquito or a tick. These organisms spread diseases by transferring pathogens from one host to another.
Step-by-step explanation:
A living organism that carries microorganisms from an infected person to another person is called a vector. These are organisms that transmit pathogens from one host to another. Insects like mosquitoes and ticks are the most common vectors, and they can spread a variety of diseases, including Lyme disease and West Nile virus. Vectors can be either mechanical or biological—the former carry the pathogen on their bodies while the latter are infected by the pathogen and can transmit it through a bite or other means of transfer. To prevent vector-borne diseases, it is recommended to avoid contact with vectors by wearing protective clothing and using insect repellent.