Final answer:
A live animal that transmits an infectious agent from one host to another is called a vector, such as a mosquito or tick. Vectors play a crucial role in the spread of diseases like malaria, Lyme disease, and the bubonic plague. They can transmit pathogens from one host to another through biting or physical contact.
Step-by-step explanation:
A live animal that transmits an infectious agent from one host to another is called a vector. A vector is typically an arthropod, such as a mosquito or tick, that transmits diseases like malaria or Lyme disease. It can also include other animals that spread zoonotic diseases, such as bats or rodents.
For example, the yellow fever virus is transmitted by mosquitoes, which act as vectors. When a mosquito bites an infected individual, it can become infected with the virus and then transmit it to another person through subsequent bites.
Other examples of vectors include ticks that transmit Lyme disease, fleas that spread the bubonic plague, and flies that transmit sleeping sickness.