Answer:
Natural killer cells are lymphocytes that function as part of the innate immune system.
Natural killer cells destroy virus infected cells.
Step-by-step explanation:
Natural killer cells is a type of white blood cells which is responsible for the protection of body against pathogens such as viruses and bacteria etc. Natural killer cells is a type of innate immune system which takes action immediately against viruses. Natural killer cells is not adaptive immune system, it is already present in the body of organisms. It is also considered as the first line of defense of the body against harmful microbes.