Final answer:
Tuberculosis is a deadly infectious disease caused by Mycobacterium tuberculosis. It primarily affects the lungs and is estimated to infect one-third of the world's population.
Step-by-step explanation:
Tuberculosis (TB) is a deadly infectious disease caused by the bacterium Mycobacterium tuberculosis. It primarily affects the lungs, but can also affect other parts of the body. It is estimated that approximately one-third of the world's population is infected with TB, with 9.6 million new cases and 1.5 million deaths worldwide in 2014.