Final answer:
The immune system fights off diseases by generating an army of cells to kill specific pathogens. It consists of the innate immune response and the adaptive immune response.
Step-by-step explanation:
The immune system fights off diseases. The system contains cells that can attack and destroy pathogens, and when you are sick, these cells temporarily increase. Through the help of your immune system, your body can generate an army of cells to kill that one specific pathogen. The immune system can be divided into two overlapping mechanisms to destroy pathogens: the innate immune response, which is relatively rapid but nonspecific, and the adaptive immune response, which is slower but highly specific and effective at attacking a wide variety of pathogens.