Final answer:
Mononucleosis and HIV are two diseases that can destroy the immune system.
Step-by-step explanation:
Two diseases that can destroy the immune system are Mononucleosis and HIV.
Mononucleosis, also known as 'mono', is a viral infection caused by the Epstein-Barr virus (EBV). It can weaken the immune system, making individuals more susceptible to other infections.
HIV, or Human Immunodeficiency Virus, attacks and destroys the immune system cells, specifically CD4 cells, which play a key role in fighting off infections and diseases.
Learn more about Effects of diseases on the immune system