disease types:Parasitical Diseases-These diseases are caused by parasites. Parasites attack us by entering red blood cells in our body destroying them one by one.
Bacterial Diseases-These diseases are caused by bacteria. Bacteria live everywhere around us but less than 1% is bad for us.
Fungal Diseases-These diseases are caused by fungi. Examples of fungi are mushrooms, mold, yeast, and penicillin.
why does a virus need a host cell? virus is just a brain without a body. They need to take over a host's body, and use it to produce more virus brains. They can't do it themselves as they don't have the necessary reproduction machinery.
epidemics & pandemics: An epidemic occurs when an infectious disease spreads rapidly to many people. A pandemic is a global disease outbreak.