Some Disorders That Can Result
Bacteria are microscopic, single-celled organisms without a nucleus.
Viruses are small infectious organisms—much smaller than a fungus or bacterium. They cannot reproduce on their own. They must invade a living cell and use that cell’s machinery to reproduce.
Chickenpox Chickenpox Chickenpox is a highly contagious viral infection with the varicella-zoster virus that causes a characteristic itchy rash, consisting of small, raised, blistered, or crusted spots. Chickenpox... read more and shingles Shingles Shingles is a painful skin rash caused by a viral infection that results from reactivation of the varicella-zoster virus, the virus that causes chickenpox. What causes the virus to reactive... read more
Fungi are neither plants nor animals. Their size ranges from microscopic to easily seen with the naked eye. They include yeasts, molds, and mushrooms.
Parasites are organisms that survive by living inside another usually much larger organism (the host). They include worms and single-celled organisms called protozoa (which, unlike bacteria, have a nucleus).
Plasmodium falciparum (a species of protozoa)