Match the description with the term that it best describes.


1. These are disease-causing agents, such as germs. Bacteria, viruses, fungi, protozoa, and parasitic worms are all examples.


2. These are the largest organisms that can enter the body to cause infection. One example of these is flukes, which can infect the liver, intestines, and lungs and can be deadly in large numbers.


3. These are simple organisms that cannot make their own food. Examples of illnesses caused by these include yeast infections, thrush, athlete's foot, jock itch, and ringworm.


4. These are the smallest of the disease-causing agents that require living cells for survival and reproduction. Examples of illnesses that are caused by these include HIV/AIDS, mononucleosis, flu, cold, herpes, measles, mumps, chicken pox, smallpox, and polio.


6. These are one-celled microscopic organisms that cause infections. Examples of illnesses caused by these include meningitis, conjunctivitis (pink eye), pharyngitis (sore throat), bronchitis, pneumonia, and tuberculosis.


7. These are microscopic, single-celled organisms that are larger than bacteria and have a more complex cellular structure. They often feed on the nutrients of the body of their host. Examples of illnesses caused by these include malaria, African sleeping sickness, and amoebic dysentery.

a. pathogens

b. bacteria

c. viruses

d. fungi

e. protozoa

f. parasitic worms