21. Principles of Disease

Bacteria that convert nitrogen gas into ammonia are:

a. Nitrifying bacteria

b. Nitrogenous

c. Nitrogen fixers

d. Nitrification bacteria

The definitive host for Plasmodium vivax is

a. Human

b. Anopheles

c. A sporocyte

d. A gametocyte

Our microbiome is composed of a variety of microorganisms that live within and on our bodies. Research has shown our microbiota protects us against infectious pathogens, creates vitamins and minerals we need, and helps us digest our food. We act as a safe residence and food source for our microbiota. The relationship humans have with their microbiome could be described as?

a) A commensal relationship.

b) A resident relationship.

c) A mutual relationship.

d) A parasitic relationship.

Use the following choices to answer questions 2 and 3:

1. metacercaria

2. redia

3. adult

4. miracidium

5. cercaria

If a snail is the first intermediate host of a parasite with these stages, which stage would be found in the snail?

a. 1

b. 2

c. 3

d. 4

e. 5

First label the following diseases as bacterial, viral, or protozoan, and then indicate which ones are vectorborne infections: dengue fever, AIDS, chikungunya, Lyme disease, malaria.

What best describes the relationship between host and pathogen?

a. Mutualism

b. Parasitism

c. Commensalism

d. Endosymbiosis

Which of the following is an example of a commensal relationship?

In which type of symbiosis do both members benefit from their interaction?

a. Mutualism

b. Parasitism

c. Commensalism

d. Pathogenesis

List four types of symbiotic relationships, and give an example of each.