EXERCISES, LESSON 1
INSTRUCTIONS: Answer the following exercises by marking the lettered response that
best answers the question, by completing the incomplete statement, or by writing the
answer in the space provided at the end of the exercise.
After you have completed all of these exercises, turn to "Solutions to Exercises" at the
end of the lesson, and check your answers. For each exercise answered incorrectly,
reread the material referenced with the solution.
A microorganism is defined as
2. Which of the following statements best describes the effect of microorganisms on
a. Microorganisms generally do not affect people. They never perform beneficial
or helpful activities, and only a few cause disease.
Most microorganisms cause disease in man; only a few are beneficial.
c. Most microorganisms are not harmful; some even provide benefits.
A few may cause disease.
Exercises 3-5 below are descriptions of microorganisms. Write the name of the correct
microorganism in the blank after each description.
3. These are very small, one-celled plants. Typically it would take 25,000 individuals
placed side by side to equal one inch. They are the most common cause of foodborne
4. These organisms obtain nourishment by living on or in another organism. Some
are one-celled; others are multi-celled and can be seen without a microscope. They
present a problem in those countries that use human fecal matter as a fertilizer.
5. These are the smallest and simplest type of microorganism and can be seen only
through an electron microscope. They must change the structure of a living cell in order
to reproduce. _____________________