EXERCISES, LESSON 3
INSTRUCTIONS. The following exercises are to be answered by marking the lettered
response that best answers the question or by completing the incomplete statement or
by writing the answer in the space provided at the end of the question.
After you have completed all the exercises, turn to "Solutions to Exercises" at
the end of the lesson and check your answers.
Crustaceans are important in the sanitation of natural bodies of water in that they
help to control ___________________________.
The presence of rotifers in water is an indication of _________ pollution levels.
Bacteria of the genera Escherichia and Enterobacter are known as _________
The activated sludge process in sewage treatment is based upon __________
In anaerobic sewage digestion, _____________________ forming bacteria
predominate in the first stage, and __________________forming bacteria
become active in the second stage.
The septic tank is an example of _____________________ digestion.
The destruction of all microorganisms is known as ____________________.
The destruction of all pathogenic organisms id known as __________________.
Microorganisms may be destroyed by either _______________________ or