Name: ______Period: ______

Bacteria Study Questions

  1. All living organisms except for bacteria are eukaryotic. All bacteria are prokaryotic. What characteristics describe prokaryotic organisms?
  1. List three unusual environments where Archaea (extremophiles) can be found.
  1. If you discover a new bacterium that makes food energy from sunlight and is an important food source for small snails, what main type of Eubacteria would it be classified into?
  1. Define the term “chemoautotrophic”.
  1. Eukaryotic DNA (like in humans) are all double helix strands with a matching homologous strands found in the nucleus of cells of the organism. In what ways is bacterial DNA different? How is it similar?
  1. Some bacteria, especially spirilla, can move very well. What structure is used for movement?
  1. Bacteria are classified by their Gram stain reaction, then by arrangement, then shape and growth pattern (example: Gram negative diplobacillus). What would be the full classification for a bacterium that contributes to tooth decay, which you can observe through a microscope to be a purple-stained cluster of round bacteria?
  1. Draw a streptobacillus bacteria sample.
  1. List the four characteristics used by microbiologist to classify bacteria (your book is useful for this, but they are mentioned on this page and on the notesheet.)
  1. People are very concerned about bacteria being on countertops and other such surfaces. How would you explain to someone why it is not likely to find a large amount of bacteria in such a location?
  1. Even though there are some places that bacteria do not grow well, they have a way of surviving these conditions. What is this survival mechanism called?
  1. Name and describe the process by which bacteria reproduce.
  1. What do you think is the greatest benefit that bacteria provide and why? (There are several possible correct answers depending on how you explain it.)
  1. A scientist, Alexander Fleming, was growing bacteria and got his cultures contaminated by a mold called Penicillium notatum. The mold released a chemical that killed his bacteria. Voila! Penicillin was discovered. Another scientist was growing a soil bacterium called Bacillus subtilus, which killed other bacteria in the culture just like penicillin did. What antibiotic do you think was discovered by studying Bacillus subtilus? (hint: it’s an ointment probably in your medicine cabinet at home, ask your Mom)
  1. The active ingredient in acne medicines is benzoyl peroxide. Peroxides are chemicals that vigorously create and give off oxygen. Do you think that the bacterium that causes acne (Propionibacterium acnes) is an anaerobic or aerobic bacterium? Explain.