Chapter 06 Bacterial Growth, Nutrition

Which of the following terms best describes bacteria that rely on other organisms to make their organic compounds?

• lithotroph

• phototroph

• heterotroph

• autotroph

• organotroph

Which of the following answers best describes selective media?

• Favors the growth of one organism over another.

• Exposes biochemical differences between species that grow equally well on the medium.

• Contains specific ingredients at known concentrations.

• Contains ingredients (such as yeast extract or blood) that are poorly defined.

Which of the following is a characteristic of bacteria that grow in a biofilm?

• Only Gram-positive bacteria produce biofilms.

• Bacteria in biofilms are resistant to destruction.

• Individual cells in the biofilm are actively motile

• Biofilms contain only a single type of bacterium.

Which category would apply to bacteria that are aerobic but cannot survive unless the concentration of oxygen is reduced below normal atmospheric levels?

• Strict aerobe

• Microaerophile

• Facultative anaerobe

• Strict anaerobe

A thermophilic bacterium is one that grows in an environment where

• the concentration of salt is 20%–30%.

• the pH is above 8.

• the temperature is 50ºC–70ºC.

• oxygen is always present in the atmosphere.