Question

1. an inoculated thioglycolate medium culture tube shows dense growth at the surface and turbidity throughout the rest of the tube. what is your conclusion? a. the organisms die in the presence of oxygen b. the organisms are facultative anaerobes. c. the organisms should be grown in an anaerobic chamber. d. the organisms are obligate aerobes. 4. bacteria that grow in mine drainage at ph 1 - 2 are probably which of the following? a. alkaliphiles b. acidophiles c. neutrophiles d. obligate anaerobes 5. pseudomonas aeruginosa is a common pathogen that infects the airways of patients with cystic fibrosis. it does not grow in the absence of oxygen. the bacterium is probably which of the following? a. an aerotolerant anaerobe b. an obligate aerobe c. an obligate anaerobe d. a facultative anaerobe

Explanation:

For question 3, facultative anaerobes can grow with or without oxygen. Dense growth at the surface (where oxygen is present) and turbidity throughout (showing growth in other oxygen - availability conditions) indicates facultative anaerobes. For question 4, bacteria growing in a very low pH (1 - 2) are acidophiles as they thrive in acidic environments. For question 5, an organism that does not grow in the absence of oxygen is an obligate aerobe.

Answer:

1. B. The organisms are facultative anaerobes.
2. B. acidophiles
3. B. an obligate aerobe