A culture medium consisting of agar, peptone, and beef heart is a

The source of nutrients in nutrient agar is

Which of the following is an example of a metabolic activity that could be used to measure microbial growth?

Which group of microorganisms is most likely to spoil a freshwater trout preserved with salt?

Which of the following is NOT a direct method to measure microbial growth?

Which of the following is the best definition of generation time?

During which growth phase will gram-positive bacteria be most susceptible to penicillin?

Consider a culture medium on which only gram-positive organisms such as Staphylococcus aureus colonies can grow due to an elevated NaCl level. A yellow halo surrounds the growth, indicating the bacterium fermented a sugar in the medium, decreasing the pH as a result and changing the color of a pH indicator chemical. This type of medium would be referred to as a(n)

Most bacteria reproduce by

Which of the following is an advantage of the direct microscopic count?

Patients with indwelling catheters (long-term tubes inserted into body orifices for drainage, such as through the urethra and into the urinary bladder) are susceptible to infections because

The term aerotolerant anaerobe refers to an organism that

Which of the following elements is NOT correctly matched with its cellular function?

Pathogenic bacteria isolated from the respiratory or intestinal tracts of humans are

Which of the following is an advantage of the standard plate count?

Salts and sugars work to preserve foods by creating a

The addition of which of the following to a culture medium will neutralize acids?

The biosafety level (BSL) for a clinical microbiology laboratory working with potentially airborne pathogens, such as tuberculosis bacteria, is

The biosafety level (BSL) for most introductory microbiology laboratories is

Which of the following pairs of microbe classification terms and optimal growth temperatures is mismatched?

A sample of milk is tested for its bacterial content in a plate count assay. A one-milliliter sample of the milk is diluted in a 1:10 dilution series. One milliliter of the third dilution tube is plated in a pour plate. After incubation, the plate has 54 colonies, indicating that the original milk sample contained

Most fungi grow best at pH

Which of the following is an organic growth factor?

Most bacteria grow best at pH

Which enzyme catalyzes the reaction: H2O2 + 2H+ → 2H2O?

Which enzyme catalyzes the reaction: O2- + O2- + 2H+ → H2O2 + O2?

Which enzyme catalyzes the reaction: 2H2O2 → 2H2O + O2?

An experiment began with 4 cells and ended with 128 cells. How many generations did the cells go through?

In one hospital, Pseudomonas aeruginosa serotype 10 infected the biliary tract of 10 percent of 1300 patients who underwent gastrointestinal endoscopic procedures. After each use, endoscopes were washed with an automatic reprocessor that flushed detergent and glutaraldehyde through the endoscopes, followed by a tap water rinse. P. aeruginosa serotype 10 was not isolated from the detergent, glutaraldehyde, or tap water. What was the source of the infections?

Thirty-six colonies grew in nutrient agar from 1.0 ml of undiluted sample in a standard plate count. How many cells were in the original sample?

If cells are grown in media containing amino acids labeled with radioactive nitrogen (15N), most of the radioactivity will be found in the cells'

Three cells with generation times of 60 minutes are inoculated into a culture medium. How many cells are there after 5 hours?

Assume you inoculated 100 cells, with a generation time of 20 minutes, into 100 ml of nutrient broth. You then inoculated 100 cells of the same species into 200 ml of nutrient broth. After incubation for 4 hours, you can reasonably expect to have