Exam 11: Microbial Growth and Control

Which of the following cell types cannot protect itself from lysis when placed in a hypotonic environment?

MacConkey agar is selective in that it inhibits Gram-positive bacterial growth and differential in that it distinguishes ________ from other coliforms that are unable to ferment lactose.

The procedure illustrated below is ________.

The key characteristic of log phase is ________.

Which of the following methods of measuring cell density cannot distinguish between living and dead bacterial cells and thus may not provide the data needed in an actual infection or contamination? (Select all that apply)

An enriched medium ________.

________ concentrates low numbers of bacteria before plating.

________ is used to slow or stop microbial metabolism and growth but does not kill microbes.

Members of the microbial communities that form bacterial biofilms show ________ because of their ability to both cause diseases and their enhanced resistance to relatively high concentrations of antibacterial agents.

A mesophile has an optimum growth rate ________.

A 60-80% solution of alcohol ________.

Spectrophotometry ________.

What does a bacterium have to do before cell division can take place? (Select all that apply)

A(n) ________ uses fermentation pathways only but is not harmed by presence of oxygen.

Microbial cell density may be determined using ________. (Select all that apply)

Which of the following microorganism types has an optimum growth pH of 5 to 6?

This specimen is placed in sample bottles that are cultured aerobically and anaerobically.

The cell density of an exponentially growing culture of E. coli as a function of time is shown below. The slope of the line marked x is ________.

The key characteristic of lag phase is ________.

The bracket marked "w" is the range of temperature where ________ bacteria have their optimum growth temperature.