QUESTION 1

Define the concept of universal precautions.

Universal precautions means any and all samples, whether known or unknown, are to be treated as

potentially hazardous (or pathogenic) materials.

QUESTION 2

List at least 3 observations a researcher would be sure to note while assessing an unknown microbial

sample.

A lab researcher would be certain to note: Size and shape; Any observable motility; Gram status (positive

or negative); The presence of any chemical reactions; Changes in color localized to the organism or the

surrounding media; Capture (or draw) images of any of the characteristics described above

QUESTION 3

While observing an unknown sample of limited amounts, a researcher must determine the following

observations: (1) the presence of any motility and (2) its Gram status using the same sample—the liquid

sample cannot be divided. Which would you determine first and why?

You must determine motility before determining the Gram status. Motility requires a wet mount, while

Gram staining requires heat fixing the sample. If one were to begin with the Gram stain the heat fixation

process would kill the organism, making any observations regarding motility impossible. The correct

approach would be to place the liquid culture on a glass slide and determine its motility status. Next, the

same liquid culture can be heat fixed and Gram stained.

QUESTION 4

A facultative anaerobe is a microorganism capable of growth under what conditions?

A facultative anaerobe is capable of growth under aerobic (with oxygen) and anaerobic (without oxygen)

conditions.