You Need to Determine If a Pure Culture of Bacteria

question 29

Multiple Choice

You need to determine if a pure culture of bacteria is gram-positive or gram-negative, but you've just spilled your only solution of crystal violet so you can't do a Gram stain. You decide to try a lysozyme treatment on a sample of each culture and then examine the samples under the microscope. The expected result is _______.

• A) gram-negatives will lyse and appears as debris; gram-positives will be unaffected
• B) gram-positives will lyse and appears as debris; gram-negatives will lose cellular morphology and appear as cocci
• C) gram-positives will lyse and appears as debris; gram-negatives will lyse but more slowly
• D) gram-positives will lyse and appears as debris; gram-negatives will be unaffected
• E) gram-negatives will lyse and appears as debris; gram-positives will lose cellular morphology and appear as cocci

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Definitions:

Enantiomers

Molecules that are mirror images of each other and are non-superimposable.

Asymmetric Carbon Atoms

Atoms of carbon in a molecule that are bonded to four different groups, leading to chirality or optical activity.

Meso Compound

A type of stereoisomer with multiple chiral centers that is superimposable on its mirror image, making it achiral.

Chi-Squared Test

A statistical test used to determine the significance of the observed differences between categorical datasets and expected outcomes.