AP-Micro Microbiology: Laboratory Operations and Safety 2

Question 1

Which biosafety cabinet (BSC) class provides personnel protection only and does NOT protect the product from contamination?

Accepted Answer

Class I

Answer

Class I BSCs exhaust air through a HEPA filter to protect personnel and the environment but draw unfiltered room air over the work surface, offering no product protection.

Question 2

A technician must dispose of a culture plate containing a BSL-2 organism. What is the correct first step before placing it in the biohazard waste bag?

Accepted Answer

Autoclave the plate at 121°C for at least 15 minutes

Answer

BSL-2 biological waste must be autoclaved (decontaminated) before disposal to render the organisms non-viable.

Question 3

When calibrating a micropipette, which technique produces the most accurate volume delivery for aqueous solutions?

Accepted Answer

Air displacement with a pre-wet tip

Answer

Pre-wetting the tip with the solution before aspirating the target volume reduces error caused by vapor pressure and minimizes loss on tip walls, improving accuracy for aqueous samples.

Question 4

The use of personal protective equipment (PPE) is governed by the hierarchy of controls. Where does PPE fall in this hierarchy?

Accepted Answer

Last line of defense

Answer

PPE is the last line of defense in the hierarchy of controls, used when elimination, substitution, engineering, and administrative controls cannot adequately reduce risk.

Question 5

A researcher accidentally spills a small volume of a BSL-2 culture on the bench. What is the correct immediate action?

Accepted Answer

Cover with paper towels soaked in 10% bleach for 20 minutes, then clean up

Answer

A 10% bleach (hypochlorite) solution applied for at least 20 minutes effectively disinfects BSL-2 spills before physical clean-up.

AP Practice Test

AP Practice Test

AP-Micro Microbiology: Laboratory Operations and Safety 2