A Microbiology Student in a Research Lab Repeated an Experiment

question 39

Multiple Choice

A microbiology student in a research lab repeated an experiment described by others using the identical bacterial isolate, the same growth medium, and the same growth conditions. However, the student was unable to achieve the same O.D. at 600 nm. What is the LEAST likely cause for this discrepancy in measured turbidity?

• A) One experiment used 16 mm wide test tubes while the other used 18 mm wide test tubes.
• B) One experiment subtracted the yellow color of the growth medium away from the final turbidity reported whereas the other used colorless water.
• C) One experiment vigorously dispersed the bacterial pellicle with vortexing while the other did not.
• D) The two experiments were carried out at vastly different elevations and did not consider the influence of pressure.

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Definitions:

Prejudice

Preconceived opinion not based on reason or actual experience, often directed towards people or groups.

Outgroup

A social group with which an individual does not identify, often seen as different from or in competition with one's own ingroup.

Cohesive Group

A group in which members exhibit strong bonds, loyalty, and mutual support, often leading to higher group effectiveness.

Lowball Technique

A persuasion and negotiation tactic where an item or service is offered at a lower price than is actually intended to be charged, after which the price is increased to take advantage of the customer's commitment.