You Add an Unknown Phage to a Mixture of F⁺

question 42

Multiple Choice

You add an unknown phage to a mixture of F⁺ and F− cells of E. coli and plate out the bacteria. The bacterial colonies that grow are all F−. How can you explain this phenomenon?

• A) The phage bound to a receptor on the sex pilus, and therefore only infected the F⁺ cells (leaving the F− cells alone).
• B) The phage bound to a receptor on the F− cells, leaving only them alive and allowing the F⁺ cells to die off.
• C) The phage integrated (lysogenized) the F− cells, giving them a selective advantage over the F⁺ cells.
• D) F⁺ cells are uniquely susceptible to phage attack for unknown reasons.
• E) F⁺ are well known to die in the presence of any type of bacteriophage.

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Definitions:

Explanatory Variable

A variable in a statistical model that is believed to cause or influence changes in a response variable.

Test Statistic

A test statistic is a calculated value from sample data used in hypothesis testing to determine whether to reject the null hypothesis.

Tablet Computer

A portable computing device featuring a touch-sensitive screen as its primary input device.

Sample Proportion

The proportion of individuals in a sample that have a particular characteristic, used as an estimate of the proportion in the entire population.