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:

Simp

A slang term often used to describe someone who performs excessive sympathy or attention toward another person, sometimes in pursuit of a romantic relationship, without receiving any affection in return.

Add

To join something to something else so as to increase the size, number, or amount.

Simp

A pejorative slang term referring to someone who performs excessive sympathy and attention toward another person, often for little or no return.

Conj

A conjunction or connecting term that combines sentences or terms in logic or grammar.