A Space Probe Returns with a Culture of a Microorganism

question 14

Multiple Choice

A space probe returns with a culture of a microorganism found on a distant planet. Analysis shows that it is a carbon-based life-form that has DNA. You grow the cells in 15N medium for several generations and then transfer them to 14N medium. Which pattern in the figure would you expect if the DNA was replicated in a conservative manner?

• A) A
• B) B
• C) C
• D) D

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Definitions:

Restrictive

Imposing limitations or conditions on something's scope, use, or extent.

Nonrestrictive

Describing a clause or phrase that provides additional information without limiting the meaning of the sentence.

Nonrestrictive Clause

A type of clause in a sentence that provides additional information but does not limit or restrict the meaning of the main clause.

Restrictive

A term describing clauses, rules, or adjectives that limit or define the entities they refer to more narrowly.