Apentix/AP Biology/Unit 7: Natural Selection/Question
AP Biologyeasymcq1 pt

A population of bacteria is exposed to an antibiotic. Initially, most of the bacteria die, but a small fraction survives. Over several generations, the entire population is resistant to the antibiotic. Which mechanism best explains this phenomenon?

Explanation

Core Concept

This is correct because it describes natural selection (often termed 'survival of the fittest'). The random pre-existing trait of resistance became highly favorable in the new environment, leading to differential reproductive success.

Correct Answer

q5_survival

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