In Prokaryotes, the Genes for Metabolic Pathways Are ____

question 32

Multiple Choice

In prokaryotes, the genes for metabolic pathways are ____.

• A) always expressed for early steps in the pathway, but generally not expressed for later steps in the pathway
• B) always expressed so the bacteria can respond to rapidly  changing conditions
• C) turned on and off as conditions change
• D) always independently regulated
• E) generally expressed at low levels, but expressed at high levels when conditions warrant

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Definitions:

Selection

The process by which certain traits become more or less common in a population due to their impact on the reproductive success of their bearers.

Directional Selection

A form of natural selection in which individuals with traits on one end of the spectrum are more likely to survive and reproduce, leading to an overall shift in the population.

Stabilizing Selection

An evolutionary process that favors the average variants in a population, leading to a decrease in diversity for the trait in question.

Disruptive Selection

Disruptive selection favors individuals at the tails of the distribution of phenotypes present in a population (for example, by acting against individuals with intermediate trait values).