Although the Expression of Most Genes Is Tightly Regulated, Some

question 13

Multiple Choice

Although the expression of most genes is tightly regulated, some genes are expressed at roughly constant rates. Which of the following genes would you predict to be constitutively (constantly) expressed?

• A) genes involved in the biosynthesis of the amino acid tryptophan
• B) genes involved in the degradation of tryptophan
• C) genes involved in the degradation of arabinose, a sugar
• D) genes that code for regulatory proteins

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Definitions:

Need

A requirement for something because it is essential or very important.

Drive-reduction Theory

A psychological motivation theory suggesting that the act of fulfilling basic physiological needs reduces drive and generates a state of psychological equilibrium or satisfaction.

Famine

A severe shortage of food resulting in widespread hunger, malnutrition, and increased mortality.

Arousal Theory

The theory suggesting that people are motivated to maintain an optimal level of arousal for their best performance.