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

Question

Quizplus · Accepted Answer

Genes that code for regulatory proteins are often expressed constitutively because these proteins are required at all times to maintain basic cellular functions and respond to changes in the cell's environment. Regulatory proteins include transcription factors and enzymes involved in signaling pathways, which are essential for the constant regulation of gene expression and other cellular processes.

Although the Expression of Most Genes Is Tightly Regulated, Some