Question

The universal regulatory mechanism in eukaryotes for controlling gene expression includes A. control of the processing of mRNA after it is transcribed from DNA but before it leaves the nucleus, and control of the rate it leaves the nucleus. B. control of the genes transcribed and the rate they are transcribed. C. control of mRNA in the cytoplasm after it leaves the nucleus, including changes to mRNA before translation begins. D. control of polypeptides after they have been synthesized but before they are functional. E. All of these mechanisms are used; there is no single universal mechanism.

Answer 1

Answer:

E. All of these mechanisms are used; there is no single universal mechanism.

Explanation:

Gene expression is regulated at many levels. Some of them are:

• Chromatin remodeling regulation includes altered histone modifications such as methylation which can regulate gene expression (up or down).

• Transcription is regulated via transcriptional factors and specificity factors such as repressors and activators.

• RNA processing can be regulated through the alternative splicing (different introns can be excised and combinations of different exons connected)

• Post-translational modification refers to modification of proteins after being synthesized.