164 Review Questions
4. Control of gene expression in eukaryotic cells occurs at which level(s)?
- only the transcriptional level
- epigenetic and transcriptional levels
- epigenetic, transcriptional, and translational levels
- epigenetic, transcriptional, post-transcriptional, translational, and post-translational levels
5. Post-translational control refers to:
- regulation of gene expression after transcription
- regulation of gene expression after translation
- control of epigenetic activation
- period between transcription and translation
6. How does the regulation of gene expression support continued evolution of more complex organisms?
- Cells can become specialized within a multicellular organism.
- Organisms can conserve energy and resources.
- Cells grow larger to accommodate protein production.
- Both A and B.
7. If glucose is absent, but so is lactose, the lac operon will be ________.
- activated
- repressed
- activated, but only partially
- mutated
8. Prokaryotic cells lack a nucleus. Therefore, the genes in prokaryotic cells are:
- all expressed, all of the time
- transcribed and translated almost simultaneously
- transcriptionally controlled because translation begins before transcription ends
- b and c are both true
9. The ara operon is an inducible operon that controls the breakdown of the sugar arabinose. When arabinose is present in a bacterium it binds to the protein AraC, and the complex binds to the initiator site to promote transcription. In this scenario, AraC is a(n) ________.
- activator
- inducer
- repressor
- operator
10. What are epigenetic modifications?
- the addition of reversible changes to histone proteins and DNA
- the removal of nucleosomes from the DNA
- the addition of more nucleosomes to the DNA
- mutation of the DNA sequence
11. Which of the following are true of epigenetic changes?
- allow DNA to be transcribed
- move histones to open or close a chromosomal region
- are temporary
- all of the above
12. The binding of ________ is required for transcription to start.
- a protein
- DNA polymerase
- RNA polymerase
- a transcription factor
13. What will result from the binding of a transcription factor to an enhancer region?
- decreased transcription of an adjacent gene
- increased transcription of a distant gene
- alteration of the translation of an adjacent gene
- initiation of the recruitment of RNA polymerase
14. A scientist compares the promoter regions of two genes. Gene A’s core promoter plus proximal promoter elements encompasses 70bp. Gene B’s core promoter plus proximal promoter elements encompasses 250bp. Which of the scientist’s hypotheses is most likely to be correct?
- More transcripts will be made from Gene B.
- Transcription of Gene A involves fewer transcription factors.
- Enhancers control Gene B’s transcription.
- Transcription of Gene A is more controlled than transcription of Gene B.
15. Which of the following are involved in post-transcriptional control?
- control of RNA splicing
- control