CHAPTER 18

REGULATION OF GENE EXPRESSION

Regulation of Gene Expression in Bacteria

  1. Briefly describe two main strategies that cells use to control metabolism.
  2. Explain the adaptive advantage of genes grouped into an operon.
  3. Using the trp operon as an example, explain the concept of an operon and the function of the operator, repressor, and corepressor.
  4. Distinguish between structural and regulatory genes.
  5. Describe how the lac operon functions and explain the role of the inducer, allolactose.
  6. Explain how repressible and inducible enzymes differ and how those differences reflect differences in the pathways they control.
  7. Distinguish between positive and negative control and give examples of each from the lac operon.
  8. Explain how cyclic AMP and catabolic activator protein are affected by glucose concentration.

The Control of Gene Expression

  1. Explain the relationship between differentiation and differential gene expression.
  2. Describe at what level gene expression is generally controlled.
  3. Explain how DNA methylation and histone acetylation affect chromatin structure and the regulation of transcription.
  4. Define epigenetic inheritance.
  5. Describe the processing of the pre-mRNA in eukaryotes.
  6. Define control elements and explain how they influence transcription.
  7. Distinguish between general and specific transcription factors.
  8. Explain the role that promoters, enhancers, activators, and repressors may play in transcriptional control.
  9. Explain how eukaryotic genes can be coordinately expressed and give some examples of coordinate gene expression in eukaryotes.
  10. Describe the process and significance of alternative RNA splicing.
  11. Describe factors that influence the life span of mRNA in the cytoplasm. Compare the longevity of mRNA in prokaryotes and in eukaryotes.
  12. Explain how gene expression may be controlled at the translational level and post-translational level.

Differential Gene Expression and Mechanisms of Pattern Formation

  1. Distinguish between determination and differentiation. Explain why determination precedes differentiation.
  2. Describe the molecular basis of determination.
  3. Describe how gradients of morphogens may specify the axes of developing Drosophila embryos.
  4. Describe how homeotic genes define the anatomical identity of the segments of a developing organism.