Chapter 19 Guiding Questions
mcourtney 27 Jan 2008 22:48
The Structure of Eukaryotic Chromatin
- Compare the structure and organization of prokaryotic and eukaryotic genomes.
- Describe the current model for progressive levels of DNA packing in eukaryotes.
- Explain how histones influence folding in eukaryotic DNA.
- Distinguish between heterochromatin and euchromatin.
The Control of Gene Expression
- Explain the relationship between differentiation and differential gene expression.
- Describe at what level gene expression is generally controlled.
- Explain how DNA methylation and histone acetylation affect chromatin structure and the regulation of transcription.
- Define epigenetic inheritance.
- Describe the processing of pre-mRNA in eukaryotes.
- Define control elements and explain how they influence transcription.
- Distinguish between general and specific transcription factors.
- Explain the role that promoters, enhancers, activators, and repressors may play in transcriptional control.
- Explain how eukaryotic genes can be coordinately expressed and give some examples of coordinate gene expression in eukaryotes.
- Describe the process and significance of alternative RNA splicing.
- Describe factors that influence the life span of mRNA in the cytoplasm. Compare the longevity of mRNA in prokaryotes and in eukaryotes.
- Explain how gene expression may be controlled at the translational and post-translational level.
The Molecular Biology of Cancer
- Distinguish between proto-oncogenes and oncogenes. Describe three genetic changes that can convert proto-oncogenes into oncogenes.
- Explain how mutations in tumor-suppressor genes can contribute to cancer.
- Explain how excessive cell division can result from mutations in the ras proto-oncogenes.
- Explain why a mutation knocking out the p53 gene can lead to excessive cell growth and cancer. Describe three ways that p53 prevents a cell from passing on mutations caused by DNA damage.
- Describe the set of genetic factors typically associated with the development of cancer.
- Explain how viruses can cause cancer. Describe several examples.
- Explain how inherited cancer alleles can lead to a predisposition to certain cancers.
Genome Organization at the DNA Level
- Describe the structure and functions of the portions of eukaryotic DNA that do not encode protein or RNA.
- Distinguish between transposons and retrotransposons.
- Describe the structure and location of Alu elements in primate genomes.
- Describe the structure and possible function of simple sequence DNA.
- Using the genes for rRNA as an example, explain how multigene families of identical genes can be advantageous for a cell.
- Using a-globin and b-globin genes as examples, describe how multigene families of nonidentical genes may have evolved.
- Define pseudogenes. Explain how such genes may have evolved.
- Describe the hypothesis for the evolution of a-lactalbumin from an ancestral lysozyme gene.
- Explain how exon shuffling could lead to the formation of new proteins with novel functions.
- Describe how transposition of an Alu element may allow the formation of new genetic combinations while retaining gene function.