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Unformatted text preview: LEARNING OBJECTIVES Use the following learning objectives to guide your reading and studying of the material for BIOL 2040. Ch 13 & Ch 18 After reading the assigned portions of Chapter 13 and 18 you should be able to: Explain how different tissues and different cells have expression of different genes, when every cell (barring mature red blood cells) carries the same genomic information. Describe, briefly, the phenomenon of chromatin remodelling. Describe a nucleosome and its components. Describe the types of organisms in which you would find chromatin remodelling. Describe the level of transcription of naked DNA (i.e., has no nucleosomes). Describe the effects of nucleosomes on transcriptional levels. Describe the location of nucleosomes for most transcriptionally inactive genes. Describe the relative sensitivity to DNase of transcriptionally active & transcriptionally inactive DNA. Explain how transcriptionally active DNA can still have nucleosomes present. Describe the changes that must occur with respect to nucleosomes to make transcriptionally inactive DNA to transcriptional active DNA. Identify the two major types of chromatin remodelling complexes (that we looked at). Describe the effects of complexes that disrupt nucleosome structure near promoters. Describe the effects of histone acetyltransferases. List the 3 major locations of heterochromatin. Differentiate between facultative and constitutive heterochromatin. Compare, briefly, the structure and function of euchromatin & heterochromatin. Define gene silencing. Describe two changes to chromatin to change it from an active to an inactive state. Describe methylation of DNA with respect to where it occurs and what its affects are. Describe how we could analyse the methylation of a gene. Compare and contrast sex differences in X‐chromosome gene dosage of humans, Drosophila, and C. elegans. Define Barr body. Describe circumstances under which you would find a Barr body in the cells of a human male, or would not find a Barr body in the cells of a human female. Describe the pattern of X‐chromosome inactivation in the early embryo and its impact on cell lineages. Describe, in general terms, the mechanism for X chromosome inactivation in mammals in particular the relative roles of XIST and TSIX. Describe the consequences of an non‐functional (or missing) XIST or TSIX gene on one of the X chromosome homologues in a mammalian female. Describe why sex chromosome aneuploids have a greater chance of survival relative to aneuploidy involving many other types of chromosomes. Describe why sex‐chromosome aneuploids may be viable, but still display abnormalities. ...
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This note was uploaded on 01/10/2010 for the course BIOLOGY biol2040 taught by Professor Tamarakelly during the Fall '09 term at York University.
- Fall '09