1) Describe how the lac operon is regulated when glucose is absent but lactose
is present. Include reference to c-AMP, Catabolic Activating Protein, the operator,
RNA polymerase, and the repressor protein. 2) The trp operon is a bit more complicated. Curiously, in involves the effects
of simultaneous translation on the formation of hairpin loop structures that
may or may not interrupt transcription. Do one better than I did in lecture,
and explain how the presence or absence of trp influence translation, the formation
of loops in the RNA, and the progression of transcription. 3) As you might suspect, energetically efficient regulation of gene activity
is under strong selection. In other words, organisms that waste energy making
proteins they don't need have less energy to spend on reproductive success and
are at a selective disadvantage. Explain the energetic efficiency of the lac
operon in this context, explaining why the operon is only ON when glucose concentrations
are LOW and lactose cocnentrations are HIGH. Address both effects (why it is
adaptive to be off if glucose is high and adaptive to be off is lactose is low). 4) From a regulatory standpoint, why should we expect gene regulation to be
more complicated in multicellular eukaryotes than in prokaryotes?
(The bold-face is a hint... : ) ) 5) How does the presence of multiple transcription binding sites influence
gene regulation in eukaryotes? In other words, what doe this allow for? 6) What are enhancers and silencers, and how can distant sequences be invovled in direct regulation of Polymerase binding and activation? 7) What is the relationship between homeoboxes, homeotic genes, and homeotic
proteins? 8) The split-gene structure of eukaryotes allows for an additon "step"
of genetic regulation.... the transcript processing stage. Describe what happens
to the CT/CGRP gene in thyroid and nerve cells. 9) What are siRNA's and miRNA's, and how can they influence m-RNA processing
and gene expression? 10) What do the homeotic "hox" genes coordinate? How does their spatial
arrangement in the genome correspond to the pattern of gene action in the organism? 11) How doe the maternal genome affect early development in Drosophila? 12) Development requires cell specialization and something else.... what else? 13) How do maternal proteins influence the activity of zygotic 'gap' genes? 14) How do cells co-ordinate their development with other cells? Include a
reference to signal transduction pathways. 15) How does the first step in tissue differentiation occur in the development
of the vulva in C. elegans - between two cells that are initially identical? 16) There are developmental genes in plants, too, that cause differentiation
of "whorls" of tissue in a flower bud. What four types of structures
are encoded four by these developmental genes? Regulation and Development