BSC 2010 Chapter Notes - Chapter 11: Provirus, Covalent Bond, Nucleosome

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emeraldantelope151

25 Feb 2017

School

University of Florida

Department

Biology - Biological Sciences

Course

BSC 2010

Professor

Mi- Jeong Yoo

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Document Summary

Concept 11. 1 many prokaryotic genes are regulated in operons. Genes are subject to positive and negative regulation. At every step of the way from dna to protein, gene expression can be regulated. An important form of gene regulation is at the level of transcription. Gene expression begins at the promoter (region of dna containing the site where rna polymerase binds to initiate transcription) Two types of regulatory proteins (called transcription factors) control whether or not a gene is active: In negative regulation, a repressor binds a specific site in or near the promoter to prevent transcription. In positive regulation, the binding of an activator stimulates transcription. Regulating gene transcription is a system that conserves energy. Prokaryotes conserve energy and resources by making certain proteins only when they are needed; have evolved mechanisms to rapidly alter the expression levels of certain genes when conditions warrant.

Related Questions

1 DNA sequences found in introns provide [A] amino acid sequence information.

[B] regulatory information.
[C] no known useful information.

[D] structure for the gene.
[E] alternative DNA splicing possibilities.

3. The TATA box is a(n)
[A] sequence close to the promoter region of many genes.
[B] square-shaped sequence.
[C] enhancer consensus sequence.
[D] activator sequence necessary for proper translation.
[E] None of the above

5. Regarding genes and gene expression, which of the following is not a difference between prokaryotes and eukaryotes
[A] Eukaryotic DNA does not contain a TATA box close to the initiation site as does prokaryotic DNA.

[B] In eukaryotes, RNA polymerase requires

'transcription factors'or initiation.

[C] Prokaryotic genes are often grouped together in

operons.

[D] In eukaryotes, the regulation of several genes at once requires common control elements in each of the genes.
[E] There is a diversity of eukaryotic polymerases that is reflected in the diversity of eukaryotic promoters.

10) In eukaryotic cells, a repressor

[A] is made of DNA.
[B] binds to the enhancer region to block transcription. [

C] is located both upstream and downstream from the promoter.
[D] binds to the operator to block RNA polymerase.

[E] binds to a silencer to reduce transcription rates.

Coordinated regulation of genes in eukaryotic cells [A] is the result of positioning the same regulatory sequence in front of each gene.
[B] results from all of those genes being under the control of one promoter.

[C] occurs because related genes all have the same

operons.
[D] occurs because enhancers cause DNA to bend.

1.) What type of control best describes the lac operon when it is regulated by allolactose? Explain the features of this type of regulation using the lac operon as an example.

2.) What is positive gene regulation?

a) when an activator protein binds to the operator of a gene to turn expression off

b) when a repressor protein binds to the operator of a gene to turn expression off

c) when an activator protein binds to the operator of a gene to turn expression on

d) when a repressor protein binds to the operator of a gene to turn expression on

e) when a protein binds to DNA to change gene expression

3.) In the lactose operon of E. coli, what is the function of each of the following genes or sites: a) regulator, b) operator, c) promoter, d) structural gene Z and e) structural gene Y?

a) regulator gene

b) operator

c) promoter

d) structural gene Z

e) structural gene Y

4.) In a negative, repressible regulatory mechanism, transcription of the structural gene(s) occurs in

a) the presence of the co-repressor, but not in its absence.

b) the absence of the co-repressor, but not in its presence.

c) the presence of the inducer, but not in its absence.

d) the absence of the inducer but not in its presence.

e) the absence or presence of the co-repressor.

What are answers and can you explain them to me?

HELP ASAP!! please type question an answer typed for Genitics

1. What are microRNAs? lncRNAs? What are some different ways that gene
expression can be regulated at the level of translation?
3.. Define positive and negative gene regulation; combinatorial control? How can one
transcription factor function as both an activator and a repressor?

4. How does the regulation of histones and chromatin control gene expression?
What is the function of HATs, HDACs and methyltransferases?
5. How is it possible for epigenetic âmarksâ to be inherited that are not part of the
DNA sequence?

BSC 2010 Chapter Notes - Chapter 11: Provirus, Covalent Bond, Nucleosome

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