41 terms

Mastering Biology Chapter 19 Test #3

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Transcription is the process by which information encoded in DNA is converted to information encoded in ____.
RNA
With RNA processing, introns have been __________ and a cap and a _____ have been added to the RNA molecule.
removed

tail
In eukaryotes, the first step in the control of gene expression is _____________ _________________.
chromatin remodeling
In eukaryotes, DNA is wrapped around proteins to create a structure called ____________.
chromatin
Before transcription can occur, the DNA must be bound less _________ to the proteins so that RNA polymerase can access the ____________
tightly

promoter
RNA polymerase attaches to ______.
DNA
The addition of acetyl groups to histones is associated with chromatin _________________ and __________ levels of gene expression
.
decondensation

higher
Acetyl groups __________ the association between DNA and histones, which results in higher levels of transcription.
loosen
Why does chromatin remodeling have to be the first step in gene activation?

Eukaryotic DNA can be highly packaged in condensed chromatin and inaccessible to _______________ factors and ______ Polymerase.
transcription

RNA
Eukaryotic DNA exists in chromatin structures in which it is inaccessible to the transcriptional machinery. As a result, chromatin ______________ must occur before transcription can.
remodeling
Muscle cells differ from nerve cells mainly because they express different _______.
genes
In a nucleosome, the DNA is wrapped around ___________.
histones
Which method is utilized by eukaryotes to control their gene expression that is NOT used in bacteria?

Control of both RNA ___________ and chromatin ______________
splicing

remodeling
What allows more than one type of protein to be produced from one gene?

Alternative forms of RNA ___________
splicing
A researcher found a method she could use to manipulate and quantify phosphorylation and methylation in embryonic cells in culture.


In one set of experiments she succeeded in increasing acetlylation of histone tails. Which of the following results would she most likely see?

activation of histone tails for enzymatic function

decreased binding of transcription factors

decreased chromatin condensation

increased chromatin condensation

inactivation of the selected genes
decreased chromatin condensation
What is most critical for the association between histones and DNA?

Histones are _____________ charged.

(DNA is negatively charged)
positively
_____________ bind to DNA enhancer regions.
Activators
Activators are a type of transcription factor that bind to ____________ regions.
enhancer
The __________ of the DNA allows for the interaction of transcription factors and RNA polymerase.
bending
Both _____ polymerase and ______________ factors bind with the promoter.
RNA

transcription
Imagine that you've discovered a regulatory sequence thousands of base pairs away from the promoter and that when this sequence is lost due to mutation, levels of gene expression decrease sharply. This sequence is most likely an _____________.
enhancer
Enhancers are present in all eukaryotes and activate ________________.
transcription
Differential gene expression is the result of different cells containing different ______________ ___________.
regulatory proteins
Regulatory proteins bind to the same regulatory sequence and control ______________ of groups of genes.
expression
What best explains why the discovery of alternative splicing forced biologists to change their definition of a gene?

It showed that a gene can direct the production of more than one specific _______________ or ______.
polypeptide

RNA
Alternative RNA splicing allows for the number of different __________ to exceed the number of different ________.
proteins

genes
Splicing the exons of an RNA transcript in different ways yields different proteins from the same ______.
gene
What is most accurate concerning how gene expression in eukaryotes compares with that in bacteria?

The number of ___________ that control transcription is much greater in eukaryotes.
proteins
The complexity of ______________ between different proteins and between proteins and DNA is much greater in eukaryotic transcriptional control than in bacteria.
interactions
In general, this reflects the greater functional _____________ of eukaryotic organisms.
complexity
The DNA in one of your brain cells is the same as the DNA in one of your _______ cells.
heart
Histone acetyl transferases exert their effect on gene activity by neutralizing positive charges on the __________ of histones
.
lysines
Chromatin is the complex of DNA and proteins found in ______________
eukaryotes
Compare and contrast enhancers and the E. coli araC binding site. What do they have in common?

Both are sites in DNA where _____________ proteins bind
regulatory
An enhancer is located at great distances from the _____________
promoter
An enhancer is _____________ in any orientation
functional
The araC site is located near the ____________
promoter
Compare and contrast promoter-proximal elements and the operator of the lac operon. What do they have in common?

Both are regulatory sites in ______ located close to the ____________
DNA

promoter
Compare and contrast basal transcription factors and sigma. What do they have in common?

Both are ___________ that must bind to the ____________ before RNA polymerase can initiate transcription
proteins

promoter
Basal transcription complex __________ RNA polymerase to the ___________
recruits

promoter
Sigma is part of the RNA polymerase _______________
part
holoenzyme