Chapter 15
Quiz
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Art
Part 4: Genomic Analysis
Gene Mutation, DNA Repair, and Transposition
Review
A
mutation
is a
in DNA sequence and can occur
spontaneously
or be
by an external agent (mutagen).
shifts
in nucleotides can result in
mutations due to anomalous base
pairing.
DNA base
damage
by
can also lead to mutation.
Other chemical mutagens include
agents
which donate an alkyl group to nucleotides.
In general, base
can lead to
mutations during DNA
replication.
dyes cause
mutations by
intercalating
between purines and pyrimidines.
High energy
radiation
such as
(UV) light,
rays,
rays, and
rays are also
mutagenic.
repeat
sequences can cause several human genetic disorders.
The
test uses bacteria selected for their sensitivity to specific types of mutagenesis to screen compounds for potential
mutagenicity.
repair
can restore gaps created during DNA
replication
due to damaged nucleotides.
repair
in prokaryotes can remove thymine dimers caused by UV light.
Two types of excision repair can also repair damaged DNA:
excision
repair
(BER) and
excision
repair
(NER).
elements
(transposons or "jumping genes") can move within the
genome.
The
(Activator) elements contain a
gene
similar to that of
bacterial
sequences and
transposons.
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Dec 2, 2008
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