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96 terms

Micro 7-8

STUDY
PLAY
Which is of the following is most likely the number of base pairs in a bacterial chromosome?
4,000,000
Which of the following is a true statement concerning prokaryotic chrmosomes?
They are located in the cytosol
A plasmid is
Extrachromosomal DNA.
Which of the following forms ionic bonds with eukaryotic DNA and stabilizes it?
Histone
Nucleotides used in the replication of DNA
All of the above
Which of the following molecules functions as a proofreader for a newly replicated strand of DNA?
DNA polymerase III
The addition of CH3 to a cytosine nucleotide after DNA replication is called
Methylation
In translation, the binding site through which tRNA molecules leave is called
E site
The Ames test
Uses autotrophs and liver extract to reveal potential mutagens.
Which of the following methods of DNA repair involves enzymes that recognize and correct nucleotide errors in unmethylated strands of DNA?
mismatch repair
Which of the following is not a mechanism of natural genetic transfer and recombination?
transcription
Cells that have the ability to take up DNA from their environment are said to be?
competent
Which of the following statements is true?
Conjugation requires a sex pilus extending from the surface of a cell.
Which of the following are called jumpin genes?
transposons
Although cells P and Q are totally unrelated, cell Q receives DNA from cell P and incorporates this new DNA into its chromosome. This process is
horizontal gene transfer
Which of the following is part of each molecule of mRNA?
codon
A nucleotide is composed of?
All of the above
In DNA, adenine forms_______ hydrogen bonds with________.
two/thymine
A sequence of nucleotides formed during replication of the lagging DNA strand is?
an Okazaki fragment
Which of the following is NOT part of an operon?
ORIGIN
Repressible operons are important in regulating prokaryotic
RNA transcription
Transcription produces
RNA molecules
Ligase plays a major role in
lagging strand replication
before mutations can affect a population permanently, they must be
all of the above
the trp operon is repressible. This means it usually ________ and is directly controlled by__________.
active/ a repressor
The three steps in RNA transcription are
initiation of transcription, elongation of the RNA transcript, termination of transcription
A triplet of mRNA nucleotides that specifies a particular amino acid is called
codons
Three effects of point mutations are
silence, missense, nonsense
Insertions and deletions in the genetic code are also called_________ mutations
frameshift
an operon consists of _______,_________, and _________ and is associated with a regulatory gene.
promoter, operator, a series of genes
In general, _________ operons are inactive until the substrate of their genes polypeptides is present
incucible
A daughter DNA molecule is composed of one original strand and one new strand because DNA replication is _________
semiconservative
A gene for antibiotic resistance can move horizontally among bacterial cells by ________, ____________, and ___________.
transformation, transduction, bacterial conjugation
_____________ are nucleotide sequences containing palindromes and genes for proteins that cut DNA strands.
Transposons
________ _________ is a recombination event that occurs during gamete formation in eukaryotes.
crossing over
____________ RNA carries amino acids
Transfer
___________ RNA and _______ RNA are antisense; that is they are complementary to another nucleic acid molecule
Short interference, Micro
Which of the following statements is true concerning recombinant DNA technology?
in involves modification of an organism's genome
A DNA gene synthesized from an RNA template is
complementary DNA
After scientists exposed cultures of penicillium to agents X,Y, and Z they examined the type and amount of penicillin produced by the altered fungi ti find the one that is most effective. Agents X,Y, and Z were probably
mutagens
Which of the following is FALSE concerning vectors in recombinant DNA technology?
Vectors must contain genes for self-replication.
which recombinant DNA technique is used to replicate copies of a DNA molecule?
PCR
which of the following would be most usefull in following a gene expression in a yeast cell?
DNA microarray
Which of the following techniques is used regularly in the study of genomics?
Fluorescent nucleotide bases are sequenced
Restriction enzyme HhaI
cuts DNA at a specific nucleotide sequence.
Which application of recombinant DNA technology involves the production of a distinct pattern of DNA fragments on a gel?
genetic fingerprinting
A DNA microarray consists of
single stranded DNA localized on a substrate
T/F.........Restriction enzymes inhibit the movement of DNA
F. .... restriction enzymes cut DNA at specific sites
T/F...... Restriction enzymes act at specific nucleotide sequences within a double stranded DNA molecule
T
a thermocyler seperates molecules based on their size, shape and electrical charge.
F....... Electrophoresis,
Protoplast fusion is often used in the genetic modification of plants
True
Gel electrophoresis is used in DNA microarrays
F.... Southern blotting
All of the following are associated with nucleic acid structure except
Ionic bonds
Which of the following is found at the 5 end of a DNA strand?
a phosphate group
The bacterial chromosome is
both circular and found in a nucleoid
Which of the following statements is true of bacterial plasmids
They are small circular DNA molecules that can replicate autonomously
Which of the following is involved in translation?
mRNA, rRNA and tRNA are all involved
the AUG codon functions in coding for the amino acid methionine and as a
start signal
Semiconservative DNA replication means that
each daughter DNA molecule is composed of one original strand and one new strand
which of the following are considered to be frameshift mutations?
both deletions and insertions
if the codon AAA is changed to AAG, it still codes for the amino acid lysine; this is an example of a
silent mutation
the ames test proves that a chemical is
mutagenic in salmonella
the horizontal transfer process known as transduction
involves a virus
in conjugation, F+ cells
contain an F plasmid
Which of the following is characteristic of prokaryotic genomes but NOT eukaryotic genomes?
cirrcular chromosomes
Which of the following processes is involved in the "central dogma" of genetics?
transcription and translation
Which of the following causes mutations by creating thymine dimers?
Ultraviolet light
Which of the following is a DNA repair enzyme activated by visible light?
DNA photolyase
The horizontal transfer process known as transduction
involves a virus
Another term for the palindromic sequence found at the ends of transposons is a
inverted repeat
The energy required for DNA replication comes from
triphosphate deoxyribonucleotides
T/F Prokaryotic cells are diploid
F
T/F the structure of DNA explains both its ability to encode genetic information and the way in which it is copied during cell reproduction
T
T/F the phenotype of an organism reflects only part of its genotype
T
T/F in generalized transduction, viruses carry random DNA sequences from one cell to another
T
A________ is a specific sequence of nucleotides that codes for a protein or an RNA molecule
Gene
Transfer of DNA between cells by viruses is called
Transduction
A mutation that changes the reading frame of a gene is called a _________ mutation
Frameshift
The _________ of a transfer RNA molecule is complementary to a codon in a messenger RNA molecule.
Anticodon
The__________ is the set of genes in the genome of an organism
Genotype
Which of the following items is not a part of the name of a restriction enzyme?
the Gram reaction of the source bacterium
The natural role of restriction enzymes in bacteria is
to protect the cell from invading phages
Put the following steps in the correct order needed to produce a recombinant vector containing a human gene insert
1. Isolate
2. Ligate
3. Introduce
4. grow bacterial cells
If a researcher used Escherichia coli DNA polymerase instead of Thermus aquaticus DNA polymerase in the PCR procedure, what would be the result?
PCR would stop after one cycle
If you started with a single DNA molecule, how many would you have at the end of six PCR cycles?
64?
In gel electrophoresis, DNA molecules move toward the ________ electrode because they have an overall ________ charge
positive, negative
Which of the following devices is used for PCR?
a thermocycler
A library of cloned sequences representing the expressed genes of an organism is known as a
cDNA library
Which of the following would be an appropriate temperature for the first step of PCR?
94C
Which of the following methods of inserting DNA into cells might be used on plant seeds?
Injection
The process of introducing animal organs into the human body is
Xenotransplantation
If all the following DNA fragments were analyzed on an electrophoresis gel, which one would migrate farthest from the negative electrode?
250 base pairs
T/F Gene therapy for human genetic diseases has not been successful yet.
F
T/F Reverse transcriptase synthesizes a DNA molecule from an RNA template.
T
T/F the number of DNA molecules produced during PCR increases exponentially
T
T/F nucleic acid molecules used to deliver new genes to cells are called transporters
F