Unit 3
introns
After a eukaryotic mRNA has been transcribed, ____ are removed.
coiling
Elongated genomes may fit inside the minuscule volumes of a cell because of the complex ____
In RNA uracil replaces thymine; RNA is single stranded
How does RNA differ from DNA....
operans
Prokaryotic DNA is arranged into systems called ___
Cytoplasm
Protein synthesis takes place in the ____ of bacterial cells.
rRNA
This type of RNA forms part of the ribosome
guanine pairs with uracil
All of the following pertain to nitrogenous bases except
occurs on a ribosome in the cytoplasm.
All of the following pertain to transcription, except it
posttranslational modifications
Alterations to a protein made after translation, such as removal of f-met, addition of cofactors and joining with... ___ ____
inducible
An ___ operan, such as the lac operan....
polymerase
An enzyme that is named for its ability to build strands of DNA is DNA _____
The plasmid is intergrated into the chromosome of an Hfr cell but not in a F+ cell
How do an Hfr cell and a F+ cell differ?
fungi; bacteria
Plasmids are found in which types of organisms?
prokaryotic ribosomes are 70S rather than 80S
Protein synthesis is more effecient in prokaryotes than in eukaryotes for all the following reasons except?
excision
Protein that remove incorrect bases and replace them with correct ones are termed ____ repair enzymes.
anticodon
The ___ of tRNA is complimentary to mRNA codon in translation.
redundacy
The ___ of the genetic code results in several codons encoding the same amino acids.
start
The ____ codon AUG of mRNA is associated with the tRNA anticodon UAC and the amino acid methionine.
template
The ____ strand of DNA contains the order of nucleotides that are transcribed into RNA
ames
The ____ test used to determine...
genotype; phenotype
The entire genetic makeup of an organism is its ____ , but the expression of certain genetic traits are known as its ____
chloroplasts; mitochondria; plasmids; chromosomes
The genome of a prokaryotic or eukaryotic cell includes DNA found in which sites?
transposons
The jumping of a gene from one location to another is done by
control; structural
The lactose operon is composed of the regulator, the ___ locus, and the ___ locus.
RNA polymerase
The large enzyme complex involved in synthesizing RNA from a DNA templete is which of the following?
start
The mRNA sequence AUG....
RNA polymerase
The main enzyme responsible for transcription is
frameshift mutation
The most serious type of mutation is
wild type
The native or ____ strand describes cells that carry nonmutated DNA.
lagging
The newly forming DNA strand that is discontinously replicated in segments...
thymine; adenine; guanine; cytosine;
The nitrogenous bases found in DNA
ribose
The pentose sugar found in RNA
excision repair
The process in which mutations are removed and the correct bases added is called
rRNA
The prokaryotic ribosome is composed of ___ and protein.
repressor
The protein product of a repressor gene is the ____....
guanine
The purine ___ pairs with the pyrimidine cytosine.
rRNA and protein
The ribosome is composed of two subunits containing
translation
The ribosome, composed of rRNA and protein, is involved in the process of ___
translated
The ssRNA of positive strand viruses come ready to be ____
triplet
The term ____ or codon, is a sequence of 3 nucleotides in mRNA, that encodes an acid.
seperation of RNA from DNA templete
The termination of transcription involves
initiation; elongation; termination
The three events of translation in order
regulator
What is the term for the gene that codes for a protein capable of repressing the operon?
replication
What must occur prior to cell division to ensure that each new cell...
prokaryotes
What type of organisms have their DNA arranged into operons?
primase
Which enzyme synthesizes primer sequences during replication initiation?
Each new DNA helix contains one parent strand and one newly synthesized strand
Which is true regarding DNA replication?
mRNA
Which molecule contains the codons for polypeptides?
nonsense
Which mutation changes an amino acid producing codon into a stop codon?
promoter; operator; structural genes
Which of the following are components of an operan in a sequence of DNA?
synthesizes an RNA molecule from DNA templete; unwinds the DNA so that transcription can take place
Which of the following are functions of RNA polymerese?
deoxyribose sugar; nitrogenous base; phosphate
Which of the following are parts of a nucleotide in DNA?
enter host cell in RNA form; smaller genomes; virus cycle occurs in cytoplasm
Which of the following are true of RNA viruses compared to DNA viruses?
formal methionine (F-Met) is removed; cofactors are added to proteins destined to become enzymes; proteins join with other proteins to form quaternary structures; a tertiary protein conformation forms
Which of the following occur during posttranslational modification?
peptide bonds form adjacent amino acids; translocation of ribosome; tRNA delivers amino acid to empty A site
Which of the following occur during translation elongation?
enzymatic breaking of bond between tRNA and polypeptide chain
Which of the following occurs during translation termination?
mRNA
Which of the following types of RNA is the transcribed version of a structural gene in DNA, that is later read for translation into protein
papillomavirus; herpesvirus; hepatitis B virus
Which of the following viruses insert their DNA into the host genome increasing the risk of cancer?
single or double stranded DNA or RNA
Which of the folowing is the genetic pattern of viral genomes?
operator
Which part of the control locus acts as an off/on switch for transcription?
photoactivaiton
Which process repairs DNA that has been damaged...
transformation
Which recombination method involves the uptake of free DNA by competent bacterial recepient cells?
leading
Which strand is replicated continuously without segments during DNA replication
3'-AAAAACCTACAT-5'
Which templete DNA sequence encodes the peptide sequence?
spontaneous mutation
Which type of mutation is due to random mistakes in replication?
inducible operon
Which type of operon is typically in the "off" position until the appropriate substrate is present?
transposons
___ are able to shift from one part of the genome to another.
tRNA
___ bring the amino acids to the ribosome.
transduction
___ involves the transfer of DNA via bacteriophages.
transformation
___ involves the uptake of free DNA by competent bacterial recipent cells.
Uracil
___ is the nitrogenous base unique to RNA molecules
transcription
___ is the process of decoding DNA into messenger RNA.
Regulatory
____ RNA may exert control on several levels....
structural
____ genes code for proteins.
eukaryotic
____ genes may be regulated during growth and development...
recombination
____ refers to the transfer of genes between donor and recepient microorganisms.
okazaki
_____ fragments are formed during DNA replication of the lagging strand.
helicase
the enzyme ___ unzips the DNA helix prior to the start of replication.
codon
A ___ is a specific sequence of 3 mRNA...
mutagen
A ___ is an agent that induces changes in DNA.
bacteriophage
A ___ serves as the vector for transduction in bacteria.
missense
A ____ mutation results in a different amino acid being incorporated into a protein, with varying results.
template
. During replication, each parent DNA strand serves as a _____ for synthesis of new DNA strands
competent
A bacterial cell described as ____ can accept soluble DNA from the surrounding environment.
generalized transduction
A bacteriophage transfers DNA of the previous host to the current host. This is an example of
cereprossor
A ___ binds to an inactive repressor to make an active repressor.
3
A codon contains how many nucleotides?
chromosome
A discrect cellular structure composed of a neatly packaged DNA molecule.
RNA
A primer of ____ is needed at the origin of nucleotide addition
5'; 3'
A strand of mRNA is contructed in the ___ to ____ direction.
mutant
An organism that has a mutation is called a ____
genotype; phenotype
An organism's genetic makeup is referred to as its ____, whereas the expression of those genes is referred to as the organism's ___
induced
Any alteration in DNA that occurs as a consequence of exposure to chemical or physical ....
base
Any nitrogen containing molecule found in DNA and RNA that provides the basis for the genetic code is a nitrogenous ____
building the DNA chain
DNA polymerase II is responsible for:
building the DNA chain
DNA polymerase III is responsible for:
II; I
DNA polymerse ___ is the main..... wherease DNA polymerse _____
1;1
DNA triplet encodes ____ codon and ___ amino acids.
genes
There are approximately 4,200 ____ in the chromosome of escherichia cell.
pilus
Donor and recipient bacterial cells are connected by the sex ___ during conjuction
semiconservative
During ____ DNA replication the newly made double...
translation
During ____ mRNA is converted into a protein.
primase
During replication initiation, the enzyme ___ synthesizes primer sequences.
replication
During semiconservative ___ the DNA is duplicated prior to binary fission.
elongation
During transcription _____, RNA polymerase moves along the DNA strand, adding complementary...
RNA; DNA
During transcription, RNA polymerase synthesizes ____ from a ____ templete.
operons
Gene expression can be regulated through inducible or repressible ____
DNA polymerese
Gene regulation can involve a protein repressor that blocks _____ from initiating transcription
pore in cell wall
Gram positive cells conjugate and transfer genetic material...
thymine; guanine
In DNA, adenine pairs with __, wheares cystosine pairs with ___
plasmid
In bacterial conjugation, F+ donor cells are high frequency recombinant (Hfr) cells when the ___ is....
F-
In bacterial conjugation, which term refers to a recipent cell that does not have a fertility plasmid?
binding of RNA polymerese to promoter region
Initiation of transcription involves:
RNA polymarase II
Large enzyme complex involved in synthesizing....
3'
Nucleotides can only be added to the ___ end of a growing chain.
transcription; translation
One reason protein synthesis is more effecient in prokaryotes than in eukaryotes because prokaryotic ___ and ___ are simultaneous.
enzymes; structural molecules
Proteins contribute to the phenotype of an organism by functioning as
smaller
RNA virus genomes are usually ____ than DNA virus genomes.
reverse transcriptase
Retroviruses contain the enzyme ___ ____
oncogenic
Several DNA viruses are known to be initiators of cancers and are thus termed ___
mRNA
The RNA form that contains the transcribed code for a protein from the original DNA strand is mRNA.
transfer RNA
The RNA molecules that carry amino acids to the ribosomes during protein synthesis are called
termination
The region of DNA that signals the end of an RNA transcript is the ____ sequence.
tRNA
The RNA type that transfers amino acids to the growing peptide chain in translation is ___
nitrogenous
The ___ bases are either purines or pyrimidines.
RNA polymerese; promoter
The initiation of transcription occurs when ____ ____ recognizes and binds to a region of DNA....
cytosine
Thymine and ___ are pyrimidines found in DNA.
cytoplasm; nucleus
Transcription occurs in the ___ of bacteria and the ___ of yeast cells.
a bacteriophage
Transduction occurs through
false
True or False: The promoter of an operon is the location where RNA polymerase binds....
ribosome
Two subunits of the ____ compose the site...
corepressor
What binds with an inactive repressor to make...
DNA encodes RNA which encodes protein
What is the central dogma hypothesis of genetics?
abnormal bonding between adjacent pyrimidines
What is the main effect of ultraviolet radiation on DNA?
ligase
Which enzyme completes the final sealing of nicks in a newly synthesized DNA strand?
continuous; discontinous
___ (leading strand).... ___ (lagging strand)
introns
___ are DNA sequences that do not encode protein, but may have regulatory function.
mutagen
defines a chemical or physical agent that induces change in DNA
plasmid
small circular segment of DNA found in the cytoplasm of