transcripton and traslation of DNA biochemistry

b. have 5' to 3' polymerization activity

All known bacterial DNA polymerases _____. a. can initiate DNA chain synthesis b. have 5' to 3' polymerization activity c. have 5' to 3' exonuclease activity d. have 3' to 5' polymerization activity e. All of the above

t has proofreading capability.

All of the following are true of RNA polymerase except: A. It binds to most regions of DNA. B. It binds best to promoter regions. C. It unwinds DNA. D. It produces transient RNA-DNA hybrids. E. It has proofreading capability. F. It requires r to terminate transcription.g) It produces hairpin structures in mRNA. G. It is inhibited by rifampicin.

before Upstream is before while downstream is indicative of after if you are 'reading' a genomic sequence from left to right.

Along a gene sequence, the TATA box is usually located upstream of the transcriptional start site. In simple terms, where is the TATA box located with respect to the transcriptional start site long the gene sequence?

D) There will be glycines at all glycine positions and at all valine positions.

An aminoacyl tRNA synthase Valine is mutated so that it now attaches the amino acid glycine to the tRNA Valine instead of valine. What will happen at translation? A) There will be glycines at all valine positions and valines at all glycine positions. B) There will be valines at all glycine positions and glycines at all valine positions. C) There will be valines at all glycine positions and at all valine positions. D) There will be glycines at all glycine positions and at all valine positions. E) There will be no translation.

D) attachment of a particular amino acid to a particular tRNA.

An aminoacyl-tRNA synthetase catalyzes the: A) attachment of a particular tRNA to mRNA. B) binding of RNA polymerase to the terminator. C) binding of RNA polymerase to the promoter. D) attachment of a particular amino acid to a particular tRNA. E) attachment of a particular tRNA to the ribosome.

A) A (aminoacyl)

An incoming aminoacyl-tRNA molecule binds to the ribosome at the ______ site. A) A (aminoacyl) B) mRNA-binding C) P (peptidyl) D) E (exit) E) promoter

C) 5' to 3'

DNA and RNA are always polymerized in which direction? A) 3' to 5' B) 1' to 2' C) 5' to 3' D) carboxyl to amino terminus E) amino to carboxyl terminus

modulate transcription

Enhancers are regions that A. bind RNA polymerase B. are adjacent to the TATA box C. are CAT box binding proteins D. modulate transcription

E) is more readily transcribed during interphase.

Euchromatin differs from heterochromatin in that euchromatin: A) stains more strongly. B) is more tightly condensed. C) predominates in centromeres. D) predominates in telomeres. E) is more readily transcribed during interphase.

A) called heterochromatin and euchromatin

Eukaryotic chromosomes contain two general domains that relate to the degree of condensation. These two regions are ________. A) called heterochromatin and euchromatin B) uniform in the genetic information they contain C) void of introns D) separated by large stretches of repetitive DNA E) each void of typical protein-coding sequences of DNA

E) are translated into protein.

Exons are segments of a gene that: A) are transcribed into segments of mRNA that are snipped out before translation. B) occur in prokaryotic but not eukaryotic chromosomes. C) consist of RNA rather than DNA nucleotides. D) are not transcribed by RNA polymerase. E) are translated into protein.

mRNA

Which Type of RNA Functions as a blueprint for the genetic code • rRNA • tRNA • mRNA • RNA Polymerase

tRNA, tRNA and mRNA, tRNA, tRNA, rRNA, mRNA, mRNA

ll three forms of RNA are post-transcriptionally modified into their final form. Enter the type of RNA (mRNA, tRNA, and rRNA) that matches the modification described in each line. (More than one type of RNA may be entered per line.) __________ Trimming of 5' end by phosphodiester bond cleavage __________ Intron removal __________ Addition of CCA sequence to 3' end __________ Heterocyclic base modification __________ Methylation of bases __________ Addition of 7'-methylguanosine to the 5' end of the RNA molecule __________ Addition of poly-A tail to the 3' end of the RNA molecule

D. all of these

he nucleons of eukaryotic cell has A. RNA polymerase I B. RNA polymerase II C. RNA polymerase III D. all of these

B) transcription.

he process of copying a gene's DNA sequence into a sequence of RNA is called A) replication. B) transcription. C) translation. D) PCR.

RNA polymerase II Explanation: RNA Polymerase II is used to catalyze the polymerization of mRNA during transcription. RNA polymerase I catalyzes the polymerization of rRNA, and RNA polymerase III catalyzes the polymerization of tRNA.

hich RNA Polymerase is associated with the transcription of DNA to synthesize mRNA? RNA polymerase III All of these answers RNA polymerase II None of these answers RNA polymerase I

messenger RNA (mRNA)

nucleotide molecule that serves as an intermediate in the genetic code between DNA and protein

signal sequences There are many different posttranslational modifications to proteins that change functionality but signal sequences are the only moieties that will help target the proteins to subcellular organelles.

Following translation, proteins can be targeted to subcellular locations by:

An in frame start codon (AUG) Explanation: AUG or the start codon will determine the reading frame for a specific mRNA. See figure 15.3

For any given mRNA there are 3 reading frames. The reading frame is determined by the the presence of which of the following:

I, II, and III Explanation: Eukaryotes have three types of RNA polymerase, I, II, and III. RNA polymerase II recognizes the promoter and binds to the promoter forming a preinitiation complex. The polymerase is composed of 10-12 subunits. Transcription factors also bind the promoter (the region of DNA upstream of the start or origin of transcription).In eukaryotes sigma protein factor is not required for transcription to occur.

How does initiation of transcription occur in eukaryotes? I. In eukaryotes sigma protein factor is not required for transcription to occur. II. Transcription factors such as TFIID bind and activate the gene promoter. III. RNA polymerase II recognizes and binds the promoter of the gene to be transcribed.

downstream from the start codon

Promoters for tRNAs are located A. upstream from the start codon B. downstream from the start codon C. both (a) and (b) D. none of these

D. promoters.

The regions of a gene located at -10 and -35, with respect to the start of transcription, are termed A. start codons. B. oriC regions. C. Shine Dalgarno sequences. D. promoters.

translation initiation

process of producing a protein from the nucleotide sequence code of an mRNA transcript

transcription factors

process of producing an mRNA molecule that is complementary to a particular gene of DNA

splicing

the process of modifying a pre-mRNA transcript by removing certain, typically non-coding, regions

The first and second choices are both correct.

. Replication in E. coli is initiated by the generation of short RNA primers using RNA polymerase. primase. DNA polymerase II. reverse transcriptase. The first and second choices are both correct.

C. RNA polymerase Explanation: During DNA replication, the strands are prepared by topoisomerases to relieve torsional strain. At the replication fork, primase, choice (A), creates a primer for the initiation of replication, which is followed by DNA polymerase. On the lagging strand, Okazaki fragments form which are joined by DNA ligase, choice (C). After the chromosome has been processed, the ends, called telomeres, are replicated with the assistance of the enzyme telomerase, choice (D). RNA polymerase, distinct from primase, is responsible for transcription.

. Which of the following enzymes is NOT involved in DNA replication? A. Primase B. DNA ligase C. RNA polymerase D. Telomerase

primary transcript

A DNA sequence is read by RNA polymerase which produces complementary antiparallel RNA strand called tertiary transcript secondary transcript hexa transcript primary transcript

C) 3'-AUGCCCUAA-5'

A DNA template strand has the following sequence: 5'-TACGGGATT-3'. What is the mRNA sequence transcribed from the DNA? A) 3'-AAUCAGUTA-5' B) 3'-UACGGGAUU-5' C) 3'-AUGCCCUAA-5' D) 3'-ATGCCCTAA-5' E) 3'- TACGGGATT-5'

B) frameshift

A class of mutations that results in multiple contiguous amino acid changes in proteins is likely to be which of the following? A) transition B) frameshift C) base analog D) recombinant E) transversion

C) no, the final mRNA contains only exons, the introns were removed

A geneticist isolates a gene for a specific trait under study. She also isolates the corresponding mRNA. Upon comparison, the mRNA is found to contain 1,000 fewer bases than the DNA sequence. Did the geneticist isolate the wrong DNA? A) yes, mRNA is made from a DNA template and should be the same length as the gene sequence B) yes, the mRNA should contain more bases than the DNA sequence because bases flanking the gene are also transcribed Tr. C) no, the final mRNA contains only exons, the introns were removed D) no, the mRNA was partially degraded after it was transcribed

FALSE

A missense mutation causes premature chain (protein) termination

frameshift mutation A frameshift mutation occurs when the number of inserted or deleted is not a multiple of three will alter the reading frame of the protein.

A mutation within the genome that inserts 7 base pairs into an exon (coding region) is best described as which of the following?

E) 1800

A protein is 300 amino acids long. Which of the following could be the number of nucleotides in the section of DNA that codes for this protein? (Remember: DNA is double-stranded.) A) 3 B) 100 C) 300 D) 500 E) 1800

RNA polymerase I There are three types of RNA molecules. First, mRNA molecules are the main products of transcription that undergo translation to produce most of the proteins found in a cell. Second, tRNA molecules are special RNA molecules that facilitate the addition of amino acids to a growing polypeptide chain during translation. Third, rRNA molecules are components of ribosomes and are synthesized in the nucleolus (location of assembly of ribosomes). The enzyme in this question is involved in the production of rRNA molecules. RNA polymerase I is used in production of rRNA molecules. RNA polymerase II is used for mRNA molecules and RNA polymerase III is used for tRNA molecules.

A researcher is analyzing an enzyme. Results reveal that the enzyme is found in eukaryotes, and is involved in synthesis of ribosomes. Which of the following could be the identity of the enzyme? RNA polymerase II RNA polymerase I More than one of these could be correct RNA polymerase III

E) rRNA; protein

A ribosome consists of ______ and ______. A) DNA; mRNA B) mRNA; protein C) mRNA; tRNA D) rRNA; mRNA E) rRNA; protein

E) methionine-methionine-leucine-lysine

A short segment of an mRNA molecule is shown below. The polypeptide it codes for is also shown: 5′-AUGGUGCUGAAG-3′: methionine-valine-leucine-lysine Assume that a mutation in the DNA occurs so that the fourth base (counting from the 5′ end) of the messenger RNA now reads A rather than G. What sequence of amino acids will the mRNA now code for? (You do not need a copy of the genetic code to answer the question.) A) methionine-leucine-leucine-lysine B) methionine-lysine-leucine-lysine C) methionine-valine-methionine-lysine D) methionine-valine-leucine-lysine E) methionine-methionine-leucine-lysine

A) transition mutation

A tautomeric shift may result in _____. A) transition mutation B) transversion mutation C) frameshift mutation D) induced mutation E) any of the above

Answer: a) Transcription Explanation: The elongation of RNA strands by RNA polymerase in both bacteria and eukaryotes is inhibited by the antibiotic actinomycin D.

Actinomycin D is an inhibitor of a) Transcription b) Translation c) Replication d) None

E) RNA that is removed during RNA processing

An intron is a section of ________. A) DNA that is removed during DNA processing B) transfer RNA that binds to the anticodon C) carbohydrate that serves as a signal for RNA transport D) protein that is clipped out posttranslationally E) RNA that is removed during RNA processing

B) RNA that is removed during RNA processing

An intron is a section of ________. A) protein that is clipped out posttranslationally B) RNA that is removed during RNA processing C) DNA that is removed during DNA processing D) transfer RNA that binds to the anticodon E) carbohydrate that serves as a signal for RNA transport

D. From single DNA it can make multiple transcripts simultaneously, and each transcript can be translated into multiple proteins simultaneously

Bacteria can make a large quantity of protein for a given gene very fast. How does a bacterium accomplish this? (best answer) A. It makes multiple copies of this gene B. It can simultaneously make multiple transcripts from one copy of a gene C. It can simultaneously make multiple transcripts from one protein D. From single DNA it can make multiple transcripts simultaneously, and each transcript can be translated into multiple proteins simultaneously

three

Bacterial cells only need one type of RNA polymerase. How many RNA polymerases do eukaryotic cells have? A. none B. one C. three D. more than 10

D. False, it is not known which is least productive

Because pol I transcribes only 2 genes, it is the least productive polymerase of the three (i.e. incorporates the fewest number of nucleotides) A. True B. False C. False pol III is less productive D. False, it is not known which is least productive

Answer: a Rifampicin Explanation: Rifampicin inhibits the binding of the prokaryotic DNA dependent RNA polymerase to promoter site.

Binding of the prokaryotic DNA dependent RNA polymerase to promoter site is inhibited by a) Rifampicin b) Tetracycline c) Puromycin d) Streptomycin

FALSE

Both DNA and RNA follow Chargaff's rules of base pairing.

D. AT rich sequences more readily form open complexes

Both the TATA box and the -10 element are rich in A's and T's. Why? A. Coincidence B. They are bound by similar proteins (i.e. sigma factor and TBP) C. They are bound by totally different proteins, but the mode of binding is similar D. AT rich sequences more readily form open complexes

A. 5' exonucleases

Capping protects the mRNA from degradation by? A. 5' exonucleases B. 3' exonucleases C. endonucleases D. all nucleases

Proteins bind to specific sequences in the DNA often resulting in both the bending and unwinding of the double helix to expose unpaired purine and pyrimidine bases.

Choose the answer that correctly gives the most important change in the structure of cellular DNA for allowing the initiation of transcription as the first step in gene expression: *A. Proteins bind to specific sequences in the DNA often resulting in both the bending and unwinding of the double helix to expose unpaired purine and pyrimidine bases. B. DNA has the ability to undergo denaturation at the appropriate temperature and ionic strength of its solution environment and then to reversible renature into a double helix again. C. Double-stranded DNA has extensive secondary structure that is melted out by proteins binding to specific regulatory sequences. D. The nitrogen bases in double helical DNA are reversibly crossed linked by covalent bonds and these cross links are removed when regulatory proteins bind thus allowing strand separation and the initiation of transcription.

C. Amino acid, tRNA, ATP

Choose the answer that correctly names all three of the molecules that must be bound to amino acyl-tRNA synthetase as part of the two-step decoding process: A. Amino acid, mRNA, tRNA B. Amino acid, rRNA, tRNA *C. Amino acid, tRNA, ATP D. Amino acid, mRNA, ATP

B. Eukaryotic cells

Choose the response that correctly identifies the cells in which the 5' end of the primary transcript becomes capped and methylated: A. Prokaryotic cells *B. Eukaryotic cells C. Both prokaryotic and eukaryotic cells D. Neither prokaryotic nor eukaryotic cells

A. Prokaryotic cells

Choose the response that correctly identifies the cells in which translation starts at the 5' end of the mRNA even before the primary transcript is finished being made: *A. Prokaryotic cells B. Eukaryotic cells C. Both prokaryotic and eukaryotic cells D. Neither prokaryotic nor eukaryotic cells

C) histones

Chromatin of eukaryotes is organized into repeating interactions with protein octamers called nucleosomes. Nucleosomes are composed of which class of molecules? A) glycoproteins B) nonhistone chromosomal proteins C) histones D) H1 histones E) lipids

C. DNA polymerase makes a double stranded product (one of the strands is newly synthesized) while the product of RNA polymerase is single stranded

Compared with DNA replication, which statement about RNA transcription is correct? A. Both require a primer to start B. The product of RNA transcriptions is always shorter than DNA replication C. DNA polymerase makes a double stranded product (one of the strands is newly synthesized) while the product of RNA polymerase is single stranded D. DNA polymerases have proofreading activities while RNA polymerases don't

2, 3, 1 Explanation: Transcription is the process of producing RNA molecules from a parent strand of DNA. The first step in transcription involves the binding of a sigma factor to inactive RNA polymerase, which in turn binds to the promoter region on the DNA molecule. After the binding of RNA polymerase to the DNA promoter, RNA polymerase gets activated and removes the hydrogen bonds between nucleotides of the double stranded DNA. Finally, RNA polymerase adds complementary nucleotides to the growing RNA molecule. After completion of transcription, RNA molecules undergo post-transcriptional modifications and exit the nucleus and enter cytoplasm, where it can undergo translation.

Consider the following events in transcription: 1. RNA polymerase adds new nucleotides 2. Sigma factor binds to inactive RNA polymerase 3. Transcription bubble forms Which of the following is the correct order of these events?

C. Simple sequence DNA

DNA fingerprinting depends on differences in length of this class of DNA: A. Single-copy DNA B. Pseudogenes *C. Simple sequence DNA D. Small multigene families

C) Nucleotides

DNA is a polymer of: A) Sugar residues B) Amino acids C) Nucleotides D) Phosphates E) Amines

E) in the place of the primer RNA after it is removed

DNA polymerase I is thought to add nucleotides ________. A) to the 5′ end of the primer B) in a 5′ to 5′ direction C) to the 3′ end of the primer D) on single-stranded templates without need for an RNA primer E) in the place of the primer RNA after it is removed

to the 3′ end of the RNA primer

DNA polymerase III adds nucleotides ________. A) in the place of the primer RNA after it is removed B) to the 3′ end of the RNA primer C) to internal sites in the DNA template D) to both ends of the RNA primer E) to the 5′ end of the RNA primer

a. an RNA primer

DNA polymerase III can only add nucleotides to an existing chain, so _________________ is required. a. an RNA primer b. DNA polymerase I c. helicase d. a DNA primer EX1

FALSE

DNA replicates conservatively, which means that one of the two daughter double helices is "old" and the other is "new."

A. DNA replication (by DNA Polymerase)

DNA replication and RNA transcription both use the same DNA template. Which process is more accurate? A. DNA replication (by DNA Polymerase) B. RNA transcription (by RNA Polymerase) C. About the same, both very accurate D. About the same, both inaccurate

DNA Polymerase I and II

DNA replication is not perfect; a mistake is made for every 104 to 105 nucleotides added. However, there are proofreading enzymes that excise incorrect bases and insert the correct one. Which of the following enzymes proofread DNA? A. DNA ligase B. DNA gyrase C. DNA Polymerase I and II D. DNA Polymerase III

Increased fidelity

DNA replication is semiconservative. Why do you think this is? A. Requires less energy O B. Only one DNA strand can be copied at a time. O C. RNA primer limitations O D. DNA replication starts at specific sites only. E. Increased fidelity

Two new daughter strands

DNA replication results in: A. Protein production O B. Heavy DNA C. Two new daughter strands O D. Induced mutations O E. mRNA transcripts

OH

DNA strand breaks

true

DNA strand replication begins with an RNA primer.

A. three stem loops

Each tRNA molecule has a cloverleaf secondary structure consisting of A. three stem loops B. two stem loops C. four stem loops D. either (a) or (b)

Dimethyl sulfate

Deaminates cytosine to form uracil

Sugar. phosphate, nucleotide

Describe the structure of the DNA Molecule

D. It can perform both pyrophosphorlytic and Hydrolytic editing

Does RNA polymerase have proofreading activities? A. No, this is why the transcription process is not highly accurate B. It has one proofreading mechanism: pyrophosphorlytic editing C. It has one proofreading mechanism: Hydrolytic editing D. It can perform both pyrophosphorlytic and Hydrolytic editing

GATCCA

During Replication, a DNA strand with following bases CTAGGT will produce a DNA Strand with the bases • TCGAAC • AGCTTG • GAUCCA • GATCCA

a) DNA polymerase

During replication DNA is synthesized by _____. a) DNA polymerase b) RNA polymerase c) ribosomes d) ribozymes

DnaB, Gyrase

During replication, overwinding or overtightening of DNA is caused by __ and removed by __. DNA ligase, Gyrase DnaB, DNA polymerase DnaB, Gyrase DnaA, Gyrase Single Stranded Binding Protein, DnaA

mRNA

During translation, a ribosome binds to • DNA • mRNA • Protein • A Peptide Bond

codon

Each nucleotide triplet in mRNA that specifies a particular amino acid is called a(n) • mutagen • codon • anticodon • exon • intron

a. a chemical component of cells could introduce a new, heritable trait to a cell

Frederick Griffith's transformation experiment showed that _____. a. a chemical component of cells could introduce a new, heritable trait to a cell b. DNA is the genetic material of viruses c. DNA is the genetic material of bacteria d. DNA is the genetic material of mice e. all of the above

TATA box

Goldberg-Hogness box is alternative name for unit box RNA box TATA box DNA box

B. cDNA results from the reverse transcription of processed mRNA.

How is cDNA best characterized? A. cDNA results from a DNA transcript with noncoding regions removed. B. cDNA results from the reverse transcription of processed mRNA. C. cDNA is the abbreviation for deoxycytosine. D. cDNA is the circular DNA molecule that forms the bacterial genome.

3

How many codons are needed to specify three amino acids • 3 • 6 • 9 • 12 • It cant be done

3

How many types of RNA are there?

A. a methylated guanine cap is added to the 51 end of the transcript

Immediately after transcription A. a methylated guanine cap is added to the 51 end of the transcript B. a methylated guanine cap is added to the 31 end of the transcript C. both (a) and (b) D. a poly adenylation signal is added

ddNTPs

In DNA sequencing reactions, which of the following molecules is responsible for the chain termination reaction that results in DNA fragments? A. dNTPs B. DNA primer C. ddNTPs D. Denaturing agent E. 32P-dATP

C. It does not correct its mistakes (no proofreading)

In a sense the RNA polymerase is a "dumb" enzyme. But it is not guilty of which of the following? A. It does not initiate well B. It does not read well- pauses during elongation C. It does not correct its mistakes (no proofreading) D. It has to be bumped from the DNA (by RHO or a terminator sequence in the RNA)

The -10 box Feedback: Initiation of transcription takes place when RNA polymerase locks on to the gene at the promoter. The polymerase binds to short stretches of base sequences that are similar in many promoters. These are called 'elements' or 'boxes'. The Pribnow box is named after David Pribnow, who discovered it, and it is found around 10 base pairs upstream of the transcriptional start site, i.e. at -10. It is often referred to as the -10 box.

In bacterial promoters, which of the following describes the 'Pribnow box'? a) The 5' untranslated region b) The -10 box c) The -35 box d) The termination sequence

C. TATA box

In both eukaryotes and prokaryotes, a promoter region that is rich in AT bases is called as A. CATT B. Shine Dalgarno region C. TATA box D. SV40 region

B. RNA polymerase II

In eukaryotes, there are three different RNA polymerases. The RNA polymerase responsible for transcription of mRNA is A. RNA polymerase I B. RNA polymerase II C. RNA polymerase III D. none of these

C. the first mRNA molecule is protected at the 5' end by capping while the second RNA molecule is not

In eukaryotic transcription, after mature mRNA is released, the RNA polymerase enzyme (Pol II) continues to produce a second RNA molecule until Pol II is displaced by RNAse part 1. Why does part 1 "torpedo" this, second RNA molecule but not the first original RNA molecule? A. rat1 is only activated by the first mRNA molecule B. rat1 is only active on the RNA molecules without an open reading frame. the original mRNA contains an open reading frame, but the second RNA does not. C. the first mRNA molecule is protected at the 5' end by capping while the second RNA molecule is not D. the first mRNA molecule is protected at the 3' end by capping while the second RNA molecule is not

FALSE

In ligase-deficient strains of E. coli, DNA and chromosomal replication are unaltered because ligase is not involved in DNA replication.

a core promoter sequence must be presen

In order to initiate transcription in eukaryotes a core promoter sequence must be present RNA strand must be present RNA polymerase must be present none of above

B. terminated by a protein called rho

In prokaryotes, transcription is A. terminated by the stop codon B. terminated by a protein called rho C. terminated by a poly A sequence D. terminated by a start codon

RNA polymerase

In transcription, particular segment of DNA is copied to RNA by enzyme DNA polymerase RNA polymerase gyrase helicase

B. sigma factor

In vitro the bacterial RNA polymerase core enzyme complex is capable of interacting with and transcribing DNA but is not capable of positioning itself at the start of a gene before beginning transcription. To do this the polymerase must first bind to a protein known as: A. The holoenzyme B. sigma factor C. Promotor D. TFIID

C. Position 3 only

In which base position(s) of the mRNA codon could nonstandard wobble base pairs like G-U form? A. Position 1 only B. Position 2 only *C. Position 3 only D. Positions 2 and 3.

A) nucleus

In which cellular organelle do the three posttranscriptional modifications often seen in the maturation of mRNA in eukaryotes occur? A) nucleus B) cytoplasm C) mitochondrion D) lysosome E) Golgi

A. Replication

In which process of information transfer would you find at work helicases, topoisomerases, ligases and a primase? *A. Replication B. Transcription C. Translation D. Reverse transcription

P site All amino acids are added to the A site except for the Met-tRNA which is added to the P-site

Initiation of protein translation begins with the addition of initial Met-tRNA in to the ____________ on the small ribosomal subunit.

ethidium bromide

Intercalates in DNA

E) are believed to have originated from transposons

Interspersed repeated DNA units: A) are arranged intandem B) tend to be smaller than 10 base pairs long C) constitute less than 10 percent of the DNA of most multicellular organisms D) are identical to one another E) are believed to have originated from transposons

a) True Feedback: In eukaryotes, RNA polymerase II transcribes all messenger RNAs (mRNAs). RNA polymerase I and III transcribe non-coding RNAs including ribosomal RNA (rRNA) and transfer RNA (tRNA).

Is the following statement true or false? 'Eukaryotic mRNA is transcribed by RNA polymerase II.' a) True b) False

D. M phase

It is useful to think about gene expression in eukaryotic cells in relation of the cell cycle. In which phase of the cell cycle is gene expression almost completely shut down? A. G1 phase B. S phase C. G2 phase *D. M phase

Dimethyl sulfite

Methylation of guanine

A. at the 3' end just after a poly adenylation signal

Most transcripts of protein coding genes are cleaved A. at the 3' end just after a poly adenylation signal B. at the 3' end just before a poly adenylation signal C. at the 5' end immediately after a poly adenylation signal D. at the 5' end immediately before a poly adenylation signal

A. are transcribed by rRNA polymerase III and the 5S rRNA

Multiple copies of 5S genes, located at a chromosomal site distinct from the other rRNA genes A. are transcribed by rRNA polymerase III and the 5S rRNA B. are transcribed by rRNA polymerase II C. are transcribed by rRNA polymerase I and the 5S rRNA D. are transcribed by DNA polymerase I

B) Adenine changed into cytosine

Mutation that results in a new triplet code for a different amino acid, is called: A) missense mutation B) Nonsense mutation C) Silent mutation D) Natural mutation E) All of above

E) spontaneous mutations

Mutations that arise in nature, from no particular artificial agent, are called ________. A) chromosomal aberrations B) cosmic mutations C) induced mutations D) oblique mutations E) spontaneous mutations

C) spontaneous mutations

Mutations that arise in nature, from no particular artificial agent, are called ________. A) natural mutations B) induced mutations C) spontaneous mutations D) chromosomal aberrations E) cosmic mutations

c) 2 Explanation: According to Watson-Crick base pair interactions, number of hydrogen bonds between U and A are 2 and between G and C are 3.

Number of hydrogen bonds that form between U and A in a Watson-Crick base pair interactions? a) 0 b) 1 c) 2 d) 3

C) 64, 61, 3

Of the ____ different possible codons, ____ specify amino acids and ____ signal stop. A) 20, 17, 3 B) 180, 20, 60 C) 64, 61, 3 D) 61, 60, 1

Some amino acids can be coded for by more than just one codon Explanation: While some of these answer choices are true, others are false. But even for the choices that are true, only one of them directly answers the question. Let's go ahead and look at each choice. Some amino acids can be coded for by more than just one codon This is a true statement, and is also the correct answer. The degeneracy of the code is due to the fact that, for some amino acids, a number of different codons can result in the same amino acid. For example, the amino acid tyrosine can be coded for by either UAU or by UAC. A change in the reading frame alters expression of all subsequent codons While this is a true statement, it does not answer the question. Nonetheless, it's important to know that mutations which either insert or delete a nucleotide will change the entire rest of the reading frame. Consequently, there are likely to be many errors and the resultant polypeptide will likely not be functional. Some codons are able to code for more than just one amino acid This is a false statement. But be careful. This answer choice looks a lot like the correct one. The difference is that, for this choice, we're talking about a single codon being able to code for more than one amino acid. This is not the case. The sequence of one type of molecule is able to code for the sequence of another type of molecule This is a true statement with regards to gene expression. For transcription, the DNA (sequence of deoxyribonucleotides) serves as a template for the formation of mRNA (sequence of ribonucleotides). And for translation, that same mRNA serves as a precursor for the formation of a polypeptide (sequence of amino acids). The same genetic code is not shared by all species From what we know, this is a false statement. The genetic code is universal, meaning that all living things have been found to have the same codon-amino acid relationship.

Oftentimes, biochemists say that the genetic code is degenerate. What are they referring to when they say this? Some amino acids can be coded for by more than just one codon Some codons are able to code for more than just one amino acid The same genetic code is not shared by all species The sequence of one type of molecule is able to code for the sequence of another type of molecule A change in the reading frame alters expression of all subsequent codons

c) lagging strand of newly synthesized DNA

Okazaki fragments make up part of the _____. a) small ribosomal subunit b) tRNA c) lagging strand of newly synthesized DNA d) mRNA

B) is the study of the collection of proteins produced in a particular cell.

Proteomics A) is another term for genomics in humans. B) is the study of the collection of proteins produced in a particular cell. C) is the study of proteins produced by a particular gene. D) proves that a single gene codes for only one protein.

B. RNA

RHO-dependent transcriptional termination requires binding of RHO to... A. DNA B. RNA C. Transcriptional factors D. Sigma factor

C. transcription, RNA polymerase

RNA is synthesized on a DNA template in a process called __________ , which utilizes the enzyme __________ A. translation, RNA polymerase B. transcription, DNA polymerase C. transcription, RNA polymerase D. replication, DNA polymerase

recognition of the -10 sequence and -35 sequence

RNA polymerase holoenzyme initiates transcription which involves A. recognition of the -10 sequence and -35 sequence B. recognition of the -10 sequence only C. recognition of the -35 sequence only D. none of the above

D. sigma subunit

RNA polymerase in prokaryotes has a removable A. alpha subunit B. beta subunit C. both (a) and (b) D. sigma subunit

Answer: DNA polymerase I Explanation: DNA polymerase I removes RNA primer from Okazaki fragment.

RNA primer is removed from the Okazaki fragment by a) DNA polymerase I b) DNA polymerase II c) DNA polymerase III d) RNA polymerase

It is found in viruses.

RNA replicase synthesizes RNA from an RNA template. RNA replicase differs from RNA polymerase in that: A. It requires ATP. B. It is found in viruses. C. It has proofreading capability. D. The synthesis of RNA proceeds in the 3'-5' direction.

5-bromouracil

Replaces thymine

Answer: Operator Explanation: A repressor molecule binds to operator.

Repressors bind to a) Promoter b) Enhancer c) Operator d) Hormone response element

D. I, II, and III Endonucleases are enzymes that cut DNA. They are used by the cell for DNA repair. They are also used by scientists during DNA analysis, as restriction enzymes are endonucleases. Restriction enzymes are used to cleave DNA before electrophoresis and Southern blotting, and to introduce a gene of interest into a viral vector for gene therapy.

Restriction endonucleases are used for which of the following? I. Gene therapy II. Southern blotting III. DNA repair

They contain arginine and lysine residues.

Single-stranded binding proteins (SSB) bind to the outer backbone of DNA during replication. What would you predict about SSBs? A. Sequence-specific binding B. They hydrolyze phosphodiester bonds. C. They contain arginine and lysine residues. D. They form covalent bonds to sugars.

All of these Explanation: The reverse transcriptase activity of retroviruses like HIV is used to replicate their RNA genome in the host cell. This activity is not needed or present in DNA viruses which can use the host's enzymes to replicate. The reverse transcriptase activity of telomerases is used to prevent telomere ends shortening after multiple replications in somatic cells. Telomeres are short sequences at the end of chromosomes that prevent deterioration of the chromosomes. Retrotransposones are elements that amplify repetitive sequences in the DNA of eukaryotes.

Reverse transcriptase is an enzyme that produces DNA molecules from RNA. Which of the following is correct? Retroviruses have this enzyme and use it to replicate their RNA genome All of these Reverse transcriptase activity is present in DNA viruses Telomerase (the enzyme that maintains telomere length in eukaryotes) has reverse transcriptase activity In eukaryotes reverse transcriptase is encoded by retrotransposons

a) RNA is used as a template to produce DNA

Reverse transcription occurs when: a) RNA is used as a template to produce DNA b) DNA is used as a template to produce RNA c) Protein is used as a template to produce RNA d) RNA is used as a template to produce protein

C. both (a) and (b)

Rho-dependent termination of transcription in E. coli A. requires ATP B. requires about 50 nucleotides of uncomplexed mRNA C. both (a) and (b) D. removes mRNA and holoenzyme from the DNA

Answer: b Explanation: Sigma factor enables specific binding of RNA polymerase to promoter.

Role of sigma factor in bacterial RNA polymerase is a) Catalyzing RNA synthesis b) Positioning RNA polymerase correctly on the DNA template c) Terminating RNA synthesis d) Unwinding DNA template

are called introns

Segments of eukaryotic DNA that do not code for proteins: a) are called introns b) are found in all bacterial genes c) can be considered by your immune system as enemy DNA d) binds to proteins to form ribosomes

D. General transcription factors

Sigma factor in bacteria is replaced in eukaryotes by A. RNA Polymerase I B. The C-terminal domain of RNA Polymerase II C. RNA Polymerase III D. General transcription factors

A) manufacture of synthetic RNA for cell-free systems

Significant in the deciphering of the genetic code was the discovery of the enzyme polynucleotide phosphorylase. What is this enzyme used for? A) manufacture of synthetic RNA for cell-free systems B) ribosomal translocation C) peptide bond formation D) production of ribosomal proteins E) degradation of RNA

e. All of the above are true.

Telomerase _____. a. contains its own RNA template b. is a reverse transcriptase c. extends one strand of the telomere d. is responsible for helping to maintain chromosome size e. All of the above are true.

B) eukaryotes than in prokaryotes

That some organisms contain much larger amounts of DNA than are apparently "needed" and that some relatively closely related organisms may have vastly different amounts of DNA is more typical in ________. A) RNA viruses than in DNA viruses B) eukaryotes than in prokaryotes C) the alphoid rather than the diploid family D) viruses than in bacteria E) prokaryotes than in eukaryotes

D. The DNA strand and the RNA strand can form a strong double helix , but they are separated when they exit the RNA polymerase

The RNA polymerase uses DNA as a template to synthesize RNA through base pairing but the resulting RNA stand do not stay with the DNA template to form a double helix . How is the RNA product displaced from its DNA template? A. The DNA template and the new RNA template strand are not antiparallel B. The DNA template and the new RNA template strand are antiparallel but because of their different chemical structure they cannot form a double helix C. DNA AND RNA form a double helix but the base pairing between RNA and DNA is much weaker than DNA: DNA double helix D. The DNA strand and the RNA strand can form a strong double helix , but they are separated when they exit the RNA polymerase

A. multisubunit enzymes

The RNA polymerases that transcribe bacterial DNA are A. multisubunit enzymes B. only active inside the cell C. interchangable with DNA polymerases D. highly glycosylated in their active forms

are removed by Pol I "nick translation".

The RNA primers used to initiate replication in E. coli result in Okazaki fragments on the leading strand. are removed by Pol I "nick translation". are joined together by DNA ligase. are removed by helicase + ATP. The first and second choices are both correct.

B. It remains bound to the promoter

The TATA box-binding protein TBP and TAFs constitute the general transcription factor TFIID. What happens to the TFIID after the polymerase escapes from the promoter. A. It moves with the polymerase B. It remains bound to the promoter C. It is released from the promoter into the solution to initiate another round of transcription D. Any of the above since it is no longer needed

A. competitive inhibition of an enzyme

The binding of lac repressor to DNA could be considered to be analogous to A. competitive inhibition of an enzyme B. mixed-type inhibition of an enzyme C. uncompetitive inhibition of an enzyme D. allosteric effects in enzyme regulation

in equilibrium with free RNA polymerase and the promoter

The closed complex at bacterial promoters is A. in equilibrium with free RNA polymerase and the promoter B. not affected by promoter mutations C. bound more tightly when repressors are present D. not affected by activator proteins

transcription bubble

The complex of RNA polymerase, DNA template and new RNA transcript is called A. transcription bubble B. replication bubble C. a translation bubble D. none of these

one has a 5'-3' exonuclease activity, the other does not.

The differences between Pol I and Pol III are: one is an RNA polymerase, the other is a DNA polymerase. one has a 3'-5' exonuclease activity, the other does not. one has a 5'-3' exonuclease activity, the other does not. one utilizes RNA primers, the other does not. Pol I and Pol III are different names that describe the same enzyme.

Transfer Amino Acids to Ribosomes

The function of tRNA, is to: • Synthesize DNA • Synthesize mRNA • form Ribosomes • Transfer Amino Acids to Ribosomes

A. assure that transcription begins at the proper point

The function of the sigma factor of RNA polymerase is to A. assure that transcription begins at the proper point B. assure that transcription ends at the proper point C. assure that translation begins at the proper point D. assure that translation ends at the proper point

Many of the amino acids have more than one triplet codon There are 64 codons but only 20 amino acids.

The genetic code is said to be degenerate because of which of the following? Many of the amino acids have more than one triplet codon All triplets have at least one uracil. Some triplets are made up of repeating purines or pyrimidines. Many codons have pairs of identical bases next to each other.

B) are three bases in mRNA that code for an amino acid

The genetic code is said to be triplet, meaning that there ________. A) are three amino acids per base in mRNA B) are three bases in mRNA that code for an amino acid C) may be three ways in which an amino acid may terminate a chain D) are three "nonsense" triplets E) None of the answers listed is correct.

A) are three bases in mRNA that code for an amino acid

The genetic code is said to be triplet, meaning that there ________. A) are three bases in mRNA that code for an amino acid B) are three amino acids per base in mRNA C) may be three ways in which an amino acid may terminate a chain D) are three "nonsense" triplets E) none of the above

a) The leading strand is synthesized in the same direction as the opening of the replication fork, and the lagging strand is synthesized in the opposite direction

The leading and the lagging strands differ in that a) The leading strand is synthesized in the same direction as the opening of the replication fork, and the lagging strand is synthesized in the opposite direction b) The leading strand is synthesized by adding nucleotides to the 3' end of the growing strand, and the lagging strand is synthesized by adding nucleotides to the 5' end c) The lagging strand is synthesized continuously, whereas the leading strand is synthesized in short fragments that are ultimately stitched together d) None of the above are true

B. recognition of the transcriptional start sequence

The major function of RNA polymerase's sigma factor is A. recognition of the translational stop sequence B. recognition of the transcriptional start sequence C. recognition of the transcriptional stop sequence D. recognition of the translational start sequence

DNA ligase.

The nicks, or gaps, between fragments on the lagging strand are eventually sealed by Crazy glue. DNA ligase. RNA ligase. Restriction endonucleases. Gyrase.

E) All of the above are correct.

The poly(A) tail of mRNAs _____. A) is added to the 3' end of mRNAs B) is found on most mature eukaryotic mRNAs C) is added after transcription D) helps prevent degradation of eukaryotic mRNAs E) All of the above are correct.

b) False Feedback: There is no coding sequence for polyA. The polyA tail is added on to the mRNA after transcription. After transcription, the transcript is cleaved near to the polyadenylation signal, AAUAAA, and as many as 200 adenine nucleotides are added, using ATP as the source of these adenines.

The polyA tail on eukaryotic mRNA is encoded by a long string of Ts at the end of the gene. Is this statement true or false? a) True b) False

two transesterifications Explanation: The spliceosome first releases the 5' exon by forming a lariat structure (2'-5' phosphodiester) bond between two introns in a transesterification reaction. Then, the exons are spliced together with another transesterifaction reaction, and the intron lariat is released.

The post-transcriptional spliceosome reaction, which removes the intron in a lariat structure, takes place via _______ one transesterification and one transacetylation two isomerizations two transesterifications one transacetylation two transacetylations

c) translation

The process of ________ results in the synthesis of a new protein. a) replication b) transcription c) translation d) transversion

protein synthesis

The process of transferring a gene's instructions for making a protein is translation • replication • transcription • protein synthesis • all of the above

B) mRNAs are made from genes

The relationship between a gene and a messenger RNA is that ________. A) genes are made from mRNAs B) mRNAs are made from genes C) mRNAs make proteins, which then code for genes D) all genes are made from mRNAs E) mRNA is directly responsible for making Okazaki fragments

C) tRNA

The role of ______ is to carry amino acids to the ribosomes. A) DNA B) mRNA C) tRNA D) rRNA E) protein

A) charge tRNA with amino acid

The role of aminoaccyl tRNA synthetase is A) charge tRNA with amino acid B) catalyzes the peptide bond formation between amino acids C) translocate peptide to the ER compartment D) recruit the GTP-dependent release factor E) Transfer charged tRNA molecule to the ribosome

to position RNA polymerase correctly on the template DNA. Feedback: RNA polymerase of E. coli is a large complex of several protein subunits. The 'core' enzyme (two copies of an α subunit, two related subunits termed β and β', and an ω subunit) has an affinity for DNA, can unwind the DNA template, and can even catalyse RNA synthesis from the template strand, but it cannot recognize the correct initiation site until it is joined by another protein from the cytosol, the sigma subunit (σ) or sigma factor. With this attached, the polymerase binds to the -35 and Pribnow boxes and initiation of transcription can start.

The role of the sigma factor in bacterial RNA polymerase is: a) to catalyse RNA synthesis: b) to position RNA polymerase correctly on the template DNA. c) to terminate RNA synthesis. d) to unwind the DNA template.

C) α-helix and β-pleated sheet

The secondary structure of a protein includes ________. A) gamma and delta B) alpha and gamma C) α-helix and β-pleated sheet D) hydrophobic clusters E) disulfide bridges

RNA polymerases can begin a new RNA chain with the addition of the first nucleoside triphosphate but not DNA polymerase which requires a primer sequence.

The synthesis of RNA and DNA have a number of features in common but there is one big difference. Choose the answer that gives a property of RNA synthesis that is not shared by DNA synthesis: A. Synthesis proceeds in the 5' to 3' direction. B. Synthesis requires a cellular supply of nucleoside triphosphates. C. New chains are produced using an exisiting or parental strand as a template. *D. RNA polymerases can begin a new RNA chain with the addition of the first nucleoside triphosphate but not DNA polymerase which requires a primer sequence.

C)RNA polymerase.

The transcribing enzyme is A)ligase. B)DNA polymerase. C)RNA polymerase. D)amino-acyl transferase.

Six general transcription factors Explanation: The correct answer is "six general transcription factors." RNA polymerase I is used to transcribe rRNAs, not mRNAs. The rho factor is used to initiate transcription in prokaryotes, not eukaryotes. Elongator is a factor used by eukaryotes to elongate transcripts and speed up transcription, but is not required to initiate transcription.

The transcription of mRNAs in eukaryotes requires ___________ to initiate transcription. Possible Answers: Elongator Rho factor Six general transcription factors RNA polymerase I

A. at least two distinct domains of protein structure, a DNA binding domain and an activation domain

The transcriptional regulatory proteins in eukaryotes which induce transcription usually have A. at least two distinct domains of protein structure, a DNA binding domain and an activation domain B. at least two distinct domains of protein structure and a DNA binding domain C. at least one distinct domains of protein structure, a DNA binding domain and an activation domain D. none of these

occur at two different active sites.

The two exonuclease activities of DNA polymerase I occur at two different active sites. are coupled during the formation of "gapped DNA". degrade DNA in a 5' --> 3' direction. degrade DNA in a 3' --> 5' direction. are not essential for viability of E. coli.

C) There are 61 different codons that code for the 20 major amino acids

The wobble hypothesis accounts for the fact that: A) There are 3 different codons for stop signal B) There are 64 different codons that code for the 20 major amino acids C) There are 61 different codons that code for the 20 major amino acids D) There are 64 different codons that can base-pair with the codons that specify all 20 amino acids E) All of the above A) TATA

UV light unit

Thymine-dimer formation

A. Alpha

To study the 5' capping process you want to radiolabel the G to be added to the 5' end of an mRNA. Which phosphate would you radiolabel? A. Alpha B. Beta C. Gamma D. Doesn't matter

A) 10

Transcription and translation of a gene composed of 30 nucleotides would form a protein containing no more than ___ amino acids. A) 10 B) 15 C) 60 D) 90

B. upstream from the start codon

Transcription begins A. at the start codon B. upstream from the start codon C. downstream from the start codon D. none of these

B. three phases known as initiation, elongation and termination

Transcription by E. coli polymerase occurs in A. four phases known as initiation, propagation, elongation and termination B. three phases known as initiation, elongation and termination C. two phases known as initiation and termination D. none of the above

B. proteins which bind to DNA and regulate transcription

Transcription factors are A. promoters B. proteins which bind to DNA and regulate transcription C. TATA boxes D. CATT boxes

Answer: DNA-dependent RNA polymerases Explanation: Transcription is catalyzed by DNA-dependent RNA polymerases, which use ribonucleotide 5'-triphosphates to synthesize RNA complementary to the template strand of duplex DNA.

Transcription is catalyzed by a) DNA-dependent RNA polymerases b) RNA-dependent DNA polymerases c) Reverse transcriptases d) DNA ligases

3' to 5'; 5' to 3

Transcription occurs along a ____ template forming an mRNA in the ____ direction. A) 5' to 3'; 5' to 3' B) 5' to 3'; 3' to 5' C) 3' to 5'; 5' to 3' D) 3' to 5'; 3' to 5'

A. a single 45S rRNA precursor molecule

Transcription of each set of rRNA genes by RNA polymerasel produces A. a single 45S rRNA precursor molecule B. a single 5S rRNA precursor molecule C. a single 18S rRNA precursor molecule D. a single 28S rRNA precursor molecule

B) anticodon.

Transfer RNA's bind during translation by the A) codon. B) anticodon. C) template.

A. loss of function mutations.

Tumor suppressor genes are most likely to result in cancer through: A. loss of function mutations. B. gain of function mutations. C. overexpression. D. proto-oncogene formation.

C) transversions and transitions

Two formal terms used to describe categories of mutational nucleotide substitutions in DNA are ________. A) base analogs and frameshift B) error prone and spontaneous C) transversions and transitions D) euchromatic and heterochromatic E) sense and antisense

C. promoters

Upstream regions which are essential for correct transcription are called A. enhancers B. start codons C. promoters D. transcription factors

B. A specific sequence of DNA to which RNA polymerase binds

What is a promoter? A. A specific sequence of DNA to which a catabolic repressor binds B. A specific sequence of DNA to which RNA polymerase binds C. A specific DNA sequence to which a restriction endonuclease binds D. None of the above

Trinucleotide CCA

What is added to the 3′-end of many eukaryotic tRNAs after transcription and is required for the ability of the tRNA to carry amino acids?

C. they are both AT- rich

What is common between the proximal promoter regions in prokaryotes and eukaryotes? A. they are bound by the same protein B. they are both GC rich C. they are both AT- rich D. they are located the same distance (10 bp) from the transcriptional start site

B. hydroxyl bond

What is the common structural element or feature that is phosphorylated? A. hydrogen bond B. hydroxyl bond C. negative charge D. Positive charge

The TATA box is a binding site that helps recruit RNA polymerase molecules and is found in the promoter

What is the function of the TATA box and where is it found?

C) AUG; methionine

What is the initiator triplet in both prokaryotes and eukaryotes? What amino acid is recruited by this triplet? A) UAA, methionine B) AUG; arginine C) AUG; methionine D) UAA; no amino acid called in E) UAA or UGA; arginine

D) AUG; methionine

What is the initiator triplet in both prokaryotes and eukaryotes? What amino acid is recruited by this triplet? A) UAA; no amino acid called in B) UAA or UGA; arginine C) AUG; arginine D) AUG; methionine E) UAA, methionine

Minus-strand RNA Explanation: We're given the type of enzyme contained within a virus, and we're asked to make a determination of the virus' genetic makeup. To begin with, we're told that the enzyme is an RNA-dependent RNA polymerase. The name of the enzyme gives us insight into what it does. It requires RNA as a template to produce more RNA. So if this enzyme can convert RNA into RNA, where does the original RNA come from? The answer is that it must come from the virus. This means that we must be dealing with single-stranded RNA. Now, the question is to determine the sense of the RNA genome of the virus. That is to say, it can be minus or plus. A minus-sense RNA is one whose complementary sequence can be translated into protein. A plus-sense RNA is one that doesn't need any processing to be translated. Rather, plus-sense RNA can be translated right away. Since we know that the enzyme present is going to produce RNA from RNA, we can then reason that the viral genome is likely minus-sense. When the minus-sense RNA is enacted on by this enzyme, the result is a new strand of RNA that can be translated into protein to serve the needs of the virus.

What is the likely genetic make-up of a virus which contains a RNA-dependent RNA polymerase? Possible Answers: Plus-strand RNA Double-stranded RNA Minus-strand RNA Single-stranded DNA Double-stranded DNA

B. Pol II needs a template, while PAP does not

What is the major difference between polyA polymerase (PAP) and RNA polymerase II? A. One synthesizes DNA and the other synthesizes RNA B. Pol II needs a template, while PAP does not C. Pol II does not know when to stop. PAP does D. They elongate different RNA molecules

E) codon

What is the name given to the three bases in a messenger RNA that bind to the anticodon of tRNA to specify an amino acid placement in a protein? A) protein B) anti-anticodon C) cistron D) rho E) codon

Reverse transcription Explanation: For biochemical purposes, it is important to have an understanding of the "Central Dogma" of molecular biology. DNA multiplies via replication, is turned into RNA via transcription, and finally to proteins via translation. Going back to DNA from RNA is known as reverse transcription, and is the correct answer. The term "reverse translation" can refer to an aspect of cloning, but does not naturally occur.

What is the name of the process in which RNA is converted to DNA? Possible Answers: Reverse transcription Replication Translation Transcription Reverse translation

I, II, and IV Explanation: The RNA transcript contains nucleotide bases at each position, which are complementary to the DNA. RNA is synthesized in the 5' to 3' direction from a DNA template strand with antiparallel direction (3' to 5').The coding DNA strand is identical to the RNA transcript with the exception that thymine is replaced with uracil in RNA.

What is the relationship of the RNA transcript to the DNA template strand? I. The RNA transcript is antiparallel to the DNA template strand. II. The RNA transcript is complementary to the DNA template strand. III. The RNA transcript is identical to the DNA template strand. IV. In the RNA transcript, thymine is replaced with uracil.

d) Transcription of the major rRNA transcript. Feedback: The basic enzymic reaction by which RNA is synthesized in eukaryotes is the same as in prokaryotes. However, in eukaryotes there are three different RNA polymerases, designated I, II, and III, which are responsible for transcribing different classes of gene. RNA polymerase I (Pol I) transcribes the major rRNA transcript. RNA polymerase II (Pol II) transcribes mRNA. RNA polymerase III (Pol III) transcribes 'small' RNAs: tRNAs, 5S rRNA and small nuclear RNAs (snRNAs), a class of nonprotein-coding RNA molecules with varied functions such as RNA splicing.

What is the role of eukaryotic RNA polymerase I? a) Transcription of mRNA only. b) Transcription of mRNA, rRNA and tRNA. c) Transcription of 'small' RNAs including tRNAs, 5S RNAs and snRNAs. d) Transcription of the major rRNA transcript.

and II Explanation: Termination of transcription in prokaryotes (intrinsic termination) is mediated by special DNA secondary structures (stem and loop structures). Stem and loop structures have nucleotides that are complementary with the adjacent nucleotides. Along with a poly uracil sequence, these structures do not allow transcription to go further.In rho-dependent termination, rho binds to RNA until it reaches a RNA-DNA helical region, where it acts as a helicase and unwinds the complex. This in turn stops transcription. Sigma and TFIID are important in transcription in eukaryotes, not prokaryotes.

What is the signal for termination of transcription in prokaryotes? I. The rho factor II. Stem and loop RNA structures and a poly uracil sequence III. The sigma factor IV. Transcription factor TFIID

The template for transcription can be found on either strand of DNA Explanation: The saying that genes can run in either direction is referring to how they can be expressed. Genes can be found on either strand of the DNA molecule. Since these two strands run antiparallel to one another, the genes being read on one strand would be read in the opposite direction on the other strand. Genes can also be located on various loci within a given chromosome. Also, it is true that genes assort independently during cell division, but this doesn't answer the question. Also, genes can only be read in the 5′→3′ direction. They can never be read in the 3′→5′ direction. This is because DNA polymerase, the enzyme responsible for elongating the chain, can only add nucleotides to a chain that has a hydroxyl group at the 3′ position

When biochemists says that genes can be in either direction of the DNA, what do they mean? Genes can be found both in the middle and at ends of a chromosome Genes can be transcribed in both directions, from 5′→3′ and 3′→5′ The different alleles for a given gene within chromosomes can be partitioned to either of two cells during mitosis The template for transcription can be found on either strand of DNA

A) TATA

When considering the initiation of transcription in eukaryotes, one often finds consensus sequences located in the region of the DNA where RNA polymerase(s) binds. Which of the following is a common consensus sequence? A) TATA B) GGTTC C) TTTTAAAA D) any trinucleotide repeat E) satellite DNAs

C) there can be more than one codon for a particular amino acid

When examining the genetic code, it is apparent that ________. A) there can be more than one amino acid for a particular codon B) AUG is a terminating codon C) there can be more than one codon for a particular amino acid D) the code is ambiguous in that the same codon can code for two or more amino acids E) there are 44 stop codons because there are only 20 amino acids

C) there can be more than one codon for a particular amino acid

When examining the genetic code, it is apparent that ________. A) there can be more than one amino acid for a particular codon B) there are 44 stop codons because there are only 20 amino acids C) there can be more than one codon for a particular amino acid D) the code is ambiguous in that the same codon can code for two or more amino acids E) AUG is a terminating codon

B) many amino acids have more than one codon.

When scientists describe the genetic code as redundant, they mean that: A) it becomes disorganized over time. B) many amino acids have more than one codon. C) some codons specify stop signals. D) it varies with cell type. E) it varies among species

Answer: Promoter Explanation: Transcription initiation occurs when RNA polymerase binds at specific DNA sequences called promoters.

Where does RNA polymerase bind DNA? a) Promoter b) Operator c) Enhancer d) None

mRNA

Which Type of RNA Functions as a blueprint for DNA? rRNA • tRNA • mRNA • DNA Polymerase

A. Initial melting of DNA

Which component of transcription in bacteria requires no energy from hydrolyzing ATP (or CTP, GTP, UTP) A. Initial melting of DNA B. Abortive initiation C. Elongation D. Rho- dependent termination

Reverse transcriptase Explanation: The "central dogma" of biology says that information goes from DNA via transcription to RNA via translation to proteins. Reverse transcriptases, however, employed by retroviruses, synthesize DNA from RNA. As for the other enzymes: one function of helicases (among others) is to pull apart double helix strands. Catalase breaks down hydrogen peroxide. Carboxylase adds a carboxyl group to a substrate, and a ligase creates a bond between two molecules, for example, via a phosphodiester bond.

Which enzyme could be considered to violate the "central dogma" of biology? Catalase Ligase Carboxylase Helicase Reverse transcriptase Correct answer:

B. RNA Pol II

Which enzyme transcribes the most number of genes A. RNA Pol I B. RNA Pol II C. RNA Pol III D. They divide the number of genes more or less equally

C) DNA to protein

Which mode of information transfer usually does not occur? A) DNA to DNA B) DNA to RNA C) DNA to protein D) all occur in a working cell

B) mRNA

Which molecule contains the genetic code? A) DNA B) mRNA C) tRNA D) rRNA

A) Photoreactivation repair

Which of the following DNA repair mechanism is not found in human? A) Photoreactivation repair B) Base excision repair C) Nucleotide excision repair D) Homologous recombination repair E) Double strand break repair

B) A free phosphate group at the 5' end of a strand

Which of the following are NOT required for DNA replication? A) A free hydroxyl group at the 3' end of a strand B) A free phosphate group at the 5' end of a strand C) Nucleotide triphosphates D) DNA polymerase III E) RNA primase

I. The product has more uracil than the parent strand Explanation: Transcription is the second process involved in the production of proteins from a gene. The three processes are DNA replication, transcription, and translation. DNA replication involves replication of DNA from a parent strand, transcription involves the synthesis of a RNA molecule from a DNA molecule, and translation involves the conversion of the mRNA molecule to a polypeptide. As mentioned, transcription produces an RNA molecule from a DNA molecule (parent strand). Recall that RNA molecules have uracil, whereas DNA molecules have thymine; therefore, the product will contain more uracil. Amino acids are found in proteins. Since the products of transcription are nucleic acids (RNA molecules) they won't contain any amino acids. Recall that a nucleic acid consists of pentose sugar molecules (ribose in RNA and deoxyribose in DNA), nitrogenous bases (adenine, guanine, cytosine, thymine (in DNA), and uracil (in RNA)), and phosphate groups. RNA polymerase is an important enzyme involved in transcription. Its function is to add nucleotides to the growing mRNA chain. Although it adds complementary nucleotides to the DNA, RNA polymerase itself doesn't bind to complementary DNA sequences, rather it binds at promoters.

Which of the following are true regarding the product of transcription? I. The product has more uracil than the parent strand II. The product has both hydrophilic and hydrophobic amino acids III. The nucleotides on the RNA polymerase binds to complementary nucleotides on the parent strand

b) A modified guanine nucleotide added to the 5' end of the transcript. Feedback: The RNA of the eukaryotic gene primary transcript immediately undergoes a modification at its 5' end, called capping. At the 5' end of the primary RNA transcript there is a triphosphate group because the first nucleotide triphosphate simply accepts a nucleotide on its 3'-OH. The terminal phosphate of this is removed and a GMP residue is added from GTP (Fig. 24.11). The 5'-5' triphosphate linkage is unusual. The G is then methylated in the N-7 position as is also the 2'-OH of the second nucleotide. The cap protects the end of the mRNA from exonuclease attack and it is involved in initiation of translation as described in the next chapter. Termination of transcription in eukaryotic cells is less understood than the prokaryotic mechanism. Most, though not all, eukaryotic mRNAs end in a string of up to 250 adenine residues known as a 3' polyA tail. The polyA tail is not directly encoded by the gene, but its position is directed by a polyadenylation signal (AAUAAA) that is encoded by the gene and transcribed in the primary transcript. Page reference: 381-382, 384

Which of the following best describes the 'cap' modification of eukaryotic mRNA? a) A modified guanine nucleotide added to the 3' end of the transcript. b) A modified guanine nucleotide added to the 5' end of the transcript. c) A string of adenine nucleotides added to the 3' end of the transcript. d) A string of adenine nucleotides added to the 5' end of the transcript.

D) Ethidium bromide

Which of the following can result in frameshift mutations? A) Alkylating agent B) Tautomeric shift C) Base analog D) Ethidium bromide E) Deamination

a. Acetylation of histones

Which of the following chemical modifications is associated with increased gene activity? a. Acetylation of histones b. Methylation of DNA c. Demethylation of histones d. Phosphorylation of histones e. Phosphorylation of DNA

tRNA (transfer RNA) tRNA maturation occurs thru folding into a clover formation and the addition of the amino acid attachment site. See figure 14.20

Which of the following classes of RNA characteristically contains modified or unusual purines and pyrimidines?

D. Both (b) and (c)

Which of the following conditions would cause the release of the lac repressor protein from the lac operator site on DNA? A. Presence of glucose in the growth media B. Presence of lactose in the growth media C. Presence of IPTG (isopropyl thiogalactoside) in the growth media D. Both (b) and (c)

A) 5'-capping, 3'-poly(A) tail addition, splicing

Which of the following contains the three posttranscriptional modifications often seen in the maturation of mRNA in eukaryotes? A) 5'-capping, 3'-poly(A) tail addition, splicing B) 3'-capping, 5'-poly(A) tail addition, splicing C) removal of exons, insertion of introns, capping D) 5'-poly(A) tail addition, insertion of introns, capping E) heteroduplex formation, base modification, capping

E) 5′-capping, 3′-poly(A) tail addition, splicing

Which of the following contains the three posttranscriptional modifications often seen in the maturation of mRNA in eukaryotes? A) heteroduplex formation, base modification, capping B) removal of exons, insertion of introns, capping C) 3′-capping, 5′-poly(A) tail addition, splicing D) 5′-poly(A) tail addition, insertion of introns, capping E) 5′-capping, 3′-poly(A) tail addition, splicing

TATA-box binding protein Feedback: TBP is a protein that attaches the transcription factor TFIID to the TATA box, in eukaryotes, and its full name is 'TATA-box binding protein'.

Which of the following does the abbreviation TBP stand for? a) TATA-box binding protein b) Transcription associated factor c) Transcription factor binding protein d) TATA box polymerase

A. Reverse trancription

Which of the following enzymes is not involved in DNA replication A. Reverse trancription B Helicase C Primase D. topo isomerase E. DNA polymerase

C) the forming of peptide bonds

Which of the following events is NOT involved in mRNA processing? A) the addition of a 5′ "cap" B) the addition of a poly-A tail C) the forming of peptide bonds D) the splicing together of exons E) the removal of introns

A. 5' capping of the mRNA

Which of the following events occurs before the transcription of the polyA signal (not the poly A tail) into mRNA? A. 5' capping of the mRNA B. Cleavage of the mRNA releasing it from the RNA polymerase C. Addition of many adenine residues to the 3' end of the mRNA D. Degradation of the mRNA remaining associated with RNA polymerase by a 5' to 3' ribonuclease

D) mRNA transcripts are extensively modified before they leave the nucleus.

Which of the following events occurs in eukaryotic cells but NOT in prokaryotic cells? A) RNA polymerase attaches to a particular nucleotide sequence on the DNA. B) RNA is synthesized using the 3′ to 5′ DNA strand as a template. C) Two or more structural genes are transcribed onto a single RNA molecule. D) mRNA transcripts are extensively modified before they leave the nucleus. E) tRNAs, rRNAs, and mRNAs are all involved in the translation process.

Deoxyribose+Phosphate+Cytosine

Which of the following is a nucleotide Unit found in DNA • Ribose+phosphate+Thymine • Deoxyribose+Phosphate+Uracil • Deoxyribose+Phosphate+Cytosine • Ribose+phosphate+Uracil

Deoxyribose+Phosphate+Cytosine

Which of the following is a nucleotide unit that would be found in DNA Ribose+phosphate+Thymine • Deoxyribose+Phosphate+Uracil • Deoxyribose+Phosphate+Cytosine • Ribose+phosphate+Uracil

RNase P RNase H is involved in reverse transcriptase, but it is not a ribozyme. RNase P is a ribonuclease that cleaves/processes rRNA and generates 5' ends. The RNA component of RNase P is its catalytic subunit.

Which of the following is a ribozyme? All of these are ribozymes RNA polymerase II RNase H RNase P Guanyltransferase

A) a given amino acid has more than one codon

Which of the following is an example of the degeneracy of the genetic code? A) a given amino acid has more than one codon B) each codon specifies more than one amino acid C) the first two bases specify the amino acid D) the genetic code is not degenerate

D. Both DNA & RNA polymerase

Which of the following is necessary for transcription to occur? A. DNA molecule B. RNA polymerase C. DNA polymerase D. Both DNA & RNA polymerase

Goldstein-Hogness (TATA) box

Which of the following is the eukaryotic equivalent of the prokaryotic Pribnow box ?

Answer: Synthesis of RNA is always in the 5' to 3' direction Explanation: Unlike DNA polymerase, RNA polymerase does not require a primer to initiate transcription.

Which of the following is true about RNA synthesis? a) Synthesis of RNA is always in the 5' to 3' direction b) RNA polymerase requires a primer for initiating transcription c) U is inserted opposite T in transcription d) New nucleotides are added on the 2'-OH of the ribose sugar

a) RNA synthesis is always in the 5' - 3' direction. Feedback: In transcription, as in DNA replication, nucleotides are added on to the 3' OH of the growing chain so RNA synthesis is always in the 5' - 3' direction. Unlike DNA synthesis, a primer is not needed for initiating a new strand. RNA contains U instead of T, and U base pairs with A and is inserted opposite A (not T) in the template.

Which of the following is true of RNA synthesis (transcription)? a) RNA synthesis is always in the 5' - 3' direction. b) RNA polymerase needs a primer to initiate transcription. c) In transcription, U is inserted opposite T. d) New nucleotides are added on to the 2' OH of the ribose sugar.

b) PCR utilises the separation of DNA strands at high temperature above the TM

Which of the following is true regarding PCR? a) Tm = temperature at which 90% of helical structure is lost b) PCR utilises the separation of DNA strands at high temperature above the TM c) G and C melts at a lower temperature d) The orientation of a primer contributes to the Tm of the primer

D) Introns may be involved in exon shuffling.

Which of the following statements is true regarding introns? A) Introns are the parts of mRNA that are translated. B) Introns have no function. C) In general, human genes have fewer introns than genes of other organisms. D) Introns may be involved in exon shuffling.

None of the these are true Prokaryotic and eukaryotic transcription are similar in many ways; however, they are also different from one another. One main difference is that in eukaryotic transcription there are several events that occur after the completion of transcription. These events are called post-transcriptional modifications. There are three main post-transcriptional modifications: polyadenylation, capping, and splicing. Polyadenylation involves the addition of multiple adenine molecules at the 3' end of the newly synthesized RNA molecule. This segment of RNA with multiple adenine molecules is called the poly A tail. Capping involves the addition of a methyl cap to the 5' end of the RNA molecule. Splicing involves the excision of segments of the mRNA molecule that aren't used in translation. These segments are called introns and the usable segments are called exons. The exons are ligated back together and the end product is released into the cytoplasm where it can undergo translation. Products of prokaryotic transcription don't undergo any of these post-transcriptional modifications and are immediately translated into proteins.

Which of the following is true regarding both prokaryotic and eukaryotic transcription? None of the these are true Both involve polyadenylation and addition of methyl cap at the 5' end Both involve polyadenylation and addition of methyl cap at the 3' end Polyadenylation and addition of methyl cap occurs only in prokaryotic transcription

The poly A tail is added to the 3' end of mRNA Explanation: After transcription, mRNA is modified so that it can be preserved for a longer time in the cell. A nucleotide cap structure is attached to the 5' end of the mRNA and a poly A tail is attached to the 3' end of the mRNA in order to accomplish this goal.

Which of the following matches is correct regarding eukaryotic termination of transcription? Possible Answers: The poly A tail is added to the 3' end of mRNA The mRNA cap and the Poly A tail are added to the 3' end of mRNA The mRNA cap and the poly A tail are added to the 5' end of mRNA The mRNA cap is added to the 3' end of mRNA The poly A tail is added to the 5' end of mRNA

C) tRNA

Which of the following molecules contains an anticodon? A) DNA B) mRNA C) tRNA D) rRNA E) protein

) Promoter. d) DNA-dependent RNA polymerase. Feedback: DNA-dependent RNA polymerases are the enzymes responsible for transcription in both eukaryotes and bacteria, and both have promoters for initiation of transcription. However, only eukaryotic messages are capped at the 5' end with methylated GMP, and only eukaryotic messages have a polyA tail (a string of up to 200 adenines that are added to the 3' end).

Which of the following occur in both eukaryotic and bacterial transcription? Please select all that apply. a) 5' cap. b) polyA tail. c) Promoter. d) DNA-dependent RNA polymerase.

E) There is only one origin of replication.

Which of the following statements about DNA replication in eukaryotes is FALSE? A) It is a bidirectional process. replication. B) DNA polymerases catalyze the synthesis of the new strands. C) DNA polymerases catalyze the synthesis of the new strands. D) The two replication forks move in opposite directions away from the origin. E) There is only one origin of replication.

) Self-splicing introns do not require the help of any protein for splicing to occur accurately. Feedback: Self-splicing introns do not require a spliceosome or any other proteins for the splicing reaction. Instead, the RNA transcript catalyses its own splicing reaction and is, therefore, an example of a 'ribozyme' (an RNA enzyme). Split genes have the advantage that they allow alternative splicing so that a single gene can code for variant forms of the same protein. These variant forms may have slightly different properties suited to different tissues. β-thalassaemia results from faulty splicing of the β-globin transcript. However, the spliceosome is normal and the reason for the fault is a mutation in the β-globin gene itself. Splicing occurs in the nucleus and mature transcripts are then transported into the cytosol for translation (protein synthesis) to occur.

Which of the following statements about mRNA splicing is true? a) The existence of split genes has no advantage b) Self-splicing introns do not require the help of any protein for splicing to occur accurately. c) β-thalassaemia results from a genetic defect in the spliceosome. d) Splicing occurs in the cytosol.

B) They consist of three nucleotides that bind to a codon.

Which of the following statements about promoters is FALSE? A) They are specific nucleotide sequences of DNA. B) They consist of three nucleotides that bind to a codon. C) They determine the position where RNA synthesis begins. D) They determine which DNA strand is used as a template. E) They are binding sites for RNA polymerase.

C) They are dispersed throughout the DNA

Which of the following statements about simple-sequence repeated DNA segments is FALSE? A) They are tandemly repeated B) The occur in telomeres C) They are dispersed throughout the DNA D) They occur in centromeres E) They have fewer than 10 base pairs

D) They are regions of active transcription.

Which of the following statements concerning telomeres is FALSE? A) They consist of simple-sequence repeated DNA. B) They are located at the ends of the chromosomes. C) They serve as caps. D) They are regions of active transcription. E) They protect the chromosome from degradation.

C. Telomerase adds a repeating sequence to the 5' end of DNA.

Which of the following statements is NOT true of telomerase? A. Telomerase contains a ribozyme. B. Telomerase activity decreases as the cell ages. C. Telomerase adds a repeating sequence to the 5' end of DNA. D. Telomerase adds a repeating sequence to the 3' end of DNA. E. Telomerase is found only in eukaryotes.

C) The corresponding amino acid is bound to the 5' end of tRNA

Which of the following statements is incorrect regarding tRNA? A) tRNA contains anticodon that base-pairs with codon in the mRNA. B) tRNA has a two-dimensional structure of cloverleaf. C) The corresponding amino acid is bound to the 5' end of tRNA. D) tRNA contains post-transcriptionally modified bases. E) tRNAs do not form into polymer chain

C) They are the most abundant type of repeat in the genome.

Which of the following statements is true regarding transposons? A) They are sequences of mRNA that can move around in the genome. B) They exist in corn, but are not found in the human genome. C) They are the most abundant type of repeat in the genome. D) All of the above are true regarding transposons.

DNA strands replicate in a 5′ to 3′ direction, whereas RNA is synthesized in a 3′ to 5′ direction.

Which of the following statements regarding differences between DNA and RNA is FALSE? A. DNA is double-stranded, whereas RNA is single-stranded. B. DNA uses the nitrogenous base thymine; RNA uses uracil. C. The sugar in DNA is deoxyribose; the sugar in RNA is ribose. D. DNA strands replicate in a 5′ to 3′ direction, whereas RNA is synthesized in a 3′ to 5′ direction.

b) Several reactions in the splicing process involve hydrolysis of ATP. Feedback: Splicing involves removal of the unwanted RNA introns of a primary transcript and joining up the exons into mRNA. The key to it is the transesterification reaction. In this, a phosphodiester bond is transferred to a different -OH group. There is no hydrolysis and no significant energy change during the bond rearrangements. In most cases, the splicing reaction in the nucleus is catalysed by very complex protein-RNA structures called spliceosomes. They are complexes of about 300 different proteins and also five RNA molecules, 100-300 bases long in higher eukaryotes, called small nuclear RNAs (snRNAs). These are associated with proteins in structures known as small ribonucleoprotein particles (snRNPs, pronounced 'snurps'), each containing multiple protein subunits. The spliceosome undergoes various rearrangements during different phases of the splicing reaction. These involve changes in the base pairing of snRNAs with the transcript and with each other. Several of the interactions and rearrangements require ATP hydrolysis, so although the transesterification itself does not involve energy changes, splicing is an energy requiring process.

Which of the following statements regarding splicing of eukaryotic mRNA transcripts is correct? a) Exons are spliced out and introns are retained in the mature mRNA transcript. b) Several reactions in the splicing process involve hydrolysis of ATP. c) Small nuclear RNAs are retained in the mature mRNA transcript. d) Splicing takes place in the cytosol.

Termination often involves a stem-loop structure forming in the RNA transcript. Feedback: At the end of many transcribed prokaryote genes are sequences that result in the transcribed RNA having a stem loop structure which somehow disrupts the elongation process. Immediately following the stem loop structure in the mRNA transcript is a string of around 8 U residues, giving weak bonding of the RNA to DNA because of weaker double A-U hydrogen bonding. This facilitates complete detachment of the mRNA and hence terminates transcription. An alternative method of termination of transcription in many prokaryote genes requires an additional protein called the Rho factor, which attaches to the newly transcribed mRNA and moves along it behind the RNA polymerase. At the termination site, the polymerase pauses, possibly because of a difficult to separate G-C-rich sections of the DNA, and this pause allows the Rho factor to catch up with the polymerase. The Rho factor has an unwinding (helicase) activity for unwinding the RNA-DNA duplex formed by transcription. ATP breakdown is involved. Unwinding releases mRNA and terminates transcription.

Which of the following statements regarding termination of transcription in prokaryotes is correct? a) In Rho dependent termination the Rho factor moves along the DNA template ahead of the RNA polymerase. b) Rho factor has topoisomerase activity for relieving supercoiling. c) Termination often involves a stem-loop structure forming in the RNA transcript. d) Termination often involves a stem-loop structure forming in the DNA template.

A) The genetic code is overlapping.

Which of the statements below is false? A) The genetic code is overlapping. B) The genetic code is universal. C) Degenerate codons specify the same amino acids. D) The genetic code is triplet.

D. All of the above

Which one is a nucleic acid polymerase? A. DNA polymerase B. RNA polymerase C. Telomerase D. All of the above

Methionine

Which one of the following amino acids is frequently found both at the N-terminus of a polypeptide chain in eukaryotic cells as a consequence of the initiation of translation and also internally in the polypeptide chain? A. Leucine B. Lysine C. Glutamine *D. Methionine

C) Insertion

Which one of these genetic lesions is likely to cause a frameshift mutation? A) Transversion B) Transition C) Insertion D) Missense mutation E) Point mutation

E. Poly A tail

Which part of an mRNA is not present in its corresponding DNA template? A. 5' UTR B. 3' UTR C. Intron D. Exon E. Poly A tail

D) enzymes

Which protein class directly controls many of the metabolic reactions within a cell? A) structural proteins B) repressor proteins C) operator proteins D) enzymes E) hydrophilic proteins

FISH

Which technique can be used to identify the location of genes on a chromosome?

DNA is synthesized 5' to 3'. Replication can only proceed from the unwound portion of DNA outward.

Why does lagging strand synthesis consist of discontinuous Okazaki fragments? A. There is a shortage of dNTPs for lagging strand synthesis. B. DNA is synthesized 5' to 3'. Replication can only proceed from the unwound portion of DNA outward. C. Lagging strand DNA polymerase can only handle a few nucleotides at a time. D. Okazaki fragments are riddled with mistakes; proofreading enzymes chop up the nucleotide into short fragments.

A. It does not contribute to enzymatic activity of the RNA polymerase

Why is sigma factor not considered part of the core enzyme? A. It does not contribute to enzymatic activity of the RNA polymerase B. It does not bind to the promoter C. A lot of bacteria species doe not have sigma factors D. It can be replaced by other subunits of the RNA polymerase

b) Because DNA polymerase can only synthesize in one direction

Why is the lagging strand of DNA replicated in short Okazaki fragments? a) Because DNA is tightly wound b) Because DNA polymerase can only synthesize in one direction c) To help with repair enzymes d) To help with proof reading

C. Cytosine degradation results in uracil. One common DNA mutation is the transition from cytosine to uracil in the presence of heat. DNA repair enzymes recognize uracil and correct this error by excising the base and inserting cytosine. RNA exists only transiently in the cell, such that cytosine degradation is insignificant. Were uracil to be used in DNA under normal circumstances, it would be impossible to tell if a base should be uracil or if it is a damaged cytosine nucleotide.

Why might uracil be excluded from DNA but NOT RNA? A. Uracil is much more difficult to synthesize than thymine. B. Uracil binds adenine too strongly for replication. C. Cytosine degradation results in uracil. D. Uracil is used as a DNA synthesis activator.

Transcription and splicing Explanation: In eukaryotes, transcription and splicing could occur simultaneously. Both of these processes take place in the nucleus of the cell, while translation takes place in the cytoplasm. Therefore, translation could not happen at the same time as either transcription or splicing. Replication occurs totally independently from all of the other processes listed.

Within a eukaryotic chromosome, which of the following pairs of processes can occur at the same time? Replication and splicing Translation and splicing Replication and transcription Transcription and splicing Transcription and translation

spliceosome

complex of enzymes that serves to splice out the introns of a pre-mRNA transcript

RNA polymerase

enzyme that unwinds DNA and then adds new nucleotides to a growing strand of RNA for the transcription phase of protein synthesis

tRNA corresponding to this DNA would have the anticodons: 3' UUA 5' 3' CUG 5' 3' CAG 5' Explanation: If the coding DNA reads 5' AATGACGTC 3', then the template strand would read 3' UUACTGCAG 5'. The mRNA transcription would read 5' AAUGACGUC 3'. The corresponding tRNA anti-codons would be 3' UUA 5' 3' CUG 5'; 3' CAG 5', which produce the amino acids Asn-Asp-Val. To determine the amino acid sequence, you find the portion of the genetic code table corresponding to the DNA or mRNA, not the tRNA, nucleotides. (That's why "Leu-Leu-Gln" is incorrect.)

f a given piece of coding DNA is 5' AATGACGTC 3', which of the following is true? tRNA corresponding to this DNA would have the anticodons: 3' UUA 5' 3' CUG 5' 3' CAG 5' The amino acid chain matching this DNA sequence is Leu-Leu-Gln tRNA corresponding to this DNA would have the anticodons: 3' AAU 5' 3' GAC 5' 3' GUC 5' tRNA corresponding to this DNA would have the anticodons: 5' UUA 3' 5' CUG 3' 3' CAG 5'

proteome

full complement of proteins produced by a cell (determined by the cell's specific gene expression)

transfer RNA (tRNA)

molecules of RNA that serve to bring amino acids to a growing polypeptide strand and properly place them into the sequence

C) in fragments.

n DNA replication, the lagging strand differs from the leading strand in that the lagging strand is synthesized: A) in a 5′ to 3′ direction. B) in a 3′ to 5′ direction. C) in fragments. D) using DNA polymerase. E) outside the replication bubble. C) tRNA The role of ______ is to carry amino acids to

b. sugar and phosphate

n a polynucleotide, the individual nucleotides are linked by bonds between _____. a. nitrogenous bases b. sugar and phosphate c. sugars d. phosphates e. nitrogenous base and sugar

TRUE

n forming a nucleotide, phosphate is most often attached to the nucleoside at the C-5′ position of the sugar.

exon

ne of the coding regions of an mRNA molecule that remain after splicing

intron

non-coding regions of a pre-mRNA transcript that may be removed during splicing

RNA, RNA polymerase, 3'-5', template, coding strand, RNA primer

ranscription is the synthesis of __________ directed by a DNA template by the enzyme __________. The DNA strand is read in the __________ direction. This DNA strand is called the __________. The RNA transcript is synthesized in the 5'-3' direction, and it has the same sequence as the 5'-3' strand of DNA, which is called the __________. Unlike DNA replication, no __________ is required to initiate transcription.

B. messenger RNA

ranscription results in A. an amino acid chain B. messenger RNA C. complementary DNA D. Okazaki fragments

promoter

region of DNA that signals transcription to begin at that site within the gene

A) transcription factors

regulate which genes or subsets of genes are transcribed in a particular cell type. . A) transcription factors B) chaperone proteins C) RNA polymerases D) transcription is not regulated

B) P, A

uring translation, the ____ site within the ribosome hold the growing amino acid chain while the ____ site holds the next amino acid to be added to the chain. A) A, P B) P, A C) A, B D) B, A