From the old exam
After sigma factor guides the RNA polymerase to the correct promoter site, it:
dissociates from the core enzyme
The end of an RNA from a bacterial gene is likely to contain
Inverted repeats and a string of U’s
Hershey and Chase differentiated between DNA and protein by:
labeling the DNA with 32Phosphorous, proteins with 35Sulfur
Contains a guide RNA used as a template
Maintains the single-strand form of DNA
Actually synthesizes RNA, not DNA
Is often overactive in cancer cells
Coordinate replication requires two
DNA Pol III
Opens the double helix for replication machinery
After several generations of labelling in 15N media, Meselson and
Stahl switched to 14N media for one generation. The DNA
after one generation in 14N media was centrifuged in a cesium gradient. The DNA formed a single band with a density somewhere between
DNA grown in 15N media and DNA grown in 14N media. This data is consistent with:
semiconservative and dispersive replication
For double-stranded DNA, which of the following base ratios usually does not equal 1
The form of DNA normally found in our cells is
The function of DNA ligase is to
Catalyze the formation of covalent bonds between adjacent 5'-P and 3'-OH termini
The pyrimidine bases are
Thymine and cytosine
Acts in a distance and orientation independent fashion
Produces large quantities of a few large polymers
RNA Polymerase I
CAAT box or GC box
RNA Polymerase III
a protein which binds to TATA boxes
a protein shaped like an RNA
Required for translocation of ribosome
tRNA entry site
ribosomal RNA genes
middle repetitive DNA
The correct order of activity in replication is
helicase, SSB, primase, Pol III, Pol I, ligase
Which of these RNA sequences could form a hairpin also called a stem loop?
5′ GGGGTTTTCCCC 3′
By measuring the UV-melting curves for the DNA of two different
organisms (A and B) in the same solution and
concentration, we have found the following melting temperatures (Tm): Tm(A)= 70.2 C and Tm(B)=75.6 C. Which of
the following is correct
B has more guanine than A
RNA primer synthesis
3′ -->5′ exonuclease activity
phosphodiester bonds at DNA nicks
5’ -->3’ polymerase activity
5’--> 3’ exonuclease activity
Which is a mechanism that allows a single gene to encode more than one polypeptide?
Alternative RNA splicing
If the sequence of an RNA molecule is 5’-GGCAUCGACG-3’, what is the
sequence of the template strand of
An in vitro transcription system transcribes a bacterial gene but
terminates inefficiently. What is one possible
Rho factor has not been added
Occurs on the DNA strand synthesized overall in the 3' to 5' direction. Results in the formation of Okazaki fragments
Termination of transcription in prokaryotes is carried out in part by a
stem loop or hairpin structure
The P site in the ribosome is named for
The signal for polyadenylation of the mRNA is
Which of the following statements regarding gene expression is true?
Messenger RNA is translated in the 5' to 3' direction
The genetic code is said to be redundant because
Several codons direct the insertion of the same amino acid into a polypeptide chain
Which of the following is not present as a dimer in a histone core
Interacts with A site when ribosome is on a stop codon
helps assemble large and small ribosomal subunits
carries the anticodon
charges the tRNA
Participates in addition of an amino acid to a growing polypeptide chain
Which level of protein structure includes alpha helix and beta pleated sheet
Which of the following is not different between eukaryotic and
prokaryotic transcription a) Splicing b) 5' capping c)
poly-adenylation d) termination
e) all are different
e) all are different
Which one of the following is not a stop codon
A DNA molecule of 500 bp will have approximately how many turns?
Synthetic mRNAs were used to predict the genetic code. Which of the following is not true
repeats of three nucleotides produce a polymer with a three amino acid repeat unit
The corepressor of tryptophan biosynthesis is
Which feature of gene regulation is present only in eukaryotes
Insertion sequences (IS) inserted in the genome are flanked by:
Direct genomic repeats and inverted sequence elements
Which feature of gene regulation is present only in prokaryotic genomes?
Which of the Following is true for recombination?
Inversions interfere with recombination, reciprocal translocations with forming gametes with the correct chromosome balance
Which level of protein structure deals with just the sequence of amino acids
the Meselson Stahl experiment differentiating the modes of
replication by labeling with different forms of nitrogen and spinning
cesium gradient, how many rounds of replication were needed to determine if the following modes of replication were not used in E. coli?
two rounds of replication for dispersive; one round of replication for conservative
A bacterium has positively supercoiled DNA. This is likely because
The bacteria normally grow in high temperature conditions
A bacterium inherits a mutation that renders its gyrase enzyme nonfunctional. What phenotype would you expect to see in this bacterium?
The cell would accumulate broken DNA because overwinding cannot be corrected, so the cell will be unable to replicate and will die.
What is meant by the "beads on a string" model of chromatin?
The beads are the nucleosomes, and the string is the linker DNA
A cell can form beads on a string chromatin, but not solenoid fibers. Which molecule has likely been removed or mutated in this cell?
How does the eukaryotic initiation complex locate the true start codon?
The true start codon is the first ATG encountered downstream of the Kozak sequence.
You want to design a drug that prevents transcription of mRNAs but does not affect transcription of other RNAs. What enzyme would you target?
RNA polymerase II
Which type of RNA is translated within a cell?
In 1928, Griffith found that injecting which strains of Pneumococcus caused the mouse to die?
heat-killed type SIII and living type RII
Which of the following are classified as pyrimidines?
thymine and cytosine
What enzyme(s) is/are responsible for removal of RNA primers and joining of Okazaki fragments?
DNA polymerase I and DNA ligase
Which one of the following statements is not true for all E. coli DNA polymerases?
They possess 5'to 3' exonuclease activity.
Which statement is true regarding negative supercoiled DNA?
Negative supercoiled DNA is under-rotated and allows for easier strand separation during replication and transcription
What would Avery, Macleod, and McCarty have concluded if their results had been that only RNAse treatment of the heat-killed bacteria prevented transformation of genetic virulence?
RNA is the genetic material
Okazaki fragments are found associated with
After the first round of replication, Meselson and Stahl saw only one DNA band of density intermediate to DNA containing only 15N or 14N. After this observation, which hypothesis for DNA replication could be eliminated ?
DNA synthesis in eukaryotes is?
According to Chargaff’s rules, if a genome is 30% adenine, then what percentage of the genome should be guanine