Quiz 2 Flashcards
The bacterial chromosome is
both circular and found in a nucleoid
The function of PCNA is
to work as a sliding clamp
Which of the following relationships about nucleotide composition in DNA is TRUE?
C+A=G+T
The transfer of DNA fragments from a dead cell to a live, competent recipient cell that results in a changed recipient cell is
transformation
Beginning with the simplest level of structure, which order of organization of genetic material is CORRECT?
nucleotide, DNA, gene, chromosome, genome
Why are the complementary base pairing rules so important when a cell needs to copy its DNA?
As long as there is one strand, a copy can be made by following the pairing rules.
The enzymes that can proofread replicating DNA, detect incorrect bases, excise them and correctly replace them are
DNA polymerases
Which protein influences the ability of RNA polymerase to transcribe genes?
transcription factors
Which of the following would occur if a cell’s splicesomes were mutated so they no longer functioned normally?
Introns would remain in the mature mRNA.
Which of the following statements is TRUE about protein synthesis in prokaryotes?
Translation can begin while transcription is still in progress.
Ribozyme is an
RNA with enzymatic activity
Transcription begins near a site in the DNA called the ________, while the terminator specifies the end of transcription.
promoter
Accuracy in the translation of mRNA into the primary structure of a polypeptide depends on specificity in the
bonding of the anticodon to the codon and the attachment of amino acids to tRNAs.
New antibiotic is developed that interferes with the way tRNA fits into bacterial ribosomes. How would this kill?
The bacteria would be unable to produce necessary enzymes to carry out basic metabolism.
Which of the following proteins is involved in synthesizing messenger RNA in eukaryotes?
RNA polymerase II
Analysis of DNA fragments in gel electrophoresis involves
Larger fragments move slowly and remain closer to the wells
DNA has an overall negative charge and moves to the positive pole
DNA fragments are stained with fluorescent dye ethidium bromide to see them
An electric current through the gel causes DNA fragments to migrate
Which choice is an example of “recombinant DNA”?
A bacterial plasmid combined with a human gene
How does a bacterial cell protect its own DNA from restriction enzymes?
by adding methyl groups to adenines and cytosines
You have a small gene that you wish replicated by PCR. After 3 replication cycles, how many double-stranded DNA molecules do you have?
8
A small amount of DNA is collected from a crime scene. However, the amount of DNA collected is insufficient to perform the necessary experiments to link a suspect to the crime. What method could be utilized to increase the amount of DNA?
polymerase chain reaction (PCR
Which of the following is an advantage of cDNA libraries?
cDNA lacks introns and reflects all the genes expressed by a particular tissue or organism.
A student wishes to clone a sequence of DNA of ~200 kb. Which vector would be appropriate?
A BAC
To carry out hybridization, why is DNA transferred from a gel to a nitrocellulose paper?
to attach the DNA fragments to a permanent substrate
For PCR, DNA is denatured at
95 C
Which of the following is TRUE regarding the step in gene cloning when bacterial cells take up recombinant vector?
The cell is treated with agents that render it permeable to the plasmid.
When a/n _____________________ binds to the repressor, then the repressor binds to the operator.
co-repressor
While synthesizing DNA, the polymerase moves along the parental strand in ______________ direction.
3’ to 5’
The ___________________ recognizes a stop codon at the A site of the ribosome.
release factor
Enzymes called __________________________ relieve torsional stress that develops in cellular DNA molecules during replication and other processes.
topoisomerases
The temperature at which half the bases in a double-stranded DNA sample have denatured is denoted as
Tm
