bio unit 7
What is a plasmid?
a circular piece of DNA in prokaryotes
Which of the following molecules is acted on by a spliceosome?
rna
According to Tatum and Beadle's hypothesis, how many genes are necessary for this pathway?
2
Which of the following best describes the complete sequence of steps occurring during every cycle of PCR?
2, 1, 3
Given the locally unwound double strand above, in which direction does the RNA polymerase move?
3' to 5' along template strand
Which of the following occurs to the RNA transcript before a gene can be expressed?
A poly-A tail is added to the 3' end and a GTP cap is added to the 5' end.
A mutation results in a defective enzyme 1. Which of the following would be a consequence of that mutation?
An accumulation of A and no production of B and C.
If large amounts of the product were injected into the posterior end as well, which of the following would occur?
Anterior structures would form in both ends...
Where does tRNA #2 move to after this bonding of lysine to the polypeptide?
E site
What is the most logical sequence of steps for splicing foreign DNA into a plasmid and inserting the plasmid into a bacterium?
III, II, IV, V, I
What is the effect of a nonsense mutation in a gene?
It introduces a premature stop codon into the mRNA.
Which site in the ribosome complex would a new tRNA (#3) first enter to check for codon/anti-codon match?
P site
Which of the following statements about the DNA in one of your brain cells is true?
Same dna as your liver cells
The first cloned cat, called Carbon Copy, was a calico. Why would she look significantly different from her female parent?
X inactivation in the embryo is random and produces different patterns.
Which of the following types of mutation, resulting in an error in the mRNA just after the AUG start of translation, is likely to have the most serious effect on the polypeptide product?
a deletion of two nucleotides
What is the function of the release factor (RF)?
binds to stop codon in place of tRNA
The lactose operon is likely to be transcribed when
cyclic AMP and lactose levels are both high
Which component is NOT directly involved in translation?
dna
A frameshift mutation could result from
either an insertion or a deletion of one base.
DNA methylation and histone acetylation are examples of
epigenetics.
There are 61 mRNA codons that specify an amino acid, but only 45 tRNAs. This is best explained by the fact that
more than one codon can code for the same amino acid.
Which region of DNA would indicate the beginning of the promoter region for transcription?
tata box
In comparing DNA replication with RNA transcription in the same cell, which of the following is true only of replication?
the entire template molecule is represented in the product
What is the process of formation of mRNA from DNA?
transcription
Bacterial cells that have picked up DNA from the surrounding medium are said to have undergone
transformation
A particular triplet of bases in the template strand of DNA is 3' - AGT - 5'. The corresponding codon for the mRNA transcribed is
5'-UCA-3"
The genetic code is essentially the same for all organisms. From this, one can logically assume which of the following?
A gene taken from one organism can theoretically be expressed by another organism.
Which of the following tools of recombinant DNA technology is incorrectly paired with its use?
DNA ligase cutting DNA
In 1997, Dolly the sheep was cloned. Which of the following processes was used?
Fusion of an adult cell's nucleus with an enucleated sheep egg, followed by incubation in a surrogate.
Which of the following is the correct statement regarding histone acetylation?
Histone acetylation allows genes on the DNA to be read.
a mutant where the gene for enzyme 2 is turned off would be capable of growing on which of the following media?
Minimal medium supplemented with C only.
The dipeptide that will form will be
Proline-Threonine.
Which of the following modifications must be made to an RNA molecule before it leaves the nucleus?
Spliceosomes must cut out the introns.
Which of the following describes the electrophoresis of protein sequences?
Western blotting
A molecule like tryptophan will bind to a repressor, activating it so that the repressor can now bind to the operator and turn off operon genes. What is this type of molecule called?
co-repressor
A mutation that inactivates the regulatory gene of a repressible operon in an E. coli cell would result in
continuous transcription of the structural gene controlled by that regulator
You have a plasmid with a single site for Y, but not for X. Your strategy should be to
cut plasmid twice with restriction enzyme Y and ligate the two fragments onto the ends of DNA fragments cut with restriction enzyme X
Muscle cells differ from nerve cells mainly because they
express different genes.
If you were to observe the activity of a section of DNA has is heavily methylated, you would expect it to
have turned off or slowed down the process of transcription
A molecule like lactose, when taken up by the cell, binds to the repressor so that the repressor is inactivated and no longer binds to the operator. What is this type of molecule called?
inducer
Which enzyme was used to produce the molecule in Figure 20.1 above?
ligase
To compare a specific region of the DNA from the sample with DNA from living birds, which of the following would be most useful for increasing or amplifying the amount of dodo DNA available for testing?
polymerase chain reaction (PCR)
The anticodon of a particular tRNA molecule is
the complimentary to the corrresponding mRNA codon
Which of the following is the very first event to take place at the ribosome in translation in eukaryotes?
the small subunit of the ribosome recognizes..
The tryptophan operon is a repressible operon that is
turned off whenever tryptophan is added to the growth medium.
In the transcription event of the DNA, where would the promoter be located?
upstream of the template strand
