Molecular Genetics Test
what is a label
14N and 15N
Based on Chargaff's rules, the percentage of cytosine in the DNA of the bacterium S Lutea should be around
26.6%
If a DNA sample contains 13% adenine, what percentage of the sample contains cytosine?
37%
DNA pol I removes the primer from ________ end of the 2nd fragment replacing it with DNA nucleotides that it adds one by one to the 3' end of the 3rd fragment. The replacement of the last RNA nucleotide with DNA leaves the sugar-phosphate backbone with a free 3' end.
5'
At a specific area os a chromosome the following sequence of nucleotides is present where the chain opens to form a replication fork, 3' CCTAGGCTGCAATCC 5' An RNA primer is formed starting at the underlined T of the template. Which represents the primer sequence?
5' ACGUUAGG 3'
The leading strand is synthesized continuously in the ____________
5' to 3' direction by DNA pol III
how did Avery's experiment build on griffith's findings
Avery found the transformation factor in the experiment but didn't know what it was
A space probe returns with a culture of microorganism found on a distant planet. Analysis shows that it is carbon based life form that has DNA. You grow the cells in 15N medium for several generations and then transfer them to 14N medium. Which tube would you find if the DNA was replicated in a conservative manner.
B
In trying to determine whether DNA or protein is the genetic material, Hershey and Chase made use of what fact
DNA contains phosphorus, whereas protein does not
how did the hershey-chase experiment provide evidence that nucleic acids not protein are the hereditary material
DNA is a nucleic acid and that is considered the hereditary material so it wouldn't be proteins
what assumptions were made about the role of DNA in viruses and bacterial and the role of DNA in eukaryotes
DNA is the only material transferred directly from the phage to bacteria when it is infected
______ ______ bonds the 3' end of the 2nd fragment to the 5' end of the 1st fragment
DNA ligase
What enzyme removes the RNA nucleotides from the primer and adds equivalent DNA nucleotides to the 3' end of Okazaki fragments
DNA polymerase I
which enzyme catalyzes the elongation of a DNA strand in the 5' to 3' direction
DNA polymerase III
A new DNA strand elongates only in the 5' to 3' direction because
DNA polymerase can only add nucleotides to the free 3' end
what did Avery's experimental results show
DNA was the transformation factor
DNA was shown to be the transforming substance when only the _____________ enzymes could inhibit transformation
DNAase
What investigator was responsible for the following discovery? In DNA from any species, the amount of adenine equals the amount of thymine, and the amount of guanine equals the amount of cytosine
Erwin Chargaff
what was Griffith's experiment
His experiment tested mice and pneumonia. He gave mice either rough or smooth strands of the virus, and sometimes heat killed the sample of the virus. He found that when he put live rough virus and heat killed smooth, the rough transferred its genetic material to the smooth one.
Who conducted the pulse-chase experiment
Matthew Meselson and Franklin Stahl
What was the Hershey-Chase experiment?
Phosphorus labeled core(DNA) and sulfur labeled cap (protein)
What is not true about DNA replication
Replication occurs as each base pairs are held together with hydrogen bonds
what is meant by the description "antiparallel" regarding the strands that make up DNA
The 5' to 3' direction of one strand runs counter to the 5' to 3' direction of the other strand
What was the Avery-MacLeod-McCarty Experiment
They tested each component of heat killed S cells separately as they inserted them into R cells to find the Transforming Principle
what do bacteriophages infect
bacteria
What property of DNA does bacterial transformation illustrate?
bacterial DNA can move into another bacteria and function
what is the pulse
cells that are exposed to a label compound
what will the tubes look like for a conservative replication
dark and light (gen 0 is dark)
Primase begins synthesis of RNA primer for ____________
fifth Okazaki fragment
DNA pol III is completing synthesis of the ______ _______ when it reaches the RNA primer on the third fragment it will dissociate move to the replication fork, and add DNA nucleotides to the 3' end of the fifth fragment primer
fourth fragment
griffith did not predict transformation in his experiment, what results was he expecting
he was expecting once the cells were dead nothing would happen, but then the transformation factor occurred
What enzyme separates the DNA strands during replication
helicase
Nucleotides do not contain what
histones
What is the role of DNA ligase in the elongation of the lagging strand during DNA replication
it joins Okazaki fragments together
DNA replication is considered semiconservative because
it uses the original stand as a template for replication
what will the tubes for dispersive replication look like
light on top (gen 0 is only dark)
what will the tubes look like for a semiconservative replication
light on top with a hybrid below it (dark is only at gen 0)
Which bacteria killed the mice in Griffith's transformation experiment?
live, harmless bacteria and heat-killed, harmful bacteria
what is inside a bacteriophage
nucleic acid
Rosalind Franklin contributed to the understanding of DNA by
producing images of DNA molecules using X-rays
Replication in prokaryotes differs from replication in eukaryotes for what reason
prokaryotic chromosomes have a single origin of replication whereas eukaryotic chromosomes have many
What is the function of topoisomerase
relieving strain in the DNA ahead of the replication fork
What helps hold the DNA strands apart while they are being replicated
single-strand binding proteins
in the hershey-chase experiment what happened to the bacteria that had been infected by the viruses that had radioactive DNA and to the bacteria that had been infected with viruses that had been marked with radioactive proteins
the bacteria infected with viruses that had radioactive DNA had become radioactive. The bacteria that had been infected with the viruses marked with radioactive proteins were not radioactive
how would the results of the experiment have differed if proteins carried the genetic information
the genetic information would be stored in a different place
Griffith called the process he observed transformation because
the harmless bacteria had been transformed
The leading and the lagging strands differ in that
the leading strand is synthesized in the same direction as the movement of replication fork, and the lagging strand is synthesized in the opposite direction
What happened when Griffith injected mice with the harmless, R-strain bacteria alone?
the mouse lived
what is the chase
the unlabeled form replaces the labeled compound
Molecules of single-strand binding protein stabilize ________
the unwound template strands
Griffith's experiments advanced the study of genetics by proving that
there is a chemical that contains genetic information that can be passes from one organism to the other
what is a pulse-chase experiment
two-phase technique used to examine cellular processes that take place over a period of time
Helicase _________________
unwinds the parental double helix