LC CH 10
In a sample of DNA, the percent concentration of guanine was found to be 32%. In accordance with the Chargaff's rules, what is the nucleotide ratio of adenine to cytosine? A 1(This would be the ratio between complementary base pairs (A/T) or (G/C)) B 1.78 (This would be the ratio if determining the ratio of cytosine to adenine.) C 0.56 D 0.50(This would be the ratio if comparing a single nucleotide with the total base pair concentration.)
0.56 The percentage of adenine would be 100 - (G+C) - T = A. From that calculation, dividing the adenine concentration from cytosine would provide the correct answer.
In a sample of DNA, the percent concentration of guanine was found to be 32%. In accordance with the Chargaff's rules, what is the nucleotide ratio of adenine to cytosine? (READ CAREFULLY! YOU ALWAYS MISS THIS ONE...) A 1 B 0.56 C 0.50 D 1.78
0.56 The percentage of adenine would be 100 - (G+C) - T = A. From that calculation, dividing the adenine concentration from cytosine would provide the correct answer.
What would the sequence of the complementary DNA strand be for the strand 5'-ATGCTAGGC-3'?
3'-TACGATCCG-5' This is an accurate depiction of the complementary strand.
What would the sequence of the complementary DNA strand be for the strand 5'-ATGCTAGGC-3'? A3'-TACGATCCG-5' B 5'-ATGCTAGGC-3' C 5'-TACGATCCG-3' D 5'-AUGCUAGGC-3'
3'-TACGATCCG-5' This is an accurate depiction of the complementary strand.
If the percentage of cytosine in a sample of DNA is 18%, what is the likely percentage of adenine?
32% The percentage of adenine would be 100 - (G+C) = A + T. The composition of A + T divided by two would be the percentage of adenine or thymine.
If the percentage of adenine in a sample of DNA is 34%, what is the likely percentage of thymine?
34% The base composition of adenine and thymine are equal so it would be 34%.
Question Value: 35 points If the percentage of adenine in a sample of DNA is 34%, what is the likely percentage of thymine?
34% The base composition of adenine and thymine are equal so it would be 34%.
Each sequence indicates one of two strands of a DNA molecule. When heated, which molecule would separate first?
5'-ATAATAACAT-3' The more A-T bonds, the easier it is to separate due to their two bond base activity.
You are studying genome mapping for a new species of fish. You find three different strands of DNA. One of the strands of DNA is shown. What third strand would most likely form a triplex structure with the other?5'-TCCCCCGATCCCCCCTTAGT-3' 5'-AGGGCCGGCCATCGGCACTA-3' 5'-ATCACGGCTACCGGCCGGGA-3' 5'-GCAAAGCCCGAATTTTCCCA-3' 5'-TCCCCCCTAGCCCCCTATCA-3'
5'-ATCACGGCTACCGGCCGGGA-3'
Jean is developing a genetics protocol based on base composition. From her sequencing data, she gathered that the ratio of (A + T) to (C + G) is 1:4, respectively. She also noted the RNA strand shown. What is the original DNA strand sequence and structure that is observed?5'-UAACCUACCGGGGGCCUCGGGCAU-3'
5'-ATGCCCGAGGCCCCCGGTAGGTTA-3'; Z-DNA This sequence is a complement of the RNA with bases of DNA. Due to the alternating strands of C and G, it could be assumed to take a Z-DNA configuration.
Dominique is studying virulence in a batch of E. coli. She isolates the DNA strand shown. Which of these sequences is a result of the strand's transcription into RNA?5'-TGCGATGCAATCAGCC-3' A 5'-GGCTGATTGCATCGCA-3' B 5'-ACGCUACGUUAGUCGG-3' C 5'-GGCUGAUUGCAUCGCA-3' D 5'-ACGCTACGTTAGTCGG-3'
5'-GGCUGAUUGCAUCGCA-3' This is the proper sequence that is complementary to the original strand.
Which of these sequences will most likely yield a Z-DNA structure configuration? A 5'-GGGCCCGGTACCCGGG-3' B 5'-ATTAATAGGCTAGCAT-3' C 5'-GCGAATAACGCTTATG-3' D 5'-GCGTTAAATGCTAGAT-3'
5'-GGGCCCGGTACCCGGG-3' This sequence has a high concentration of C and G sequences, so it would be the most likely to yield a Z-DNA configuration.
Each sequence indicates one of two strands of a DNA molecule. The two strands of which molecule would be held together most tightly? A 5'-AAAAAAAAAA-3' B 5'-ATATATATAT-3' C 5'-GAGAGAGAGA-3' D 5'-GGGGGGGGGG-3'
5'-GGGGGGGGGG-3' This molecule is held together by 30 hydrogen bonds.
Which enzyme or enzymes destroyed the transforming substance in Avery and colleagues' experiments?
DNase DNase destroys DNA, which is the genetic material responsible for transformation.
Which of these was not considered a key characteristic of genetic material even before nucleic acids were identified as the genetic material? A Genetic material must encode complex information. B Genetic material must have a complex structure. C Genetic material must encode the phenotype. D Genetic material must be copied accurately.
Genetic material must have a complex structure. Although many assumed that the structure of the genetic material would be complex, complexity was not a key feature required to explain its properties.
The tetranucleotide hypothesis said that DNA was not the genetic material because it did not support which of these assumptions?
Genetic material must have the capacity to vary. The tetranucleotide hypothesis considered protein as the genetic material due to its many variations, which contrasts with DNA as the source of genetic material.
An alternative hypothesis that Griffith had while analyzing his results was that the live IIR bacteria had mutated to the disease-causing S form. What result would he have gotten if this hypothesis were supported? A He would have isolated live IIIS bacteria from the disease-killed mice only. B He would have isolated dead IIIS bacteria from the disease-killed mice. C He would have seen mice die after injection with heat-killed IIR bacteria. D He would have seen killing with a mixed injection of live IIR and heat-killed IIIS and isolated live IIIS bacteria from disease-killed mice.
He would have seen killing with a mixed injection of live IIR and heat-killed IIIS and isolated live IIIS bacteria from disease-killed mice. Mixing of live and heat-killed bacteria will cause virulence and result in live IIIS bacteria being yielded from the disease-killed mice.
If Avery and his colleagues found that RNA was the transforming material, what would the results of their experiment look like? A Only type IIR bacteria would be isolated from the protease-treated filtrate. B Only type IIR bacteria would be isolated from the RNase-treated filtrate. C Only type IIR bacteria would be isolated from the DNase-treated filtrate. D Only type IIIS bacteria would be isolated from the RNase-treated filtrate.
Only type IIR bacteria would be isolated from the RNase-treated filtrate. Once IIR is isolated, it can be seen that the strain is now virulent with RNA as the transforming material.
If Avery and his colleagues found that RNA was the transforming material, what would the results of their experiment look like? Only type IIR bacteria would be isolated from the RNase-treated filtrate. Only type IIR bacteria would be isolated from the DNase-treated filtrate. Only type IIR bacteria would be isolated from the protease-treated filtrate. Only type IIIS bacteria would be isolated from the RNase-treated filtrate.
Only type IIR bacteria would be isolated from the RNase-treated filtrate. Once IIR is isolated, it can be seen that the strain is now virulent with RNA as the transforming material.
In Hershey and Chase's experiment, they noticed that they could recover little to no radioactive sulfur from the infected bacteria. What did this suggest?
Protein from the phage did not enter the cell and, therefore, could not be the genetic material. Sulfur is indicative of protein so, if there was little to none recovered, it can be assumed that protein did not enter the cell.
Which of these is not a part of a nucleotide? A a phosphate B a sugar C an -R group D a nitrogen-containing base
R group
In Hershey and Chase's experiment, they found that progeny phages contained radioactive phosphorous. What did this suggest?
Radioactive phage DNA not only entered the bacterial cell but was also passed on to the phage progeny. The presence of genetic traits in the progeny is the result of inheritance from one generation to the next.
If Levene's tetranucleotide hypothesis was correct, what nucleotide ratios would Chargaff find?
The amount of all the nucleotides would have been the same. This would demonstrate the lack of variability that was proposed by the tetranucleotide hypothesis.
Which statement about DNA and RNA is NOT true? A DNA sugars lack an O atom compared to RNA sugars. B DNA contains the bases A, G, C, and T, while RNA contains A, C, G, and U. C Both DNA and RNA nucleotides include five-carbon sugars. D Both DNA and RNA include pyrimidine and purine bases.
The ans said B but.... ????
Which of these statements is NOT consistent with Chargaff's findings about the composition of DNA? A The combined amount of adenine and thymine is equal to the combined amount of guanine and cytosine. B The combined amount of adenine and guanine is equal to the combined amount of thymine and cytosine. C The amount of adenine is equal to the amount of thymine. D The amount of guanine is equal to the amount of cytosine.
The combined amount of adenine and thymine is equal to the combined amount of guanine and cytosine. The percentage of A-T base pairs and G-C base pairs in DNA varies from sample to sample.
Which of these statements is NOT consistent with Chargaff's findings about the composition of DNA? A The combined amount of adenine and thymine is equal to the combined amount of guanine and cytosine. B The amount of guanine is equal to the amount of cytosine. C The combined amount of adenine and guanine is equal to the combined amount of thymine and cytosine. D The amount of adenine is equal to the amount of thymine.
The combined amount of adenine and thymine is equal to the combined amount of guanine and cytosine. The percentage of A-T base pairs and G-C base pairs in DNA varies from sample to sample. (REMEMBER A and T/ G and C pair together, so they are the same percentages A/T=G/C each ratio equals 1)
Which of these statements is correct concerning the sequence shown? 5'-ACGTACCGTACTAGCAGCTA-3' A The sequence when bound will form a Z-DNA formation. B The ratio of (A + T) / (C + G) is less than 1. C The sequence can assume two hairpin stem configurations sequentially. D The RNA complement is 5'-UAGCUGCAAGUACGGUACGU-3'.
The sequence can assume two hairpin stem configurations sequentially. As a single strand, the sequence has the ability to bind base pairs to form hairpin stems and loop structures. With this particular sequence, two hairpin structures can be formed.
Which of these statements is correct concerning the sequence shown?5'-ACGTACCGTACTAGCAGCTA-3' A The sequence can assume two hairpin stem configurations sequentially. B The RNA complement is 5'-UAGCUGCAAGUACGGUACGU-3'. C The ratio of (A + T) / (C + G) is less than 1. D The sequence when bound will form a Z-DNA formation.
The sequence can assume two hairpin stem configurations sequentially. As a single strand, the sequence has the ability to bind base pairs to form hairpin stems and loop structures. With this particular sequence, two hairpin structures can be formed.
In Hershey and Chase's experiment, phage protein was radiolabeled with sulfur, and phage DNA was radiolabeled with phosphorous. If their hypothesis was that DNA was the genetic material, in what sample would they expect to find radioactive phosphorous? A both pellet of phage-infected bacteria and progeny of phosphorous-labeled phage B fluid containing sheared-off virus coats after centrifugation C progeny of phosphorous-labeled phage only D pellet of phage-infected bacteria only
both pellet of phage-infected bacteria and progeny of phosphorous-labeled phage Both of these samples would yield radioactive phosphorus if DNA is the genetic material.
Consider this sequence. Which, if any, type of secondary structure might this DNA form? 5'- CGTTACGTATAACGTAACG - 3'
hairpin There would an extra set of nucleotides that would create an inversion in the structure such as the hairpin with a loop. (LOOK AT BOTH ENDS! THEY COMPLIMENT ONE ANOTHER SO STICK TOGETHER AND FORM HAIRPIN)
Which structure is a common formation of secondary DNA structure?
helix The helix is the common form of secondary DNA structure.
Heating a double-stranded DNA molecule will cause chemical bonds to break. Which bonds will break first, resulting in separation of the DNA molecule?
hydrogen bonds between bases on opposite strands Hydrogen bonds are weaker bonds especially between bases of distance.
Injection by Griffith of which sample of Streptococcus pneumonia yielded surprising results that indicated that transformation had occurred?
living IIR + dead IIIS This injection produced pneumonia due to transformation of IIR cells into IIIS cells by taking up DNA from the dead IIIS cells.
What information cannot be derived from studying the genome of an individual? A ancestral information such as closest relatives both past and present B genotypic information such as sequence of particular genes C phenotypic information such as the individual's blood type or skin color D personality information such as willingness to take risks and sense of humor
personality information such as willingness to take risks and sense of humor The genome can dictate the genotype and phenotype of an individual, but the environment plays more of a part in external behavior.
Normally, a _____ group protrudes from the 5' end of a polynucleotide strand.
phosphate The phosphate group is attached to the 5' end of the sugar.
The sequence 5'-CCGTAATCG-3' describes the _____ structure of DNA.
primary The primary structure is simply the order of nucleotides in a strand of DNA.
What material did the tetranucleotide hypothesis propose was the genetic material in cells?
protein The tetranucleotide hypothesis supported that proteins were the source of genetic material due to their capacity to vary greatly compared with DNA.
The final product of a gene is often a
protein. Proteins are the result of gene replication for phenotypic expression.
A graduate student hoping to specialize in virology is studying the process of viral DNA integration within host cells by bacteriophages. If they desire to configure a means of mitigating that integration, which of these steps would not help in decreasing bacteriophage replication?
removal of phage head after host attachment Removing the phage head would not be beneficial as the DNA has already been injected into the cell.
Hershey and Chase take advantage of all these important aspects of bacteriophage biology in their experiments, except A that phages cannot replicate on their own and require a host cell. B that phages are made up of protein and DNA. C that phages inject only DNA, not protein, into the host cell. D that phages only carry RNA as genetic material.
that phages only carry RNA as genetic material. Phages carry DNA as their genetic material.
Which of these does not affect the three-dimensional shape of a DNA molecule? A amount of water surrounding the DNA molecule(The shape of DNA can be altered based on the hydrophilicity of the DNA molecule.) B the type of RNA molecule it encodes C the sequence of the DNA strands (The sequence of the DNA strands can shift the variance in stacking, altering the structural shape of the molecule.) D what type of cell the DNA molecule is in
the type of RNA molecule it encodes DNA conformation is not dependent on RNA.
Griffith determined that, through _____, nonlethal bacteria had _____ genetic virulence leading to a _____ genetic change in the bacteria.
transformation; acquired; permanent This is the principle of transformation that would even be seen in the progeny of the bacteria.
Which finding helped disprove the tetranucleotide hypothesis (Levene first proposed that DNA was made up of equal amounts of adenine, guanine, cytosine, and thymine)? A There are 20 different amino acids. B DNA consisted of adenine, guanine, cytosine, and thymine. C Base composition varied greatly between organisms. D The amount of adenine is always equal to the amount of thymine.
Base composition varied greatly between organisms. A difference in base composition distinguishes variability between individual organisms. No individual organism can be considered to have the same DNA base composition, disproving the lack of variability with the tetranucleotide hypothesis.
Which finding helped disprove the tetranucleotide hypothesis?
Base composition varied greatly between organisms. A difference in base composition distinguishes variability between individual organisms. No individual organism can be considered to have the same DNA base composition, disproving the lack of variability with the tetranucleotide hypothesis.
An alternative hypothesis that Griffith had while analyzing his results was that the live IIR bacteria had mutated to the disease-causing S form. What result would he have gotten if this hypothesis were supported? A He would have seen mice die after injection with heat-killed IIR bacteria. BHe would have seen killing with a mixed injection of live IIR and heat-killed IIIS and isolated live IIIS bacteria from disease-killed mice. C He would have isolated dead IIIS bacteria from the disease-killed mice. D He would have isolated live IIIS bacteria from the disease-killed mice only.
He would have seen killing with a mixed injection of live IIR and heat-killed IIIS and isolated live IIIS bacteria from disease-killed mice. Mixing of live and heat-killed bacteria will cause virulence and result in live IIIS bacteria being yielded from the disease-killed mice.
Why did Levene propose that protein was the genetic material of cells and not DNA?
It has more variation potential. Levene concluded that, due to an increased capacity of variance with proteins, DNA would not be the genetic material of cells.
Which of these statements is true concerning the primary purpose of centrifugation in the Hershey-Chase experiment?
It properly separates protein from cells for proper evaluation. The centrifuge separates the components, forming a pellet for analysis.
Chris is a graduate assistant analyzing changes in DNA through methylation. He has isolated a strand of DNA from E. coli, S. boulardii, and from rosemary. Which of these are conclusions Chris can consider concerning these strands? A The methylation of E. coli is purposed for infection resistance and has no structural influence. (WRONG The methylation of bacteria does resist foreign DNA, but it also affects the primary structure of DNA) B There is no standard for methylation in rosemary due to the variance among eukaryotes. C It is likely methylation serves the same purpose in all three strands of DNA. (WRONG Methylation serves different purposes in bacteria and eukaryotes.) D Methylation has no effect on the level of gene expression in rosemary.(WRONG Methylation can reduce the level of gene expression in eukaryotic cells.)
There is no standard for methylation in rosemary due to the variance among eukaryotes. Due to the variance in eukaryotic organisms, the level of methylation varies from one to the other.
In Fraenkel-Conrat and Singer's experiments using the tobacco mosaic virus (TMV), what result led them to believe that RNA was the virus's genomic material?
There were two different types of TMV. Since the virulent strain was reflective of one type of TMV, it can be assumed that strain carries virulence.
Which of these is a CORRECT statement about nitrogenous bases? A Thymine and uracil are both pyrimidines. B Cytosine is a pyrimidine in DNA and a purine in RNA. C Purines consist of a six-member ring only. D Only RNA contains pyrimidines
Thymine and uracil are both pyrimidines. Thymine, uracil, and cytosine are pyrimidines.
In his experiments, Griffith found that when he injected live IIR (not disease causing) bacteria with heat-killed IIIS (disease causing) bacteria, the mice died of pneumonia. He was able to isolate live IIIS bacteria, implying that the nonvirulent IIR type had been transformed with DNA from the virulent IIIS. When injected into mice, the isolated IIIS bacteria were still able to cause disease over several generations. What does this suggest about transformation?
Transformation resulted in a heritable change in DNA content of the receiving cell. The inheritance would increase the prevalence of disease-causing traits in cells without the need for transformation.
Stanley is sequencing a new species in the genetics laboratory. He determines to note his findings in order to uncover the structure that he is observing. What type of DNA configuration can be assumed based on the data? DNA parameters Observation Type of helix left-handed Helical diameter 1.6 nm Base orientation angled toward from main axis
Z-DNA Z-DNA is the only left-handed helix to note and meets the criteria for the data presented. (BDNA= Rhanded, exist when water abundant, 2ndary structure described by watson&crick, most common/stable DNA in cells, diameter=2nm, bases perpendicular to long axis of DNA molecule) (ADNA= Rhanded, exists when little water present, bases tilted away from main axis, shorter/wider than BDNA)
