Genetics Test IV (Ch. 13, 14, 20, 26, Human Nature movie)
from left to right (The ribosome reads the mRNA in the 5' to 3' direction, and synthesizes protein from the N-terminal end to the C-terminal end. The mRNA is oriented with the 5' end on the left and the 3' end on the right. This indicates that translation is proceeding from left (5') to right (3').) 40s 60s (The subunits present depend on whether the ribosome is eukaryotic (40S and 60S) or prokaryotic (30S and 50S).)
*image of translation in eukaryotes, q. 1 of ch. 14 MB review* shows 5' cap, EPA, N term entering P, 3' What is the direction of translation in this diagram? from left to right from right to left unable to be determined Which protein subunits are depicted in the diagram? Select all that apply. 30S 40S 50S 60S
White colonies that are resistant to tetracycline The presence of blue colonies means that the plasmid taken up by these bacteria is recombinant, since the lacZ gene was disrupted.
A DNA fragment is introduced into the lacZ gene of a plasmid, which also contains a tetracycline resistance gene. What is the appearance of bacteria transformed with this plasmid if they are spread on plates containing tetracycline and Xgal? Blue colonies that are resistant to tetracycline Blue colonies that are sensitive to tetracycline White colonies that are resistant to tetracycline White colonies that are sensitive to tetracycline
one of the primers did not bind
A PCR was designed to clone a DNA sequence of 1.5 kb. When the products were run on an agarose gel, there was a smear of bands ranging from 1.5 kb to 6 kb. Which of the following is a reason for this result? the thermocycler malfunctioned the polymerase overran the reverse primer the polymerase denatured one of the primers did not bind
a loss-of-function PFKL mouse
A knock-out mouse is made with respect to the PFKL gene, and this mouse is now described as which of the following? a gain-of-function PFKL mouse a loss-of-function PFKL mouse an enhancement-of-function PFKL mouse a retention-of-function PFKL mouse
The next tRNA would not be able to enter the A site of the ribosome.
A mutation in EF-Tu would have a DIRECT effect on which part of translation? -Translocation would be directly blocked. -The polypeptide would form, but translation termination would be blocked. -The small and large subunits would not bind. -The next tRNA would not be able to enter the A site of the ribosome. -The peptide bond formation would be blocked.
that creates a termination codon Rationale A nonsense mutation changes an amino acid coding codon to a termination codon.
A nonsense mutation is a mutation _____. -that alters the reading frame -that changes the amino acid sequence of the gene product -that creates a termination codon -that allows a ribosome to bypass termination codons
Genetic diversity may better adapt a population to inevitable changes in the environment.
A number of mechanisms operate to maintain genetic diversity in a population. Why is such diversity favored? -Greater genetic diversity increases the chances of haploidy. -Homozygosity is an evolutionary advantage. -Diversity leads to inbreeding advantages. -Genetic diversity may better adapt a population to inevitable changes in the environment. -Genetic diversity helps populations avoid diploidy.
The protein coded by this mRNA would be shorter.
A particular mRNA is 300 nucleotides long. If a mutation in the middle of the sequence changed a codon from a AAA to a UAA then what would be a reasonable prediction? -The protein coded by this mRNA would be shorter. -The protein coded by this mRNA would be longer. -The protein coded by this mRNA would be the same size. -The protein coded by this mRNA would not form due to a failure in initiation. -The protein coded by this mRNA would kill the cell.
Eukaryotic cell. Eukaryotic mRNA code for proteins starts with an unformylated methionine whereas bacterial mRNA code for proteins starts with a formylated methionine
A particular mRNA makes a protein that has an unformylated methionine as its first amino acid. Did this mRNA come from a bacterial or a eukaryotic cell? -Bacterial cell. Bacterial mRNA code for proteins starts with an unformylated methionine whereas eukaryotic mRNA code for proteins starts with a formylated methionine. -Eukaryotic cell. Eukaryotic mRNA code for proteins starts with an unformylated methionine whereas bacterial mRNA code for proteins starts with a formylated methionine. -The cell cannot be determined, because both eukaryotic and bacterial mRNA code for proteins may start with a formylated or unformylate methionine. -Neither bacterial nor eukariotic cell, because no mRNA code for proteins starts with an unformylated methionine.
white
A plasmid contains a multiple cloning site inside the coding region of the lacZ gene and also contains an ampicillin resistance gene at a separate locus. When cells are transformed with a successfully recombinant plasmid containing a piece of DNA cloned into the multiple cloning site, what color will the colonies be when grown on an agar plate containing ampicillin and X-gal? green clear colonies will not grow white blue
3'-T-A-C-G-G-T-C-A-5'
A probe with the sequence 5'-A-T-G-C-C-A-G-T-3' will serve as a probe for which sequence? 3'-A-C-T-G-G-C-A-T-3' 3'-T-A-C-G-G-T-C-A-5' 3'-T-G-S-C-C-G-T-A-5' 3'-A-T-G-C-C-A-G-T-5'
1800
A protein is 300 amino acids long. Which of the following could be the number of total nucleotides in the section of DNA that codes for this protein? (Remember: DNA is double-stranded.) 1800 300 900 100 3
II, III, I
A researcher is studying the synthesis of a specific amino acid found in Neurospora. She knows that the pathway begins with a precursor that is converted into the amino acid with two known intermediates (Substance Blue and Substance Green). She accurately predicts that this amino acid synthesis pathway is catalyzed by three enzymes, (I, II, and III). She subsequently identifies three mutants that she calls Mutant I, Mutant II, and Mutant III. With the information about the mutants below place the enzymes in the order that the enzymes act in this pathway. (Note: the numbers I, II, and III don't necessarily indicate the order in which the enzymes appear.) Mutant I (only Enzyme I is mutated) is unable to synthesize the amino acid even if she provided the mutant with both Substance Blue and Substance Green. Mutant II (only Enzyme II is mutated) is able to synthesize the amino acid if she provided the mutant with Substance Blue or Substance Green. Mutant III (only Enzyme III is mutated) is able to make the amino acid if she provided the mutant with Substance Green, but not if she provided the mutant with only Substance Blue. I, II, III II, III, I III, II, I II, I, III III, I, II
defective reverse transcriptase
A scientist is troubleshooting the synthesis of a cDNA library. The scientist performs both a Northern and a Southern blot. The Northern blot demonstrated the presence of RNA while the Southern blot indicated that no cDNA was present in the sample. What is likely to be the cause of the failed synthesis of the cDNA library? temperature too cold for annealing proper primers too many dNTPs defective reverse transcriptase
size of the fragment
Agarose gels separate DNA fragments based on what property? amount of agarose in the DNA charge of the DNA molecule amount of adenine bases in the sequence size of the fragment
980,100
Albinism is an autosomal recessive trait in humans. Assume that there are 100 albinos (aa) in a population of 1 million. How many individuals would be expected to be homozygous normal (AA) under equilibrium conditions? 100 10,000 19,800 980,100 999,900
Polypeptides can be degraded and then reassembled to produce entirely different sequenced polypeptides.
All of the following are examples of posttranslational modifications, EXCEPT________. -Prosthetic groups, such as metals or vitamins, can be added. -The N-terminal amino acid is often removed or modified. -Polypeptide chains can be cleaved to produce a shorter and functional polypeptide. -Individual amino acid residues are sometimes modified, such as adding a phosphates, acetyl, or methyl groups can be added. -Polypeptides can be degraded and then reassembled to produce entirely different sequenced polypeptides.
rRNA Ribosomal RNA and ribosomes form the site of protein translation. Transfer RNAs work to bring amino acids to the ribosome. After a tRNA contributes its amino acid to the growing polypeptide chain, it must be "recharged" with a new amino acid. This is done independently of rRNA.
All of the following are involved in the process of tRNA charging EXCEPT __________. amino acids ATP aminoacyl tRNA synthetase rRNA
removal of introns Introns are removed from the mRNA posttranscriptionally in eukaryotes
All of the following may occur during posttranslational modification of a protein EXCEPT __________. -addition of metals to create tertiary or quaternary structures -addition of phosphate groups -removal of N-terminal amino acid -removal of introns
to be resistant to ampicillin
All the colonies growing in the petri dish after transformation have been selected to: -to be resistant to ampicillin -to contain the gene of interest -they are normal bacterial cells and have not been selected yet.
There will be glycines at all glycine positions and at all valine positions. Rationale Because the t R N AValine will still recognize the valine codon, it will attach whatever amino acid it has been charged with. Due to the mutation, it is now charged with glycine, so that will be inserted instead of valine. However, the glycine codons will still be recognized by their t R N AGlycine and will still place glycines at these "normal" positions.
An aminoacyl t RNA synthase Valine is mutated so that it now attaches the amino acid glycine to the t RNA Valine instead of valine. What will happen at translation? -There will be glycines at all valine positions and valines at all glycine positions. -There will be valines at all glycine positions and glycines at all valine positions. -There will be glycines at all glycine positions and at all valine positions. -There will be valines at all glycine positions and at all valine positions. -There will be no translation.
RNA that is removed during RNA processing
An intron is a section of ________. -transfer RNA that binds to the anticodon -carbohydrate that serves as a signal for RNA transport -protein that is clipped out posttranslationally -DNA that is removed during DNA processing -RNA that is removed during RNA processing
template strand in both bacteria and eukaryotes
An mRNA that is being produced comes off of the ________. -template strand in both bacteria and eukaryotes -coding strand in bacteria and the template strand in eukaryotes -coding or template strand in both bacteria and eukaryotes depending upon the species -coding strand in both bacteria and eukaryotes -template strand in bacteria and the coding strand in eukaryotes
inherited factors control metabolic activities
Archibald Garrod's work suggested that _____. -DNA is the genetic material -inherited factors control metabolic activities -each gene codes for a unique ribosome -each gene is associated with the production of a single polypeptide -biologically active D N A is in a double-helical structure
Adding a base early in the coding region would change more amino acids since an addition or deletion of a base pair would change every codon after the addition or deletion.
Assume that a base addition occurs early in the coding region of a gene. Is the protein product of this gene expected to have MORE or FEWER altered amino acids compared with the original gene with a base deletion late in the coding region? -Adding a base early in the coding region would change fewer amino acids since only a deletion of a base pair would change every codon following the deletion. -Adding a base early in the coding region would change more amino acids since only an addition of a base pair would change every codon following the addition. -Adding a base early in the coding region would change more amino acids since an addition or deletion of a base pair would change every codon after the addition or deletion. -Adding a base early in the coding region would change fewer amino acids since an addition of a base pair has less impact on amino acid sequence than a deletion does.
300, 600, 700, 1200
Assume that a plasmid (circular) is 2800 base pairs in length and has restriction sites for EcoRI at the following locations: 400, 700, 1400, and 2600. Give the expected sizes of the restriction fragments following complete digestion with EcoRI. 300, 600, 700, 1200 200, 400, 700, 1200 300, 700, 2200 700, 400, 1400, 2600 400, 1200, 1600
42%
Assume that a trait is caused by the homozygous state of a gene that is recessive and autosomal. Nine percent of the individuals in a given population express the phenotype caused by this gene. What percentage of the individuals would be heterozygous for the gene? Assume that the population is in Hardy-Weinberg equilibrium. 91% 9% 58% 42%
49%
Assume that in a Hardy-Weinberg population, 9% of the individuals are of the homozygous recessive phenotype. What percentage are homozygous dominant? 51% 91% 49% 9%
20^250
Assuming that an amino acid sequence is 250 amino acids long, how many different molecules, each with a unique sequence, could be formed? 250^20 250 × 20 250 × 20 × 2 20^250
0.42
Assuming that p = 0.3 for a population in Hardy-Weinberg equilibrium, what would be the expected frequency of heterozygotes for the involved allelic pair? 0.42 0.58 0.7 0.31
It will change the reading frame.
Assuming the genetic code is a triplet, what effect would the addition or loss of two nucleotides have on the reading frame? -It will have no effect on the reading frame, but will result in the addition or loss of amino acids in the resulting protein. -It will have no effect on the reading frame. -It will change the reading frame. -It will change the reading frame and result in the addition or loss of amino acids in the resulting protein.
P site
At which site does the charged initiator tRNA bind during protein synthesis? T site P site A site E site
3′ TCTTAAG 5′ This sequence does not contain the BamHI recognition site.
BamHI cuts the sequence 5′ G|GATCC 3′. Which of the following sequences would not be recognized by this enzyme? 5′ AGGATCCGTA 3′ 3′ CCTAGGATC 5′ 5′ AGCGGATCC 3′ 3′ TCTTAAG 5′
the role of a specific gene is to produce a specific enzyme
By their experimentation using the Neurospora fungus, Beadle and Tatum were able to propose the far-reaching hypothesis that ________. -genetic recombination occurred in Neurospora -several different enzymes may be involved in the same step in a biochemical pathway -more than one codon can specify a given amino acid -prototrophs will grow only if provided with nutritional supplements -the role of a specific gene is to produce a specific enzyme
The process of splitting a genetically homogeneous population into two or more populations that undergo genetic differentiation and eventual reproductive isolation.
Choose a general definition for the term speciation. -The process of genetic information flow that occurs when individuals move between populations. -The process of evolutionary change within populations of a species when a large population undergoes a drastic but temporary reduction in numbers. -The process of significant random fluctuations in allele frequencies that occurs over time within a population. -The process of splitting a genetically homogeneous population into two or more populations that undergo genetic differentiation and eventual reproductive isolation.
important function for that sequence
Conservation of amino acid sequence among distantly related groups of organisms is suggestive of a(n) ________. -lack of common ancestor -lack of selective pressure on that sequence -intrinsic resistance to mutations in that sequence -important function for that sequence
Away from the water environment and in the interior portion of the molecule.
Considering the types of side chains on amino acids and their relationship to protein structure, where are the amino acids with hydrophobic side chains most likely to be located? -Closer to the water environment and in the exterior portion of the molecule. -Hydrophobic side chains will alternate with hydrophilic side chains. The hydrophilic side chains will hide the hydrophobic side chains from the water environment. -Away from the water environment and in the interior portion of the molecule. -Hydrophobic side chains will form a hydrophobic cluster folding the protein in a single globule.
Pribnow Box Rationale The Goldberg-Hogness box, or TATA box, is found in the core promoter of eukaryotes and is the site of transcription initiation by R N A polymerase. The Pribnow box (which also contains a "TATA" sequence) is the site of transcription initiation in prokaryotes.
Considering transcription initiation, the core promoter in eukaryotes is homologous to what in prokaryotes? rho Sigma 70 core enzyme Pribnow Box Goldberg-Hogness box
protein folding
Creutzfeldt-Jakob, Huntington, Alzheimer, and Parkinson disease are all characterized with which part of protein synthesis? N-terminal modification protein folding termination elongation initiation
It serves a vital function; therefore, any changes in amino acid sequence are usually strongly selected against.
Cytochrome c is a respiratory pigment found in the mitochondria of eukaryotes. Compared with some other proteins, it has changed very slowly over long periods of time. Why? -It serves a vital function; therefore, any changes in amino acid sequence are usually strongly selected against. -It serves a vital function; therefore, any changes in amino acid sequence are usually low selected against. -It serves a minor function; therefore, any changes in amino acid sequence are usually strongly selected against. -It serves a minor function; therefore, any changes in amino acid sequence are usually low selected against.
sticky and blunt ends
DNA fragments cut by restriction enzymes can form two types of ends. What are these ends called? ligase and blunt ends sticky and blunt ends tails and heads salvage and sharp ends
reconnects the phosphodiester linkage between bases on the same strand of DNA
DNA ligase ________. -adds bases into a growing DNA molecule -removes bases from a DNA molecule -reconnects the phosphodiester linkage between bases on the same strand of DNA -reconnects the bases together between the DNA strands -cuts the DNA to produce sticky or blunt ends
Dideoxynucleotides ddNTPs are nucleotide analogs that cause chain termination due to lack of a free 3'-hydroxyl group.
DNA sequencing by the Sanger method employs which of the following for chain termination? Ribonucleotides Dideoxynucleotides Dinucleotides Deoxynucleotides
Fitness is a measure of the proportion of offspring that a particular phenotype will contribute to the next generation.
Define the term fitness. -Fitness is a measure of the neutral alleles in the genotype of a population. -Fitness is a measure of the genetic information carried by members of a population. -Fitness is a measure of the proportion of offspring that a particular phenotype will contribute to the next generation. -Fitness is a measure of the patterns of genetic variation within and among groups of interbreeding individuals.
third nucleotide of the codon
Due to the wobble hypothesis, which position in the codon, if changed to a different nucleotide, would be least likely to cause a change in the amino acid encoded? any nucleotide of the codon. first nucleotide of the codon second nucleotide of the codon third nucleotide of the codon Either the first or second nucleotide of the codon.
is oriented by its Shine-Delgarno sequence through base-pairing with an r RNA
During bacterial translation initiation, the m R N A _____. -requires A T P hydrolysis for binding to the ribosomal subunit -binds to the large subunit -is oriented so that the A U G start codon is in the A site -only binds f-met t R N A after the entire ribosome has been assembled -is oriented by its Shine-Delgarno sequence through base-pairing with an r RNA
7-methylguanosine (m7G) cap
During eukaryotic translation initiation, the _____ serves a role analogous to the Shine-Delgarno sequence in bacteria. 7-methylguanosine (m7G) cap Poly-A tail Initiator TATA box
IF3
During initiation in bacterial translation, a particular mutation causes the premature binding of the large ribosome subunit to the small ribosome subunit. Which component of initiation is not working properly? Ribosome's E site IF1 IF2 Shine-Dalgarno sequence on the mRNA IF3
A site
During the elongation phase of translation, charged t R N A s enter the ribosome at the ______. A site P site E site Shine- Delgarno site
requires the uncoiling of the chromatin fiber
Eukaryotic transcription is different than bacterial transcription because eukaryotic transcription ________. -only requires one RNA polymerase -occurs in the cytoplasm -does not require the mRNA to be modified -requires the uncoiling of the chromatin fiber -does not require general transcription factors to initiate transcription
a.Blotting is not used in FISH.
Fluorescence in situ hybridization is another way to visualize the presence of a nucleotide sequence. Which of the following is an advantage of FISH over Northern and Southern blots? a.Blotting is not used in FISH. b.Probes are not needed in FISH. c.There are no advantages to FISH over Northern and Southern blots. d.Fluorophores are not used in Northern or Southern blots.
mutations
Genetic drift arises from all the following EXCEPT ________. a genetic bottleneck a founder effect mutations a small breeding population
very small
Genetic drift is primarily associated with what size breeding populations? very small very large mid-sized Genetic drift has the same effect on all population sizes.
fluorescently tagged ddNTPs
High throughput sequencing takes advantage of automated reading of sequencing data. Which of the following assists in automating the sequencing readout? radioactive ddNTPs fluorescently tagged ddNTPs radioactive dNTPs fluorescently tagged dNTPs
Because it allows bacteria to store memories of viral infections
How is CRISPR an "adaptive" immune system? -Because it allows us to use a bacteria system for gene editing in humans -Because it allows bacteria to store memories of viral infections -Because it allows the bacteria to destroy viruses.
61 There are 61 codons that code for amino acids and three stop codons that do not code for an amino acid.
How many different codons code for amino acids? 64 3 61 20
the plant was edited so that the pores close on the bottom of the leaves, thus letting out less water.
How was the gene-edited crop in the film able to better withstand drought conditions? -the plant was edited so it could have a higher protein content -the plant was edited so it could increase its photosynthetic capability -the plant was edited so that it can be resistant to insects -the plant was edited so that the pores close on the bottom of the leaves, thus letting out less water.
In eukaryotes, three polymerases (I, II, and III) have been identified; only one has been described in prokaryotes.
Identify a difference between the RNA polymerases of eukaryotes and prokaryotes. -In prokaryotes, three polymerases (I, II, and III) have been identified; only one has been described in eukaryotes. -In eukaryotes, three polymerases (I, II, and III) have been identified; only one has been described in prokaryotes. -In prokaryotes, three polymerases (α, β, and δ) have been identified; only one has been described in eukaryotes. -In eukaryotes, three polymerases (α, β, and δ) have been identified; only one has been described in prokaryotes.
Southern Blot
If I am looking for a specific DNA sequence in a genome I should use: Southern Blot Northern Blot Western Blot FISH
FISH
If I want to locate a specific DNA sequence in a tissue, I should use: Southern Blot Northern Blot Western Blot FISH
25
If humans had 25 amino acids instead of 20 amino acids then how many aminoacyl tRNA synthetases would humans have? 75 20 25 4 3
exons; introns
If one compares the base sequences of related genes from different species, one is likely to find that corresponding ________ are usually conserved, but the sequences of ________ are much less well conserved. introns; chaperons introns; proteins exons; introns chaperons; exons introns; exons
The endonuclease identifies its specific recognition sequence.
If one wishes to clone a gene using typical restriction endonucleases, how does the restriction endonuclease identify the appropriate cut sites in the genome? -The endonuclease cuts randomly in the genome. -The endonuclease recognizes the gene of interest. -The endonuclease cannot identify the cut sites. -The endonuclease identifies its specific recognition sequence.
two bases Rationale Using six bases in a two-base codon would yield 62 = 36 different combinations. That would be more than enough to encode all 20 amino acids and the stops.
If there were six bases in D N A and still only 20 amino acids, how long would a codon need to be in order to specify an amino acid? Two bases Three bases Four bases Six bases 20 bases
charged tRNA, RNA triplet, and ribosome
In 1964, Nirenberg and Leder used the triplet binding assay to determine specific codon assignments. A complex of which of the following components was trapped in the nitrocellulose filter? charged tRNA, RNA triplet, and ribosome ribosomes and DNA uncharged tRNAs and ribosomes sense and antisense strands of DNA free tRNAs
cars
In Chapter 3 of the film (The Gene Machine) CRISPR is compared to another technological advance regarding the fact that is also a first technology. PCR airplanes IVF Correct! cars
−35 sequence (TTGACA) Pribnow box (TATAAT)
In a particular bacterial mutant, a specific gene is not producing a mRNA or the corresponding protein. Researchers sequence the gene and determine that there are no mutations in the coding portion of the gene. Choose the structures that could be mutated to explain these observations. Select all that apply. −35 sequence (TTGACA) Pribnow box (TATAAT) termination sequences splice sites poly-A tail
M = 0.6; m = 0.4
In a population of 10,000 individuals, where 3600 are MM, 1600 are Mm, and 4800 are mm, what are the frequencies of the M alleles and the m alleles? M = 0.3; m = 0.7 M = 0.4; m = 0.6 M = 0.7; m = 0.3 M = 0.6; m = 0.4
42%
In a population of 100 individuals, 49% are of the NN blood type. What percentage is expected to be MN assuming Hardy-Weinberg equilibrium conditions? 42% 21% 51% 9% There is insufficient information to answer this question.
a formyl group is attached to the initiating methionine
In bacteria, the methionine that initiates the formation of a polypeptide chain differs from subsequently added methionines in that _______. -the initiating methionine is not an amino acid -incorporation of the initial methionine does not require a tRNA -its tRNA anticodon is not complementary to the AUG codon -a formyl group is attached to the initiating methionine
true
In eukaryotic cells, transcription occurs in the nucleus, and translation occurs in the cytoplasm. True False
Presence of introns in D N A Rationale Introns make up the bulk of the phenylalanine hydroxylase gene in humans. After transcription, the introns are removed and the exons spliced together.
In humans, the phenylalanine hydroxylase gene is 90,000 (90 k b) bases long, yet the m R N A is only 2,400 (2.4 k b). What explains this difference? -R N A editing -Removal of exons in the final m R N A -Loss of stability without a 5′ cap -Presence of introns in D N A -Code for poly A tail that is removed in m R N A
sigma subunit
In prokaryotes, which component must disassociate to allow for elongation of the transcriptional complex? sigma subunit RNA polymerase rho none of the above
genetic drift
In small isolated populations, gene frequencies can fluctuate considerably. The term that applies to this circumstance is ________. genetic isolation genetic drift natural selection allelic separation stabilizing selection
e.to allow D N A polymerase to synthesize D N A Rationale The D N A polymerase used in P C R is most commonly from the bacterium Thermus aquaticus. T. aquaticus was first discovered living in the hot springs of Yellowstone National Park. Between 70°Celsius and 75°Celsius is the optimal temperature for the heat-stable Taq polymerase to synthesize D N A.
In the polymerase chain reaction, the purpose of the step in which the temperature is between 70°Celsius and 75°Celsius is _____. a.to denature the D N A b.to denature the polymerase c.to allow the primers to anneal d.to allow the primers to release from the template e.to allow D N A polymerase to synthesize D N A
Secondary, tertiary, and quaternary
In this drawing of hemoglobin, what level(s) of structure are visible? Primary Secondary Tertiary Quaternary Secondary, tertiary, and quaternary
higher mortality rates higher frequency of aberrant phenotypes
In zoo animals, inbreeding often occurs because of a lack of a sufficient pool of breeding individuals. Under such conditions, what two characteristics are often exhibited among inbred organisms? Select the two characteristics. lower level of inbreeding higher mortality rates higher fitness higher frequency of aberrant phenotypes higher proportion of heterozygotes higher rates of reproductive success
Both phenylalanine and tyrosine can be obtained from the diet.
Individuals with phenylketonuria cannot convert phenylalanine to tyrosine. Why don't these individuals exhibit a deficiency of tyrosine? -Tyrosine is a nonessential amino acid. -Both phenylalanine and tyrosine are nonessential amino acids. -Both phenylalanine and tyrosine can be obtained from the diet. -Phenylalanine and tyrosine are needed in only small amounts.
The introns have been spliced out during mRNA processing.
It has been recently determined that the gene for Duchenne muscular dystrophy (DMD) is more than 2000 kb (kilobases) in length; however, the mRNA produced by this gene is only about 14 kb long. What is a likely cause of this discrepancy? -When the mRNA is produced, it is highly folded and therefore less long. -The exons have been spliced out during mRNA processing. -There are more amino acids coded for by the DNA than by the mRNA. -The introns have been spliced out during mRNA processing. -The DNA represents a double-stranded structure, whereas the RNA is single-stranded.
protein domains
Modular portions of a protein that fold into stable conformations with specific functional capabilities are referred to as ________. protein subunits protein chaperones protein secondary structures protein domains protein quaternary structures
natural selection
Mutation and migration introduce new alleles into populations. What is the most likely principal force that will shift allelic frequencies within large populations? directional selection natural selection disruptive selection stabilizing selection
b)RNA
Northern blots are used to study what type of molecule? a)Proteins b)RNA c)DNA d)RNA and proteins
ribonucleic acids
Nucleic acid blotting is commonly used in molecular biology. Northern blotting is used to detect the presence of which type of nucleic acid? deoxyribonucleic acids transfer ribonucleic acids ribonucleic acids triphosphate nucleic acids unnatural nucleic acids
The substance needs to be added after the metabolic block in the biochemical pathway.
Nutritional mutants in Neurospora can be "cured" by treating the medium with substances in the defective metabolic pathway. What determines whether the mutant strain (auxotroph) is "cured" by a particular substance? -The substance needs to be added before the metabolic block in the biochemical pathway. -The substance to be added depends on other substances in the media. -The substance needs to be added after the metabolic block in the biochemical pathway. -The first substance in the biochemical pathway needs to be added.
the bacterial cells do carry the engineered plasmid but not the insert (gene of interest)
Obtaining blue bacterial colonies after transformation means: -the bacterial cells do not carry the engineered plasmid -the bacterial cells do carry the engineered plasmid but not the insert (gene of interest) -the bacterial cells do carry the engineered plasmid with the insert
A Site, P Site, E Site
Once elongation is underway, tRNAs involved in the process occupy a series of sites on the complexed ribosome. The occupation of sites occurs in the following order. A Site, S Site, E Site A Site, P Site, E Site P Site, E Site, A Site A Site, P Site, E Site, S Site
True Advances in DNA amplification, sequencing, and computer analysis of large databases have made it possible to extract, sequence, and analyze genetic similarities and differences between living and extinct species of both humans and animals.
Paleogenomics is based on the recovery and sequencing of DNA from fossil remains of extinct species. True False
True
Phage λ can carry larger DNA fragments than plasmids. True False
recognize and digest foreign DNA
Protospacer adjacent motifs, PAMs, allow bacteria to do which of the following? -recognize and digest foreign DNA -recognize and integrate foreign DNA -recognize proper spacing for bacterial transcription initiation -recognize and digest their own DNA
Changes to the m R N A sequence after transcription Rationale Insertion/deletion editing adds or subtracts from the total number of bases in the m R N A. This occurs after transcription and changes the message meaning.
R N A editing can be the result of insertion/deletion editing. This results in _______________. -Removal of introns after transcription -Addition (and subsequent removal) of poly-A tail as part of regulation of expression -Removal of T's added to m R N A by mistake and replacement with U's -Changes to the m R N A sequence after transcription -Switching one base for another
third
Reading the RNA sequences in a 5' to 3' direction, a base at the first position of an anticodon on the tRNA would pair with a base at the ________ position of the mRNA. third second first
palindromic sequence
Recognition sequences for restriction enzymes possess the unique quality of being the same when read 5 to 3 on either strand. What is this property called? palindromic sequence recombination sequence origin sequence consensus sequence gene sequence
False Restriction endonucleases cut DNA at specific sequences, but DNA ligase must be used to bond two strands covalently with the same "sticky ends."
Restriction endonucleases cut DNA at specific recognition sequences and then bond two strands covalently with the same "sticky ends." True False
PCR
Restriction enzymes are used in all of the following molecular biology techniques EXCEPT __________. mapping studies creating DNA libraries cloning DNA into vectors PCR
The number of sites and distance between them for the specific restriction enzyme.
Restriction mapping is used to characterize cloned DNA. What does a restriction map tell the researcher about the cloned DNA? -The size of the genome the cloned DNA was isolated from. -The number of sites and distance between them for the specific restriction enzyme. -The distances between restriction sites for the specific restriction enzyme. -The restricted conditions under which the organism can grow. -The number of restriction sites for the specific restriction enzyme.
They do not have a 3 hydroxyl, which does not allow the extension of the polynucleotide.
Sanger sequencing is based on the order in which ddNTPs are added to a growing polynucleotide. Why are ddNTPs integral to the Sanger sequencing method? -They do not have a 2 hydroxyl, which does not allow the extension of the polynucleotide. -They have a 3 hydroxyl that allows for extension of the polynucleotide. -They do not have a 3 hydroxyl, which does not allow the extension of the polynucleotide. -They have a 2 hydroxyl that allows for extension of the polynucleotide.
ddNTPs
Sanger sequencing method's key component was: ddNTPs dNTPs Mg DNA polymerase Primer DNA template
stabilizing selection
Selection that favors the middle phenotype and selects against the extreme phenotypes is said to be ________. diselection disruptive selection stabilizing selection directional selection
All of them The fact that there is a point mutation in the globin B gene will change the sequence of amino acids (primary structure) and this will affect this protein all the way to the quaternary structure.
Sickle cell anemia affects the following protein structure: Primary Secondary Tertiary Quaternary All of them
This change would be predicted to have less effect compared to the change of the amino acid from glutamic acid to valine.
Sickle-cell anemia is caused by a mutation that changes the second nucleotide of the codon from GAG to GUG. This results in a change of the amino acid from glutamic acid to valine. If the mutation affected the third nucleotide of the codon and changed GAG to GAU then the amino acid would change from a glutamic acid to aspartic acid. Would you predict this change to have the same effect? -This change would be predicted to have less effect compared to the change of the amino acid from glutamic acid to valine. -This change would be predicted to have more effect compared to the change of the amino acid from glutamic acid to valine. -This change would be predicted to have the same effect compared to the change of the amino acid from glutamic acid to valine. -It is impossible to predict the effect of a single nucleotide without proper genetic sequencing.
this nucleotide can form hydrogen bonds with more than one nucleotide
So, the advantage of having inosinic acid in tRNA is connected to the fact that: -this nucleotide forms a ester bond with the codon in mRNA -this nucleotide can form hydrogen bonds with more than one nucleotide
cis-acting elements
So, the consensus sequences in E. coli's promoter are: cis-acting elements transacting elements
Both cases involve the removal of an NH2 group.
Substitution RNA editing is known to involve either C-to-U or A-to-I conversions. What common chemical event accounts for each? -Both cases involve the removal of an OH group. -Both cases involve the removal of one group, but in one case it is an NH2 group, and in other - an OH group. -Both cases involve the removal of an NH2 group.
1/216
Suppose that in the use of polynucleotide phosphorylase, nucleotides A and C are added in a ratio of 1A:5C. What is the probability that an AAA sequence will occur? 1/125 1/432 1/216 1/36 1/64 1/27
bacterial defense against viral infection
The CRISPR-Cas system of gene editing is based on what naturally occurring biological process? viral defense against eukaryotic defenses bacterial defense against viral infection viral defense against bacterial defenses eukaryotic defense against viral infection
false
The Shine-Dalgarno sequence is important for the binding of the eurkaryotic ribosome to the mRNA sequence: True False
Overlapping reading frames Multiple translation initiation points allow a single mRNA to code for more than one protein
The chromosome of phage φX174 encodes nine proteins consisting of a total of more than 2300 amino acids, even though the size of its genome predicts that it should be able to code for only 1795 amino acids. The reason for this discrepancy is Overlapping reading frames Enhancers Frameshift mutations Alternative splicing
glycine (gly)
The experiments that deciphered the genetic code used an enzyme called polynucleotide phosphorylase. If researchers added this enzyme to a large quantity of only guanine (G) ribonucleoside diphosphates then a RNA molecule would be produced that would code for which amino acid? phenylalanine (phe) proline (pro) arginine (arg) lysine (lys) glycine (gly)
The genetic code is nonoverlapping.
The finding that some phage genes have multiple initiation sites is evidence against what characteristic of the genetic code? The genetic code is unambiguous. The genetic code is a triplet code. The genetic code is nonoverlapping. The genetic code is commaless. The genetic code is universal.
iii, iv, i, ii
The following are four processes common to most cloning experiments: i) transforming bacteria ii) plating bacteria on selective medium iii) cutting DNA with restriction endonucleases iv) ligating DNA fragments Place the components of this list in the order in which they would most likely occur during a cloning experiment. i, ii, iii, iv ii, iii, i, iv iv, i, iii, ii ii, i, iv, iii iii, iv, i, ii
Alternative Splicing
The following enables different mature mRNAs to be produced from the same RNA and therefore different proteins will be coded: Alternative Splicing Exon Shufling MicroRNAs
Individuals with a deletion in the CCR5 gene
The following individuals do not get infected with the HIV virus -Individuals with a perfect sequence for the CCR5 protein -Individuals with an insertion in the CCR5 gene -Individuals with a deletion in the CCR5 gene
c)Extract DNA, digest DNA with restriction enzymes, run a gel, transfer DNA fragments to membrane via blotting, hybridize membrane with probe, expose membrane to X ray film, develop Xray and observe band patterns
The following is the order of steps when preparing a Southern Blot: a)Extract DNA, transfer DNA fragments to membrane via blotting, hybridize membrane with probe, expose membrane to X ray film, develop Xray and observe band patterns b)Extract DNA, digest DNA with restriction enzymes, transfer DNA fragments to membrane via blotting, run a gel, hybridize gel with probe, expose gel to X ray film, develop Xray and observe band patterns c)Extract DNA, digest DNA with restriction enzymes, run a gel, transfer DNA fragments to membrane via blotting, hybridize membrane with probe, expose membrane to X ray film, develop Xray and observe band patterns d)Extract DNA, run a gel, hybridize membrane with probe, expose membrane to X ray film, develop Xray and observe band patterns
all used a cell free ("in vitro") system to synthesize proteins
The following is what the described experiments (Nurenberg & Matthaei, Nuremberg & Leder) had in common: -all used cellulose filters to retain radioactive ribosomes -all used a cell free ("in vitro") system to synthesize proteins -all used homopolymers -all used heteropolymers
knowledge of the sequence product
The generation of a knock-out organism generally requires all the following EXCEPT ________. embryonic stem cells a selectable marker a targeting vector knowledge of the sequence product knowledge of the target sequence
degenerate Rationale Degeneracy is the term for redundancy in the genetic code; 61 codons code for 20 amino acids. As a result, many amino acids have more than one codon.
The genetic code is _________, meaning that an amino acid may be encoded by more than one codon. unambiguous degenerate commaless universal nonoverlapping
universal
The genetic code is fairly consistent among all organisms. The term often used to describe such consistency in the code is ________. exceptional overlapping trans-specific universal none of the above
whole-genome sequencing
The genomics era began with the development of which of the following? PCR whole-transcriptome sequencing third-generation sequencing whole-genome sequencing
human mitochondrial genetic code
The nuclear genetic code is considered universal with a few exceptions. Some of these exceptions are found when comparing the nuclear genetic code of humans to what? human mitochondrial genetic code acterial genetic code angiosperm's genetic code phage M2 genetic code chimpanzee's genetic code
all of the above Rationale A string of many adenine residues is added posttranscriptionally to the 3′ end of most eukaryotic m R N As. The primary functions are to help termination of transcription and stabilize m R N As against degradation by exonucleases.
The poly(A) tail of m R N A _____. -is added to the 3′ end of most eukaryotic m R N As -is found on most mature eukaryotic m R N As -helps terminate transcription -helps prevent degradation of eukaryotic m R N As -All of the above are correct.
the sequence of amino acids
The primary structure of a protein is determined by ________. -a series of helical domains -pleated sheets -covalent bonds formed between fibroin residues -the sequence of amino acids -hydrogen bonds formed between the components of the peptide linkage
succinate
The problem below relates to the synthesis of several intermediates in the citric acid cycle, which is essential in the production of ATP through aerobic respiration. A set of experimental results relating the growth (+) of Neurospora on several media is given in the table. Based on the information provided, present the biochemical pathway for the substances oxaloacetate, fumarate, malate, and succinate, and the locations of the metabolic blocks produced by the various strains. Strains: 1. MM 2. MM+oxaloacetate 3. MM+fumarate 4. MM+malate 5. MM+succinate 1. 2. 3. 4. 5. 162 - + - + - 136 - + - - - 141 - + + + - MM = minimal medium What is the first molecule in the biochemical pathway? succinate malate oxaloacetate fumarate
oxaloacetate
The problem below relates to the synthesis of several intermediates in the citric acid cycle, which is essential in the production of ATP through aerobic respiration. A set of experimental results relating the growth (+) of Neurospora on several media is given in the table. Based on the information provided, present the biochemical pathway for the substances oxaloacetate, fumarate, malate, and succinate, and the locations of the metabolic blocks produced by the various strains. Strains: 1. MM 2. MM+oxaloacetate 3. MM+fumarate 4. MM+malate 5. MM+succinate 1. 2. 3. 4. 5. 162 - + - + - 136 - + - - - 141 - + + + - MM = minimal medium What is the last molecule in the biochemical pathway? fumarate oxaloacetate succinate malate
141, 162,136
The problem below relates to the synthesis of several intermediates in the citric acid cycle, which is essential in the production of ATP through aerobic respiration. A set of experimental results relating the growth (+) of Neurospora on several media is given in the table. Based on the information provided, present the biochemical pathway for the substances oxaloacetate, fumarate, malate, and succinate, and the locations of the metabolic blocks produced by the various strains. Strains: 1. MM 2. MM+oxaloacetate 3. MM+fumarate 4. MM+malate 5. MM+succinate 1. 2. 3. 4. 5. 162 - + - + - 136 - + - - - 141 - + + + - MM = minimal medium What is the order of mutations? 136, 141, 162 162, 141, 136 162, 136, 141 141, 162,136 136, 162, 141 141, 136, 162
succinate, fumarate, malate, oxaloacetate
The problem below relates to the synthesis of several intermediates in the citric acid cycle, which is essential in the production of ATP through aerobic respiration. A set of experimental results relating the growth (+) of Neurospora on several media is given in the table. Based on the information provided, present the biochemical pathway for the substances oxaloacetate, fumarate, malate, and succinate, and the locations of the metabolic blocks produced by the various strains. Strains: 1. MM 2. MM+oxaloacetate 3. MM+fumarate 4. MM+malate 5. MM+succinate 1. 2. 3. 4. 5. 162 - + - + - 136 - + - - - 141 - + + + - MM = minimal medium What is the proper order of molecules in this biochemical pathway? succinate, malate, fumarate, oxaloacetate succinate, fumarate, malate, oxaloacetate
binds to a bacterial gene's promoter Rationale Sigma is a polypeptide subunit of R N A polymerase that binds to the −10 and −35 region of the promoter, putting the catalytic center of the enzyme in contact with the transcription initiation site of the gene.
The sigma subunit of bacterial R N A polymerase _____. -binds to a bacterial gene's promoter -is composed of both polypeptide and R N A molecules -is required for R N A polymerization -is required for termination of transcription -is required for ribosomal binding
False The annealing phase takes place at the lowest temperature of PCR. Taq polymerase is derived from bacteria that live in hot springs, so the enzyme is thermostable, meaning that its enzymatic properties can withstand the high temperatures needed for denaturation.
The thermostability of Taq polymerase is required during the annealing phase of PCR. True False
RNA editing
The type of RNA modification that requires guide RNAs is ________. -removal of introns -addition of the 3 polyadenylated tail -addition of the 7-methylguanosine cap to the 5 end -RNA editing -splicing together of exons
may differ at the third position Rationale The wobble hypothesis suggests that pairing may be less stringent at the third position (3′) of the codon. Because of the degeneracy of the codons, this allows the same t R N A molecule to pair with two or more codons that are identical at the first two codon positions.
The wobble hypothesis predicts that codons coding for the same amino acid _____. may differ at the first position may differ at the second position may differ at the third position may differ at the first two positions may differ at all three positions
valine instead of glutamic acid in the sixth position
The β chain of adult hemoglobin is composed of 146 amino acids of a known sequence. In comparing the normal β chain with the β chain in sickle cell hemoglobin, what alteration is one likely to find? -frameshift substitutions -glutamic acid replacing valine in the first position -valine instead of glutamic acid in the sixth position -trinucleotide repeats -extensive amino acid substitutions
yeast artificial chromosome
There are multiple cloning vector types in modern recombinant DNA technology ranging from plasmids to viral vectors. Which vector type is most useful when cloning an insert of approximately 500kb? yeast artificial chromosome viral vector bacterial plasmid human artificial chromosome bacterial artificial chromosome
Stabilizing Selection
This is thought to be the most common mechanism of action for natural selection because most traits do not appear to change drastically over time. Directional Selection Stabilizing Selection Disruptive Selection
cDNA libraries
To study gene expression, scientists use to build: Genomic libraries cDNA libraries
the use of calcium and brief exposure to elevated temperature
Transformation of cells using the technique of heat shock requires which of the following? -brief exposure to elevated temperature -the use of zinc ions -brief electric shock -the use of calcium and brief exposure to elevated temperature -the use of calcium ions
complementary base pairing between mRNA and DNA
Translation in bacteria is directly dependent on all of the following associations except _______. -complementary base pairing between mRNA and tRNA -complementary base pairing between mRNA and rRNA -complementary base pairing between mRNA and DNA -association of the 30S and the 50S ribosomal subunits
Eukaryotes use the 5 G-cap and Poly-A-tail on their mRNAs to initiate translation.
Translation in bacterial and eukaryotic cells has many similarities, but there are also several key differences. Which of the following is one of those differences that is seen in eukaryotes? -Eukaryotic ribosomes are smaller with fewer proteins and RNA molecules. -Eukaryotes only require one release factor that recognizes all three stop codons. -Eukartyotic mRNA contains a ShineDalgarno sequence that increases the efficiency of translation. -Eukaryotes use the 5 G-cap and Poly-A-tail on their mRNAs to initiate translation. -Translation and transcription are coupled.
it is maternally inherited
Using mitochondrial genome to study the evolution of populations is easier because: -it is a smaller genome -it is maternally inherited -its genes provide our energy and this is prerequisite for evolution
b. adding a polyadenylation tail to the 3′ end c. RNA editing d. adding a modified guanine to the 5′ end f. splicing of introns
What are four ways that mRNA can be modified? Select the four сorrect answers. a. adding a modified guanine to the 3′ end b. adding a polyadenylation tail to the 3′ end c. RNA editing d. adding a modified guanine to the 5′ end e. adding a polyadenylation tail to the 5′ end f. splicing of introns
diagrammatic representations of evolutionary relationships among organisms
What are phylogenetic trees? -diagrammatic representations of relationships between allele frequencies among organisms -diagrammatic representations of mutation relationships among organisms -diagrammatic representations of evolutionary relationships among organisms -diagrammatic representations of relationships between genotype frequencies among organisms
For a given allele, inbreeding increases the proportion of homozygotes in a population.
What are the genetic consequences of inbreeding? -For a given allele, inbreeding increases the proportion of heterozygotes in a population. -For a given allele, inbreeding increases the proportion of males and females in a population. -For a given allele, inbreeding increases the proportion of homozygotes in a population. -For a given allele, inbreeding increases the proportion of genotypes in a population.
it was ethically defensible
What did the National Academy of Sciences conclude about the permissibility of genetically altering human embryos for the purpose of producing a child? -it was ethically defensible -it was intrinsically evil -it is ready to be implemented
expected frequency of heterozygotes in a population in the Hardy−Weinberg equilibrium
What does the variable 2pq represent? -expected frequency of male and female individuals in a population in the Hardy−Weinberg equilibrium -expected frequency of relevant individual alleles in a population in the Hardy−Weinberg equilibrium -expected frequency of heterozygotes in a population in the Hardy−Weinberg equilibrium -expected frequency of heritable traits in a population in the Hardy−Weinberg equilibrium
It will have no effect on the reading frame, but will result in the addition or loss of amino acids in the resulting protein.
What effect would the addition or loss of three, six, or nine nucleotides have on the reading frame? -It will change the reading frame. -It will have no effect on the reading frame, but will result in the addition or loss of amino acids in the resulting protein. -It will have no effect on the reading frame. -It will change the reading frame and result in the addition or loss of amino acids in the resulting protein.
mRNA shifts in the 5' direction along the ribosome.
What event occurs during translocation? -The two ribosomal subunits join to form a complex. -Amino acids are added to the polypeptide chain. -The polypeptide is cleaved from the terminal tRNA. -mRNA shifts in the 5' direction along the ribosome.
a DNA or an RNA molecule used in hybridization reactions A probe is a labeled single strand of DNA or RNA used to locate its complementary sequence. Probes are commonly used in Southern and Northern blots, as well as in library screening. Return to Assignment
What is a probe in molecular biology? -a DNA or an RNA molecule used in hybridization reactions -an instrument used to manipulate cells in culture -a type of vector system -Probes are not used in molecular biology.
Evolutionary events leading to the emergence of new species and other taxonomic groups Genetic changes within members of a population can give rise to reproductive isolation resulting in the appearance of new species
What is macroevolution? -The evolution of macroorganisms -The evolution of major structural elements in the body plan of multicellular organisms -Evolutionary events leading to the emergence of new species and other taxonomic groups -Evolutionary changes that occur over long periods of time.
The sum of relevant individual alleles in a population is equal to 100% of those alleles.
What is meant by the equation p + q = 1.0? -The sum of male and female zygotes in a population is equal to 100% of the generation. -The sum of male and female traits in a population is equal to 100% of the heritable strains. -The sum of relevant individual alleles in a population is equal to 100% of those alleles. -The sum of male and female individuals with all genotypes is equal to 100% of the reproductive success.
an identical copy of a DNA molecule, a cell, or an organism
What is the definition of a clone? -an identical copy of a DNA molecule, a cell, or an organism -a circular DNA molecule that is able to replicate by itself -a non-identical DNA molecule produced by recombinant DNA technology -a new combination of DNA molecules that is not found naturally
selection
What is the differential reproduction of genotypes, resulting from their variable fitness? discrimination genetic drift evolution selection
They provide a defense mechanism against infection by viruses.
What is the function of restriction endonucleases in bacteria? -They serve no function. -They provide a defense mechanism against infection by viruses. -They allow bacteria to engineer new DNA fragments. -They allow bacteria to genetically recombine with other bacteria.
Gene Therapy adds in a gene at a random place. Editing allows target changes.
What is the fundamental leap between gene therapy and gene editing? -Gene therapy uses a virus vector and gene editing does not. -Gene Therapy adds in a gene at a random place. Editing allows target changes. -Gene therapy has achieved success in medicine but unfortunately not gene editing.
AUG; methionine
What is the initiator triplet in both bacteria and eukaryotes? What amino acid is recruited by this triplet? AUG; arginine UAA, UGA, or UAG; methionine UAA, UGA, or UAG; no amino acid called in UAA, UGA, or UAG; arginine AUG; methionine
hybridizes to a target sequence
What is the main purpose of a DNA probe? hybridizes to a target sequence binds to proteins extend the growing polynucleotide cuts DNA targets
The sequence of the gene must be known in order to design probes to locate the gene in the library.
What is the most serious drawback to using library screening to study genetics? -The product of the gene must be known in order to design enzyme probes to locate the gene in the library. -The promoter of the gene must be known in order to design primers to amplify the gene in the library. -The sequence of the gene must be known in order to design probes to locate the gene in the library. -The sequence of adjacent genes must be known in order to identify all the copies of the gene in the library.
codon
What is the name given to the three bases in a messenger RNA that bind to the anticodon of tRNA to specify an amino acid placement in a protein? codon rho protein anti-anticodon cistron
chaperone
What is the name of the protein that helps fold other proteins into their final and functional form? proteasomes ubiquitin flippase collagen chaperone
denaturation, annealing primers, elongation
What is the order of the three main steps in a PCR? -denaturation, elongation, annealing primers -denaturation, annealing primers, elongation -annealing primers, denaturation, elongation -elongation, annealing primers, denaturation
To separate the double‑stranded DNA
What is the purpose of raising the temperature to 90-95°C at the beginning of each cycle of PCR? To renature two single DNA strands To attach the primer To separate the double‑stranded DNA To extend the primer
e.Both a and b Rationale Because they lack the 3¢ oxygen required to form a phosphodiester bond with another nucleotide, dideoxynucleotides will cause chain termination whenever inserted at their base. The d d N T P is labeled with a fluorescent tag so that it can be identified by laser scanning and detection.
What is the purpose of the dideoxynucleotides in computer-automated D N A sequencing? a.To cause defined chain termination b.To label the synthesized D N A c.To help transfer the D N A to the membrane d.To aid in electrophoresis e.Both a and b
G T Fs bind to the core promoter and allow transcriptional initiation Rationale In eukaryotes, the R N A polymerase needs the G T Fs to recruit it to the promoter, and allow it to begin transcription. Without G T Fs, there will no transcription.
What is the role of general transcription factors (G T Fs)? -G T Fs bind to enhancers or silencers and regulate transcription -G T Fs bind to the core promoter and allow transcriptional initiation -G T Fs are cis-acting regulatory sequences -G T Fs regulate the length of the m R N A -G T Fs are part of the R N A polymerase II holoenzyme, and control transcription initiation
population
What is the term given to a group of individuals belonging to the same species that live in a defined geographic area that actually or potentially interbreed? cytogenetics population genetics hybrid vigor consanguinity
immunity to malaria
What is the unique health benefit of carriers of the sickle cell mutation? -immunity to malaria -higher adaptability to a lower oxygen environment -increased muscle tone
RF1 and RF2
What signals termination of translation in bacteria? -RF1 and RF2 -ribozymes -a tRNA specific to the stop codon enters the ribosome's A site -EF-Tu and EF-G -the stop amino acid is attached to the growing peptide chain
reproductive isolation
What single event is probably common to all occurrences of speciation? founder effect genetic drift genetic bottleneck reproductive isolation
IVF
What type of reproductive technology is required for germline gene editing under current conditions? Gestational Surrogacy Traditional Surrogacy IVF
3
When a 5-kb circular plasmid is digested with a restriction enzyme that has three recognition sites on the plasmid, how many bands can be visualized on an agarose gel? 1 2 3 4
either RF1 or RF2 release factors
When a codon in an mRNAmRNA with the sequence 5′-UAA-3′5′-UAA-3′ enters the A site of a ribosome, it is not recognized by a tRNAtRNA with a complementary anticodon. What recognizes it instead? -5S rRNA molecule -either RF1 or RF2 elongation factors -RF4 elongation factor -RF4 release factor -either RF1 or RF2 release factors -ATP molecule
-5′-UAA-3′ is one of the three stop codons. -There is no amynoacyl tRNA that corresponds to 5′-UAA-3′.
When a codon in an mRNAmRNA with the sequence 5′-UAA-3′5′-UAA-3′ enters the A site of a ribosome, it is not recognized by a tRNAtRNA with a complementary anticodon. Why not? Choose all that apply. -5′-UAA-3′ is one of the three stop codons. -There is no amynoacyl tRNA that corresponds to 5′-UAA-3′. -5′-UAA-3′ is recognized in the P site of a ribosome. -5′-UAA-3′ is the start codon.
is attached to the tRNA occupying the A site
When a peptide bond is formed between two amino acids, one is attached to the tRNA occupying the P site and the other _______. -is free in the cytoplasm -is attached through hydrogen bonds to the mRNA -is attached to the tRNA occupying the E site -is attached to the tRNA occupying the A site
The sticky ends have hydrogen bonds that help re-anneal the cut DNA.
When choosing a restriction enzyme for use in recombinant DNA technologies, it is often preferred that the enzyme generate cohesive, or "sticky," ends. Why is this preferred? -The sticky ends prevent the DNA from re-annealing to any DNA. -The sticky ends stick to the purification medium making the fragments easier to purify. -The sticky ends do not have hydrogen bonds to help in re-annealing the cut DNA. -The sticky ends make the DNA bind tighter to any cut DNA. -The sticky ends have hydrogen bonds that help re-anneal the cut DNA.
TATA
When considering the initiation of transcription, one often finds consensus sequences located in the region of the DNA where RNA polymerase(s) binds. Which of the following is a common consensus sequence? TTTTAAAA any trinucleotide repeat GGTTC satellite DNAs TATA
e)all four ddNTPs must be present
When performing a sequencing reaction using Sanger sequencing, which ddNTPs must be included in the reaction? a)ddATP b)ddCTP c)ddTTP d)ddGTP e)all four ddNTPs must be present
the code is triplet
When scientists were attempting to determine the structure of the genetic code, Crick and coworkers found that when three base additions or three base deletions occurred in a single gene, the wild-type phenotype was sometimes restored. These data supported the hypothesis that ________. -AUG is the initiating triplet -there are three amino acids per base -the code contains internal punctuation -the code is triplet -the code is overlapping
internal processing alteration of 5′ end alteration of 3′ end
Where do various forms of posttranscriptional processing in eukaryotes take place on the mRNA? Select all that apply. internal processing alteration of 5′ end addition of amino acid sequences alteration of 3′ end
no migration, mutation or, genetic drift
Which assumption pertains to a population in a Hardy-Weinberg equilibrium? -a selectively mating population -a small population -a selective advantage of one genotype -no migration, mutation or, genetic drift
enzymes
Which class of protein functions primarily by lowering the energy of activation during a reaction? chaperones enzymes prions heat-shock proteins
Homogentisic acid
Which compound accumulates in the metabolic disorder alkaptonuria? Phenylalanine hydroxylase Tyrosine Phenylalanine Homogentisic acid
competition for survival
Which factor contributes to the phenomenon of natural selection? genetic homogeneity in a population lack of competition in mating underpopulation competition for survival
c.In their linear form, YACs contain telomeres at each end for stability, an origin of replication, and they can be used to clone up to 2-Mb pairs of DNA. A YAC also contains a yeast centromere along with selectable markers and a number of restriction sites. This allows for the insertion of up to 2-Mb pairs of DNA.
Which features make yeast artificial chromosomes (YACs) an excellent cloning tool? a.YACs are large but low copy number plasmids that can accept DNA inserts in the 100- to 300-kb range. ● b.The YAC allows for the expression of bacterial genes. ● c.In their linear form, YACs contain telomeres at each end for stability, an origin of replication, and they can be used to clone up to 2-Mb pairs of DNA. A YAC also contains a yeast centromere along with selectable markers and a number of restriction sites. This allows for the insertion of up to 2-Mb pairs of DNA. ● d.Eukaryotic genes are relatively small. Cloning into a YAC allows for the function and the structure of these genes to be studied.
reproductive isolating mechanisms
Which general term is used to group various biological and behavioral properties of organisms that act to prevent or reduce interbreeding? inbreeding genetic divergence phyletic evolution allopatric speciation reproductive isolating mechanisms
a.The ability to carry D N A fragments of up to 200 kilobit Rationale Although this feature may be necessary for some applications, it is not necessary for most. Prokaryotic genes are much smaller than 200 k b, as are c D N A copies of eukaryotic genes.
Which is the following is not a necessary feature of a good cloning vector? a.The ability to carry D N A fragments of up to 200 k b b.The ability to be replicated c.Restriction site(s) for the insertion of a foreign D N A fragment d.A selectable marker gene e.The ability to be isolated from the host cell
secondary The alpha helix and the beta-pleated sheet are examples of secondary structures that are formed as a result of the polypeptide chain folding back on itself, generated by interactions of H-bonds between nearby amino acids.
Which level of protein structure do beta-pleated sheets and alpha helices represent? Tertiary Secondary Primary Quaternary
electrophoresis
Which method is often used to analyze proteins and nucleic acids by physical separation when estimating genetic variation in populations? in situ hybridization fluorometry absorption spectrophotometry electrophoresis centrifugation
σ (sigma)
Which of the following bacterial RNA polymerase subunits is found in the holoenzyme, but not the core enzyme? β (beta) β (beta prime) α (alpha) ω (omega) σ (sigma)
a. It provides a site for ribosome binding in the cytoplasm. b. To protect the transcript from degradation
Which of the following best describe(s) the function of the 5' mRNA cap? Check all that apply. a. It provides a site for ribosome binding in the cytoplasm. b. To protect the transcript from degradation c. To provide a binding site for poly(A) polymerase d. Termination of transcription
A DNA molecule that accepts DNA fragments and replicates the fragment in a host.
Which of the following best describes a cloning vector? -A DNA molecule that accepts DNA fragments and replicates the fragment in a host. -The fragment of DNA encoding a gene of interest. -The direction in which DNA is cloned. -A DNA molecule that accepts DNA fragments and degrades them in a host.
The small ribosomal subunit binds to an mRNA sequence near the 5' end of the transcript
Which of the following best describes the first step in the formation of the translation initiation complex? -The large ribosomal subunit binds to the small ribosomal subunit. -The small ribosomal subunit binds to an mRNA sequence near the 5' end of the transcript -The small ribosomal subunit binds to an mRNA sequence near the 3' end of the transcript. -The large ribosomal subunit binds to an mRNA sequence near the 5' end of the transcript
An organism that is negative for alleles coding a gene of interest.
Which of the following describes a "knock-out" organism? -An organism that is positive for alleles coding a gene of interest. -An organism that loses consciousness randomly. -An organism that is negative for alleles coding a gene of interest. -An organism that is capable of out-competing another organism.
Lambda arms
Which of the following elements is not found in a plasmid? lacZ gene Polylinker Lambda arms Antibiotic resistance
Spliceosomal introns are removed using large protein-based enzyme complexes.
Which of the following intron groups is matched appropriately with a true statement? -Spliceosomal introns are removed using the catalytic ability of the intron itself. -Group I introns are removed from rRNAs using large protein-based enzyme complexes. -Group I introns are removed from rRNAs that are found in mitochondria and chloroplasts. -Group II introns are removed from mRNA in mammals. -Spliceosomal introns are removed using large protein-based enzyme complexes.
subject to mutation
Which of the following is NOT characteristic of the ideal population on which the Hardy-Weinberg law is based? subject to mutation random mating no selection infinitely large population
Exon splicing catalyzed by the spliceosome
Which of the following is characteristic of transcription in eukaryotes but not in prokaryotes? -A 3' untranslated trailer sequence -Exon splicing catalyzed by the spliceosome -A 5' untranslated leader sequence -A single transcript may be transcribed and translated simultaneously.
The genetic code is degenerate.
Which of the following is true regarding the genetic code? -The genetic code is overlapping. -The genetic code has three start codons and one stop codon. -The genetic code is degenerate. -The genetic code is ambiguous. -The genetic code is considered to not be universal.
A tRNA molecule that has an amino acid attached to it is called a charged tRNA.
Which of the following is true regarding the tRNA structure? -A tRNA molecule that has an amino acid attached to it is called a charged tRNA. -The nucleotides found in a tRNA molecule can only be adenine, uracil, guanine, and cytosine. -The tRNA binds to an mRNA's codon at the variable loop. -The anticodon is found at the 3 end of the tRNA molecule. -An amino acid binds to the 5 end of the tRNA molecule.
Transcription, 5' cap addition, addition of poly-A tail, exon splicing, passage through nuclear membrane
Which of the following lists steps of mRNA production in eukaryotes in the correct order? -Transcription, addition of poly-A tail, 5' cap addition, exon splicing, passage through nuclear membrane -Transcription, 5' cap addition, addition of poly-A tail, passage through nuclear membrane, exon splicing -Transcription, 5' cap addition, addition of poly-A tail, exon splicing, passage through nuclear membrane -5' cap addition, addition of poly-A tail, exon splicing, passage through nuclear membrane, transcription
Ligase
Which of the following molecules is not required for a PCR reaction? DNA Ligase DNTPs Primer
The cells can grow on minimal medium + valine. The cells can grow if the nutrient it cannot produce itself (i.e., valine) is supplied in the medium.
Which of the following statements about a Neurospora valine auxotroph is true? The cells can grow on minimal medium + histidine. The cells can grow on minimal medium + valine. The cells cannot grow on complete medium. The cells can grow on minimal medium.
A domain consists of a single type of secondary structure.
Which of the following statements about a protein domain is FALSE? -Each protein contains at least one domain but may contain several domains. -Domains may have resulted from exons of different genes, which were reshuffled during evolution. -Within a single protein, different domains may serve different functions, such as ligand-binding or catalysis. -A domain consists of a single type of secondary structure.
It attaches a specific amino acid to a tRNA molecule.
Which of the following statements best describes the function of aminoacyl tRNA synthetase? -It provides the energy required to attach a specific amino acid to a tRNA molecule. -It helps tRNA synthesize proteins. -It synthesizes tRNA molecules. -It attaches a specific amino acid to a tRNA molecule.
c.5¢-A T G C A T-3¢ Rationale A palindromic D N A sequence is identical on both strands when read in the 5¢ to 3¢ direction.
Which of these D N A sequences is palindromic when double-stranded? a.5¢-A T G G T A-3¢ b.5¢-A T G A T G-3¢ c.5¢-A T G C A T-3¢ d.5¢-T A T C G C-3¢ e.5¢-C C C C C C-3¢
Prezygotic mechanisms are most efficient because they occur before resources are expended in the processes of mating.
Which of these is regarded as more efficient? -Prezygotic mechanisms are most efficient because of hybrid nonviability. -Postzygotic mechanisms are most efficient because of seasonal differences when the populations are sexually mature. -Prezygotic mechanisms are most efficient because they occur before resources are expended in the processes of mating. -Postzygotic mechanisms are most efficient because of hybrid nonviability.
enzymes
Which protein class directly controls many of the metabolic reactions within a cell? hydrophilic proteins repressor proteins structural proteins enzymes operator proteins
3' end
Which region of a tRNA molecule binds to amino acids? Variable loop 3′ end Anticodon loop Codon loop
a-c
Which statements are true? a. Eukaryotic RNA polymerase II requires general transcription factors for initiation of transcription. b. Three different RNA polymerases in eukaryotes transcribe different classes of genes. c. Since prokaryotes lack a nucleus, translation can begin before the transcript is fully transcribed. d. Intrinsic termination in prokaryotes occurs when the rho termination factor interacts with the growing RNA transcript.
fitness
Which term is given to the measure of the proportion of offspring that a particular phenotype will contribute to the next generation? fitness selection genetic variability mutation
a.Denaturation, annealing, and extension
Which three steps constitute a PCR cycle? a.Denaturation, annealing, and extension b.Inactivation, activation, and transfer c.Naturation, annealing, and photolysing d.Transfection, transformation, and transduction
cDNA libraries represent expressed genes from specific cell types under specific conditions. Noncoding sequences are not included
Which type of DNA library represents the genes expressed by a given cell at a certain time? protein RNA cDNA genomic
Frameshift Insertions or deletions of one or two nucleotides resulted in frameshift mutations. Insertion or deletion of three nucleotides resulted in insertion or deletion of a single amino acid and did not shift the reading frame.
Which type of mutation helped lead to the understanding that the genetic code is based on triplets? -Nonsense -Missense mutation within the promoter -Base substitution (substitution of one base for another) -Frameshift
c.reverse transcriptase P C R (R T-P C R) Rationale Southern blots examine D N A, and Western blots examine protein expression. Using transgenic animals would not allow you to measure your gene of interest; next-generation sequencing has awesome power, but is too much technology for this small a question! R T-P C R will quantitate R N A and is an excellent method to quickly and sensitively measure R N A levels.
You are interested in knowing whether the addition of estrogen to your cell culture induces expression of m R N A from your gene of interest. Of the following choices, a good way to determine that is using __________. a.Southern blot b.Western blot c.reverse transcriptase P C R (R T-P C R) d.transgenic female animals e.next-generation sequencing
Disruptive selection
You collect samples of a population of bacteria which exists near hydrothermal vents on the ocean floor. Temperatures near the vents average 80°C, while a few meters away the temperature is only a few degrees above freezing. You find that the majority of bacteria in your samples require temperatures near either of those extremes to grow. Which of the following types of selection appear to be acting on this population? Dispersive selection Disruptive selection Directional selection Stabilizing selection
b. auxotrophic for purines
You irradiate spores of Neurospora to induce mutations. While normal spores can grow on minimal medium, you isolate one that cannot. When you inoculate supplemented medium with spores from this mutant, you observe the following results. From this, you can conclude your mutant is *table of "+++" growth seen on rich medium and minimal medium + purines* a. auxotrophic for amino acids b. auxotrophic for purines c. auxotrophic for pyrimidines d. auxotrophic for adenine e. auxotrophic for pyrimidines, amino acids, and adenine
a)ACCTT
ddATP, ddTTP, ddCTP, and ddGTP are labeled with red, green, yellow, and blue fluorescent dyes, respectively. A five-base read from a sequencing reaction produced the following color sequence, read by the computer: red, yellow, yellow, green, green. What is the sequence of the template DNA? a)ACCTT b)AAGGT c)TGGAA d)TTCCA
have double-stranded regions
t R N A s _____. -have double-stranded regions -contain unusual nucleotides, encoded by genes with nonstandard bases -can be recognized by several aminoacyl-t R N A synthetases -can carry more than one type of amino acid per molecule -consist of two subunits