Deck 7: The Blueprint of Life, from DNA to Protein

Question 1

Which is False about the RNA transcript?

A) It is formed using the DNA minus strand as a template.
B) It has the same 5'-3' orientation as the DNA positive strand.
C) It is made in short fragments that are then stitched together.
D) The template starts at the promoter region.
E) All the answers are False.

Answer 1

C

Question 2

The lagging strand

A) is another name for any single-stranded DNA found in slowly dividing cells.
B) is formed during RNA replication because of the nature of the enzymes involved in it.
C) is formed during DNA replication because of the antiparallel nature of DNA.
D) is always the bottom strand of DNA or RNA during the replication process.
E) is always the upper strand of DNA or RNA during the replication process.

Answer 2

C

Question 3

DNA replication is

A) conservative.
B) interspersive.
C) semiconservative.
D) redundant.
E) configurative.

Answer 3

C

Question 4

Which is True about DNA replication?

A) It is semiconservative.
B) It starts at an origin of replication.
C) It is bidirectional.
D) It requires RNA primers.
E) All of the choices are correct.

Question 5

Which may be or is an RNA molecule?

A) AGCCTAC and GGGCCCA
B) GGGCCCA and AAATTTA
C) GGGCCCA and GCCCUUA
D) GCCCUUA and AAATTTA
E) AGCCTAC and GGUCCCU

Question 6

Which is True about prokaryotic (bacterial) RNA polymerase?

A) It is used during transcription.
B) It requires a primer.
C) It has a detachable subunit, alpha factor, which recognizes the promoter.
D) It reads the template in the 5'-3' direction.
E) All of the choices are True.

Question 7

The specific sequence of nucleotides in the DNA to which the RNA polymerase binds is the

A) regulatory region.
B) promoter region.
C) sigma region.
D) core region.
E) starter region.

Question 8

The term antiparallel

A) refers to the structure of single-stranded RNA.
B) is synonymous with semiconservative.
C) refers to the opposite orientation of the two strands in DNA.
D) refers to a type of prokaryotic replication.
E) refers to the sequence of nucleotides in DNA.

Question 9

DNA is characterized by which of the following feature(s)?

A) Ribose AND single-stranded
B) Single-stranded AND uracil
C) Deoxyribose AND single-stranded
D) Deoxyribose AND thymine
E) Thymine AND uracil

Question 10

Which of the following is/are True of DNA replication?

A) It starts at the origin of duplication.
B) Nucleotides are added to the 3' end.
C) It requires a DNA primer to get started.
D) It is carried out by transcriptases.
E) All of the choices are True.

Question 11

Which pairing is incorrect?

A) A:T
B) G:C
C) A:U
D) A:G
E) C:G

Question 12

The 3' end of DNA

A) has a hydroxyl group attached to the number 3 carbon of deoxyribose.
B) attaches to the 3' phosphate group of the incoming nucleotide.
C) always has thymine and uracil attached to it.
D) usually has guanine and guanine attached to it.
E) has a hydroxyl group attached to the number 3 carbon of ribose.

Question 13

RNA is characterized by which one of the following features?

A) Deoxyribose
B) Thymine
C) Ribose
D) Double-stranded
E) All of the answer choices are correct.

Question 14

Which is NOT True of RNA?

A) It is usually single-stranded.
B) It contains both uracil and thymine.
C) It functions in the cytoplasm.
D) It contains ribose.
E) It is a component of ribosomes.

Question 15

The transcription terminator

A) results in a hairpin loop structure in RNA, AND stops DNA polymerase.
B) results in a hairpin loop structure in RNA, AND results in the polymerase falling off the DNA template.
C) stops DNA polymerase, AND results in the polymerase falling off the DNA template.
D) stops DNA polymerase, AND adds a terminator nucleotide to the RNA.
E) adds a terminator nucleotide to the RNA, AND results in a hairpin loop structure in RNA.

Question 16

The two strands of DNA are bonded to one another by

A) covalent bonds.
B) oxygen bonds.
C) hydrogen bonds.
D) carbon bonds.
E) disulfide bridges.

Question 17

The report that genes direct the synthesis of proteins was first made by

A) Lederberg.
B) Watson and Crick.
C) Beadle and Tatum.
D) Mendel.
E) Curie.

Question 18

GCCCAAAG is a molecule of

A) RNA.
B) DNA.
C) protein.
D) DNA OR lipid
E) Cannot tell as written.

Question 19

Without changing the sequence or the orientation of the sequence(s), which is/are complementary to the sequence 5' AGGCUAAC 3'?

A) 5' TCCGATTG 3'
B) 3' TCCGATTG 5'
C) 5' CTTAGCCT 3'
D) 3' TAAGCTTA 5'
E) 3' TCCGATTC 5' AND 5' CTTAGCCT 3'

Question 20

What structure is indicated by: 10A, 15T, 3G, 7C?

A) Double-stranded DNA
B) Double-stranded RNA
C) Single-stranded DNA
D) Single-stranded RNA
E) A DNA virus

Question 21

Post-translational modification may include

A) formation of exons and introns.
B) folding of the protein, often with the aid of chaperones.
C) removal of the signal sequence.
D) addition of glycine tags.
E) folding of the protein, often with the aid of chaperones, AND removal of the signal sequence.

Question 22

Ribozymes

A) are complexes of ribosomes and RNA.
B) are self-catalytic RNA.
C) suggest that nucleic acids evolved before proteins.
D) are enzymes that degrade RNA and therefore have potential for clinical applications.
E) are self-catalytic RNA AND suggest that nucleic acids evolved before proteins.

Question 23

The placement of the amino acid during translation is determined by the

A) DNase, which transcribes both molecules.
B) complementarity of the codon-anticodon.
C) sequence of nucleotides at the 5' end of the tRNA.
D) secondary structure of the newly forming protein.
E) antiparallel nature of mRNA.

Question 24

A stop codon

A) codes for the stop amino acid s-methyl-methionine.
B) forms a hairpin loop forcing the ribosome to fall off.
C) codes for no amino acid.
D) enhances the binding of the e-polymerase.
E) codes for the stop amino acid AUG.

Question 25

Quorum sensing

A) is used by bacteria to sense the density of cells within their population AND is used by eukaryotes to sense the presence of bacteria in their environment.
B) involves the production and monitoring of signaling molecules AND is used by eukaryotes to sense the presence of bacteria within their population.
C) is used by bacteria to limit the density of cells in a population AND is used by eukaryotes to sense the presence of bacteria within their environment.
D) involves the production and monitoring of signaling molecules AND is used by bacteria to sense the density of cells within their population.
E) is used by bacteria to limit the density of cells in a population AND is used by eukaryotes to sense the presence of pathogens within their cells.

Question 26

The scientists responsible for the idea that RNA can act as a catalyst were

A) Watson and Crick.
B) Beadle and Tatum.
C) Altman and Cech.
D) Lederberg and Stanley.
E) Curie and Curie.

Question 27

The P-site

A) is found on the polymerase enzyme.
B) is an allosteric site on an enzyme.
C) is a promoter site on the ribosome.
D) is the peptidyl site on the ribosome.
E) is an allosteric site AND is a promoter site.

Question 28

The amino acid that is placed first during translation in bacteria, mitochondria, and chloroplasts is

A) methionine.
B) N-formyl-methionine.
C) glycine.
D) N-formyl-glycine.
E) the promoter.

Question 29

Some segments of the precursor mRNA in eukaryotes are non-coding and are called

A) exons.
B) introns.
C) integrans.
D) uselessans.
E) genes.

Question 30

The ribosomes

A) move along the tRNA in a 3'-5' direction AND provide a platform that brings the amino acids into a favorable position for joining.
B) move along the mRNA in a 3'-5' direction AND provide a platform that brings the amino acids into a favorable position for joining.
C) move along the mRNA in a 5'-3' direction AND provide a platform that brings the amino acids into a favorable position for joining.
D) move along the DNA in a 5'-3' direction AND provide a platform that brings the amino acids into a favorable position for joining.
E) move along the DNA in a 3'-5' direction AND provide a platform that brings the amino acids into a favorable position for joining.

Question 31

Signal transduction

A) is the relay of information about conditions outside a cell to inside the cell.
B) often relies on a four component system.
C) never involves phosphorylation of various molecules.
D) is used by certain pathogens to sense high magnesium conditions.
E) All of the answer choices are correct.

Question 32

How many nucleotides are in a codon?

A) 1
B) 2
C) 3
D) 4
E) 5

Question 33

The genetic code has more than one codon for some amino acids. This is an example of

A) evolution.
B) stringency.
C) redundancy.
D) translation.
E) replication.

Question 34

AUG

A) is only used as the start codon.
B) codes for methionine.
C) determines the reading frame.
D) is one of the stop codons.
E) codes for methionine AND determines the reading frame.

Question 35

What is the number of tRNA molecules that may be associated with translation?

A) 20
B) Fewer than 20
C) 64
D) Fewer than 64
E) 2

Question 36

There are ________ codons to code for the 20 possible amino acids.

A) 20
B) 30
C) 61
D) 64
E) 3

Question 37

The E-site

A) is found on the RNA polymerase enzyme.
B) is responsible for the release of the tRNA.
C) is found on the 35S polysome.
D) is the aminoacyl site on the ribosome.
E) is another name for anticodon.

Question 38

Bacteria use ________ attached to the polymerase to direct RNA polymerase to promoters; eukaryotic cells use ________ that attach directly to the DNA first instead.

A) sigma factors; transcription factors
B) transcription factors; sigma factors
C) ribosomes; sigma factors
D) tRNA; rRNA
E) sigma factors; tRNA

Question 39

Which molecule carries an anticodon?

A) DNA
B) mRNA
C) rRNA
D) tRNA
E) ribosome

Question 40

All of the following are True about DNA sequence analysis EXCEPT

A) the (−) strand of DNA is used.
B) the start codon is ATG.
C) ORFs are searched for.
D) codon usage is a helpful indicator for protein coding areas.
E) All of the answer choices are correct.

Question 41

The lac operon

A) is an example of positive control.
B) produces lactose.
C) is an example of a regulon.
D) is an example of negative control.
E) is an example of constitutive control.

Question 42

The DNA site to which the repressor protein binds is the

A) operon.
B) regulon.
C) operator.
D) repressor.
E) starter.

Question 43

The genetic code is nearly universal.

Question 44

The set of genes in bacteria that are linked together and transcribed as a single unit is referred to as a(n)

A) operon.
B) regulon.
C) operator.
D) repressor.
E) promoter.

Question 45

DNA replication is usually unidirectional.

Question 46

Antisense RNA is the complement of the plus strand and may be useful in inhibiting translation.

Question 47

CAP

A) is involved in positive control AND stands for cyclic amp protein.
B) is involved in positive control AND works in conjunction with cAMP.
C) stands for cyclic amp protein AND is a regulon.
D) stands for cyclic amp protein AND works in conjunction with cAMP.
E) is involved in negative control AND works in conjunction with cAMP.

Question 48

Glucose

A) is preferentially used over lactose in E. coli as a result of catabolite repression AND levels are correlated with cAMP levels.
B) is preferentially used over sucrose in E. coli as a result of catabolite repression AND levels are directly sensed via catabolite repression.
C) is preferentially used over lactose in E. coli as a result of catabolite repression AND glucose levels are the inverse of cAMP levels.
D) is preferentially used over lactose in E. coli as a result of catabolite repression AND levels directly affect the production of lactose dehydrogenase.
E) is preferentially used over sucrose in E. coli as a result of catabolite repression AND levels are correlated with cAMP levels.

Question 49

Gene regulation may entail

A) turning on genes only when needed.
B) turning off genes when not needed.
C) turning on or off entire groups of genes.
D) All of the answer choices are correct.
E) None of the answer choices is correct.

Question 50

The regulatory protein

A) binds to the promoter region of DNA.
B) may inhibit or enhance transcription.
C) may control translation of the operon.
D) affects the activity of the DNA polymerase.
E) binds to the operator region of RNA.

Question 51

The minus strand of DNA serves as the template for RNA production.

Question 52

One end of a strand of DNA is different from the other end.

Question 53

RNAi

A) is the form of mRNA that initiates translation in most pathogenic bacteria.
B) uses short pieces of double-stranded RNA to direct the degradation of specific RNA transcripts.
C) is a mechanism of genetic regulation found in all prokaryotes.
D) is any chemical that inhibits transcription.
E) uses short pieces of single-stranded RNA to direct the degradation of specific RNA transcripts 

Question 54

Activators

A) are involved in negative control AND bind to the terminator.
B) are involved in positive control AND bind to the terminator.
C) are allosteric proteins AND are involved in positive control .
D) are allosteric proteins AND are involved in negative control.
E) are involved in negative control AND bind to the start codon.

Question 55

Adenine binds to thymine via three hydrogen bonds.

Question 56

The molecules that bind to a repressor and cause it to no longer bind to the operator are called

A) activators.
B) repressors.
C) introns.
D) inducers.
E) stimulons.

Question 57

Negative control means a regulator molecule is

A) bound, and transcription starts.
B) removed, and transcription is inhibited.
C) bound, and transcription is inhibited.
D) removed, and transcription starts.
E) bound, and transcription is inhibited OR removed, and transcription starts.

Question 58

A codon consists of two nucleotides.

Question 59

Repressors

A) bind or do not bind to the operator depending on their shape (conformation) AND are involved in positive control.
B) bind or do not bind to the operator depending on their shape (conformation) AND are involved in negative control.
C) always bind to the promoter AND are involved in positive control.
D) always bind to the promoter AND are involved in negative control.
E) always bind to the ribosome AND are involved in negative control.

Question 60

Operon(s) in bacteria

A) refers to a group of genes that are controlled in a coordinated manner AND involve monocistronic mRNA.
B) refers to a group of genes that are controlled in a coordinated manner AND involve both monocistronic and polycistronic DNA.
C) refers to a group of genes that are controlled in a coordinated manner AND involve monocistronic DNA.
D) refers to a group of genes that are controlled in a coordinated manner AND involve polycistronic DNA.
E) refers to a group of genes that are controlled in a coordinated manner AND involve polycistronic mRNA.

Question 61

How can some bacteria sense the density of cells in an environment?

A) Detecting the concentration of a signaling molecule.
B) Quantifying the accumulation of waste products.
C) Measuring the depletion of oxygen in the environment.
D) Sensing the depletion of water in the environment.
E) Detecting the accumulation of endospores.

Question 62

Ribozymes are non-protein molecules with catalytic activity.

Question 63

Transcription begins at the ________ and ends at the ________, while translation begins at the ________ and ends at the ________.

A) start codon; stop codon; promoter; terminator
B) promoter; stop codon; terminator; stop codon
C) promoter; start codon; terminator; stop codon
D) promoter; terminator; start codon; stop codon
E) initiator; ender; starter; stopper

Question 64

Which pair is INCORRECT?

A) Okazaki fragments-generated on the lagging strand during DNA replication.
B) Splicing-removal of introns from prokaryote mRNA following transcription.
C) Signal transduction-transmission of information from outside a cell to inside the cell.
D) Constitutive enzymes-enzymes that are constantly produced by a cell.
E) Promoter-nucleotide sequence to which RNA polymerase binds to start transcription.

Question 65

Which of the following is an example of phase variation?

A) N. gonorrhoeae expressing different types of pilin protein.
B) Influenza virus expressing variations of glycoprotein HA and NA spikes.
C) S. pyogenes producing a capsule of hyaluronic acid, which is also a host component.
D) E. coli producing pili for attachment to epithelial cells.
E) These are all examples of phase variation.

Question 66

Which of the following is INCORRECT?

A) Transcription is the conversion of DNA into RNA.
B) Replication is the process of duplicating a DNA molecule.
C) Binary fission is the process of bacterial cell division.
D) Transcription is the process of copying mRNA from DNA.
E) Translation is the process of synthesizing protein using information in mRNA.

Question 67

Why is it a good idea for a bacterial cell to be able to use glucose FIRST as an energy source (until it is depleted), THEN switch to lactose?

A) Lactose can only be used by a small number of bacteria as an energy source AND for conservation of energy: why use the energy to make the enzymes for breaking down lactose when glucose doesn't need any extra enzymes for breakdown?
B) For conservation of energy: why use the energy to make the enzymes for breaking down lactose when glucose doesn't need any extra enzymes for breakdown AND because breakdown of lactose produces inhibitory compounds.
C) Glucose is an easier compound to break down and obtain energy from than lactose AND for conservation of energy: why use the energy to make the enzymes for breaking down lactose when glucose doesn't need any extra enzymes for breakdown?
D) Glucose provides 10x as much energy when broken down as lactose AND for conservation of energy: why use the energy to make the enzymes for breaking down lactose when glucose doesn't need any extra enzymes for breakdown?
E) For conservation of energy: why use the energy to make the enzymes for breaking down lactose when glucose doesn't need any extra enzymes for breakdown AND because lactose always triggers endospore formation, which may be unnecessary.

Question 68

A graduate student is trying to isolate bacterial mRNA for an enzyme that will degrade trinitrotoluene (TNT). She's frustrated to find that the enzyme isn't produced when the bacterium in question is grown on nutrient agar. What might she do to solve the problem and obtain the mRNA?

A) Add nitrogen and toluene to the agar which will drive up synthesis of TNT, leading to production of the mRNA the student is looking for.
B) Add TNT to the agar-this will drive synthesis of the enzyme to degrade it, leading to production of the mRNA the student is looking for.
C) Remove glucose from the agar-this will cause the bacteria to shift to other compounds for their energy purposes.
D) Remove nitrogen and toluene from the agar which will lead to driving up synthesis of TNT, leading to production of the mRNA the student is looking for.
E) Remove TNT from the nutrient agar; it acts as an inhibitor of all microbial growth, and prevents the bacteria from synthesizing any enzymes at all.

Question 69

A regulatory protein binds to the operator in a strand of DNA, blocking transcription. The protein is

A) a repressor.
B) an inducer.
C) an operon.
D) a terminator.
E) an activator.

Question 70

For synthesis of an inducible enzyme to occur, 

A) a compound must bind to the repressor.
B) a compound must bind to the operator.
C) a product must bind to the terminator.
D) a corepressor must bind to the start codon.
E) lactose must be present without fructose.

Question 71

A drug that inhibits the activity of bacterial DNA gyrase ________ be a good antibiotic because ________.

A) would; it would inhibit all DNA synthesis
B) would NOT; it would inhibit all DNA synthesis, even our own cell's DNA synthesis
C) would; it would selectively inhibit bacterial DNA synthesis due to differences between bacterial/human gyrase
D) would NOT; the DNA replication machinery could still function, even with impaired DNA gyrase enzyme
E) would; it would selectively impair bacterial DNA structure thus killing the cells

Question 72

The anticodon determines which amino acid is linked to its tRNA.

Question 73

Cells are often ground up with abrasive to get to their internal enzymes/molecules, followed by removal of the abrasives. Here are two situations and two outcomes. What is the correct interpretation of the results?
In situation #1, radioactive amino acids are mixed with ground-up cell material. Radioactive proteins are produced.
In situation #2, radioactive amino acids AND the enzyme RNAse (an enzyme that degrades RNA) are mixed with ground-up cell material. No radioactive proteins are produced.

A) The mRNA from the cell can be used to make proteins with the radioactive amino acids in the first situation. In the second situation, the mRNA is destroyed by the RNAse before it can be translated into protein containing the radioactive amino acids.
B) The DNA from the cell can be translated into protein using the radioactive amino acids in the first situation. The RNAse in the second situation degrades the ribosomal RNA (rRNA), preventing ribosomes from forming and making proteins with the radioactive amino acids.
C) The radioactivity in the amino acids corrupts the tRNA molecules, leading to no protein production in the second scenario.
D) The radioactivity in the medium causes the DNA of the bacteria to mutate. This causes a malfunction of all the enzymes of that cell.
E) The results cannot be interpreted-there isn't enough information given in the question.

Question 74

DNA polymerases

A) add nucleotides to the 3' end of RNA during transcription.
B) generate short stretches of RNA called primers to initiate replication.
C) unwind the DNA template at the replication fork.
D) move in a 3' to 5' direction on the template DNA.
E) only add nucleotides to the leading strand during replication.

Question 75

The simultaneous regulation of many bacterial genes is

A) quorum sensing.
B) a regulon.
C) local control.
D) induction.
E) global control.

Question 76

If a DNA triplet is AGT, the mRNA codon would be ________ and the tRNA anticodon would be ________.

A) TCA; AGU
B) UCA; AGU
C) TGA; serine
D) UCA; stop
E) AGU; UGA

Question 77

When E. coli is grown in medium containing both glucose and lactose, 

A) the cells growth fastest after lactose is used up.
B) the cells use lactose first, then glucose.
C) the cells grow fastest initially when glucose is available.
D) the cells use the glucose and then stop growing.
E) the cells grow at the same rate until all sugars are depleted.

Question 78

Which tasks must a bacterial cell accomplish in order to multiply?

A) Replication, translation, protein synthesis
B) DNA duplication, RNA synthesis, protein synthesis
C) Protein synthesis, mitosis, capsule formation
D) Mitosis, gene expression, apoptosis
E) DNA replication, mitosis, cytokinesis

Question 79

Cells are often ground up with abrasive to get to their internal enzymes/molecules, followed by removal of the abrasives. Here are three situations and three outcomes. What is the correct interpretation of the results?
In situation #1, radioactive amino acids are added to cell material, and radioactive proteins are produced.
In situation #2, radioactive amino acids, cell material, and the enzyme DNAse (degrades DNA) are added together. Radioactive proteins are still produced.
In situation #3, the ground-up cell material is allowed to sit for 24 hours before radioactive amino acids and DNAse are added to it. No radioactive protein is produced. What is the most likely interpretation?

A) RNA polymerase has no activity after 24 hours, so no mRNA is transcribed and translated into radioactive proteins in the last scenario.
B) The radioactivity in the amino acids is altering/degrading the tRNA molecules, leading to no protein production in the last scenario.
C) Natural RNAses present in the ground-up material will degrade any existing mRNAs in that 24-hour interval. Added DNAses break down DNA so that new RNAs are not synthesized. This will lead to a loss of capability to translate protein in the last scenario.
D) The radioactivity in the amino acids completely disappears within 24 hours. Transcription and translation occur as usual, but there is no radioactivity left in the system, so proteins are untagged.
E) No conclusions can be made from the information given. More results are needed to interpret these experiments.

Question 80

Does the presence of introns/exons in eukaryotic cells provide more potential diversity in gene products (proteins) than is possible in prokaryotic cells?

A) It doesn't. There is the same potential for gene products (proteins) in a bacterium with 1,000 genes as there is in a eukaryotic cell with 1,000 genes.
B) It does. Each exon and each intron could be used individually and discretely to make a gene product (protein). Since bacteria lack these, they will have less ability to create different proteins.
C) It does. Exons/introns can be spliced together in different ways post-transcription to yield different mRNAs (and therefore, different proteins). Bacteria lack this system.
D) It does. Exons/introns can be spliced together in different ways at the DNA level to eventually yield different mRNAs (and therefore, different proteins). Bacteria lack this system.
E) It doesn't. Bacteria and eukaryotes have the same number of introns and exons, and can thus synthesize the same types and numbers of proteins.