BIOL 213 Quiz 5 & 6

Two individuals are represented in Figure 9-6; individual 1 is one of the parents of individual 2. The asterisk indicates the occurrence of a single mutation. What is the chance that individual 2 will inherit the mutation in individual 1? A) 100% B) 50% C) 1 in 100,000 D) none

B) 50%

Which of the following statements is FALSE? A) A mutation that arises in a mother's somatic cell often causes a disease in her daughter. B) All mutations in an asexually reproducing single-celled organism are passed on to the progeny. C) In an evolutionary sense, somatic cells exist only to help propagate germ-line cells. D) A mutation is passed on to offspring only if it is present in the germ line.

A) A mutation that arises in a mother's somatic cell often causes a disease in her daughter.

Which of the following statements about the Lac operon is FALSE? A) The Lac repressor binds when lactose is present in the cell. B) Even when the CAP activator is bound to DNA, if lactose is not present, the Lac operon will not be transcribed. C)The CAP activator can only bind DNA when it is bound to cAMP. D) The Lac operon only produces RNA when lactose is present and glucose is absent.

A) The Lac repressor binds when lactose is present in the cell.

Which of the following statements about transcriptional regulators is FALSE? A) Transcription regulators interact only with the sugar-phosphate backbone on the outside of the double helix to determine where to bind on the DNA helix. B) Transcription regulators will form hydrogen bonds, ionic bonds, and hydrophobic interactions with DNA. C) The DNA-binding motifs of transcription regulators usually bind in the major groove of the DNA helix. D) The binding of transcription regulators generally does not disrupt the hydrogen bonds that hold the double helix together.

A) Transcription regulators interact only with the sugar-phosphate backbone on the outside of the double helix to determine where to bind on the DNA helix.

You discover that the underlying cause of a disease is a protein that is now less stable than the non-disease-causing version of the protein. This change is most likely to be due to A) a mutation within a gene. B) a mutation within the regulatory DNA of a gene. C) gene duplication. D) horizontal gene transfer.

A) a mutation within a gene.

MicroRNAs A) are produced from a precursor miRNA transcript. B) are found only in humans. C) control gene expression by base-pairing with DNA sequences. D) can degrade RNAs by using their intrinsic catalytic activity.

A) are produced from a precursor miRNA transcript.

miRNAs, tRNAs, and rRNAs all A) do not code for proteins. B) act in the nucleus. C) are packaged with other proteins to form RISC. D) form base pairs with mRNA molecules.

A) do not code for proteins.

(Q012) You prepare bacterial cell extracts by lysing the cells and removing insoluble debris via centrifugation. These extracts provide the proteins required for DNA replication. Your DNA template is a small, double-stranded circular piece of DNA (a plasmid) with a single origin of replication and a single replication termination site. The termination site is on the opposite side of the plasmid from the origin.Figure 6-11 You decide to use different bacterial strains (each having one protein of the replication machinery mutated) in order to examine the role of individual proteins in the normal process of DNA replication. What part of the DNA replication process would be most directly affected if a strain of bacteria lacking primase were used to make the cell extracts? A) initiation of DNA synthesis B) Okazaki fragment synthesis C) leading-strand elongation D) lagging-strand completion

A) initiation of DNA synthesis

You prepare bacterial cell extracts by lysing the cells and removing insoluble debris via centrifugation. These extracts provide the proteins required for DNA replication. Your DNA template is a small, double-stranded circular piece of DNA (a plasmid) with a single origin of replication and a single replication termination site. The termination site is on the opposite side of the plasmid from the origin. Figure 6-11 What part of the DNA replication process would be most directly affected if a strain of bacteria lacking helicase were used to make the cell extracts? A) initiation of DNA synthesis B) Okazaki fragment synthesis C) leading-strand elongation D) lagging-strand completion

A) initiation of DNA synthesis

Which amino acid would you expect a tRNA with the anticodon 5´-CUU-3´ to carry? Table 7-29 A) lysine B) glutamic acid C) leucine D)phenylalanine

A) lysine

Specific regions of eukaryotic chromosomes contain sequence elements that are absolutely required for the proper transmission of genetic information from a mother cell to each daughter cell. Which of the following is NOT known to be one of these required elements in eukaryotes? A) protein-coding regions B) origins of replication C) telomeres D) centromeres

A) protein-coding regions

The DNA from two different species can often be distinguished by a difference in the A) ratio of A + T to G + C. B)ratio of A + G to C + T. C) ratio of sugar to phosphate. D) presence of bases other than A, G, C, and T.

A) ratio of A + T to G + C.

Imagine that an RNA polymerase is transcribing a segment of DNA that contains the following sequence: 5′-AGTCTAGGCACTGA-3′ 3′-TCAGATCCGTGACT-5′ If the polymerase is transcribing from this segment of DNA from left to right, which strand (top or bottom) is the template? A) the bottom strand B) the top strand

A) the bottom strand

Homologous recombination is an important mechanism in which organisms use a "backup" copy of the DNA as a template to fix double-strand breaks without loss of genetic information. Which of the following is NOT necessary for homologous recombination to occur? A) 3´ DNA strand overhangs B) 5´ DNA strand overhangs C) a long stretch of sequence similarity D) nucleases

B) 5´ DNA strand overhangs

You have a piece of DNA that includes the following sequence:5´-ATAGGCATTCGATCCGGATAGCAT-3´3´-TATCCGTAAGCTAGGCCTATCGTA-5´ Which of the following RNA molecules could be transcribed from this piece of DNA? A) -UAUCCGUAAGCUAGGCCUAUGCUA-3´ B) 5´-AUAGGCAUUCGAUCCGGAUAGCAU-3´ C) 5´-UACGAUAGGCCUAGCUUACGGAUA-3´ D) Not Selected none of these answers are correct.

B) 5´-AUAGGCAUUCGAUCCGGAUAGCAU-3´

You prepare bacterial cell extracts by lysing the cells and removing insoluble debris via centrifugation. These extracts provide the proteins required for DNA replication. Your DNA template is a small, double-stranded circular piece of DNA (a plasmid) with a single origin of replication and a single replication termination site. The termination site is on the opposite side of the plasmid from the origin. Figure 6-11 What part of the DNA replication process would be most directly affected if a strain of bacteria lacking single-strand binding protein were used to make the cell extracts? A) intiation of DNA synthesis B) Okazaki fragment synthesis C) leading-strand elongation D) lagging-strand completion

B) Okazaki fragment synthesis

Which of the following statements about sequence proofreading during DNA replication is FALSE? A) e exonuclease activity is in a different domain of the DNA polymerase. B) The exonuclease activity cleaves DNA in the 5´-to-3´ direction. C) The DNA proofreading activity occurs concomitantly with strand elongation. D) If an incorrect base is added, it is "unpaired" before removal.

B) The exonuclease activity cleaves DNA in the 5´-to-3´ direction.

Fred Griffith studied two strains of Streptococcus pneumonia, one that causes a lethal infection when injected into mice, and a second that is harmless. He observed that pathogenic bacteria that have been killed by heating can no longer cause an infection. But when these heat-killed bacteria are mixed with live, harmless bacteria, this mixture is capable of infecting and killing a mouse. What did Griffith conclude from this experiment? A) The infectious strain cannot killed by heating. B) The heat-killed pathogenic bacteria "transformed" the harmless strain into a lethal one. C) The harmless strain somehow revived the heat-killed pathogenic bacteria. D) The mice had lost their immunity to infection with S. pneumoniae.

B) The heat-killed pathogenic bacteria "transformed" the harmless strain into a lethal one.

You prepare bacterial cell extracts by lysing the cells and removing insoluble debris via centrifugation. These extracts provide the proteins required for DNA replication. Your DNA template is a small, double-stranded circular piece of DNA (a plasmid) with a single origin of replication and a single replication termination site. The termination site is on the opposite side of the plasmid from the origin Which of the following statements is TRUE with respect to this in vitro replication system? Figure 6-11 A) There will be only one leading strand and one lagging strand produced using this template. B) The leading and lagging strands compose one half of each newly synthesized DNA strand. C) The DNA replication machinery can assemble at multiple places on this plasmid. D) One daughter DNA molecule will be slightly shorter than the other.

B) The leading and lagging strands compose one half of each newly synthesized DNA strand.

The tryptophan operator A) is an allosteric protein. B) binds to the tryptophan repressor when the repressor is bound to tryptophan. C) is required for production of the mRNA encoded by the tryptophan operon. D) is important for the production of the tryptophan repressor.

B) binds to the tryptophan repressor when the repressor is bound to tryptophan.

How are most eukaryotic transcription regulators able to affect transcription when their binding sites are far from the promoter? A) by binding to their binding site and sliding to the site of RNA polymerase assembly B) by looping out the intervening DNA between their binding site and the promoter C) by unwinding the DNA between their binding site and the promoter D) by attracting RNA polymerase and modifying it before it can bind to the promoter

B) by looping out the intervening DNA between their binding site and the promoter

Which of the following statements about iPS cells is FALSE? A) iPS cells can be made by adding a combination of transcription regulators to a fibroblast. B) iPS cells made from mouse cells can differentiate into almost any human cell type. C) Stimulation by extracellular signal molecules causes iPS cells to differentiate. D) A cell that is dedifferentiated to become an iPS cell will undergo changes to its gene expression profile.

B) iPS cells made from mouse cells can differentiate into almost any human cell type.

Combinatorial control of gene expression A) involves every gene using a different combination of transcriptional regulators for its proper expression. B) involves groups of transcription regulators working together to determine the expression of a gene. C) involves only the use of gene activators used together to regulate genes appropriately. D) is seen only when genes are arranged in operons.

B) involves groups of transcription regulators working together to determine the expression of a gene.

The distinct characteristics of different cell types in a multicellular organism result mainly from the differential regulation of the A) ion of specific genes. B) transcription of genes transcribed by RNA polymerase II. C) transcription of housekeeping genes. D) proteins that directly bind the TATA box of eukaryotic genes.

B) transcription of genes transcribed by RNA polymerase II.

A finished draft of the human genome was published in A) 1965. B) 1984. C) 2004. D) 2018.

C) 2004.

Figure 7-3 shows a ribose sugar. The part of the ribose sugar where a new ribonucleotide will attach in an RNA molecule is pointed to by arrow A) 1. B) 3. C) 4. D) 5.

C) 4.

Figure 7-3 shows a ribose sugar. The part of the ribose sugar that is different from the deoxyribose sugar used in DNA is pointed to by arrow A) 1. B) 4. C) 5. D) 6.

C) 5.

Which of the following changes is least likely to arise from a point mutation in a regulatory region of a gene? A) A mutation that changes the time in an organism's life during which a protein is expressed. , Not Selected B) A mutation that eliminates the production of a protein in a specific cell type. C) A mutation that changes the subcellular localization of a protein. D) A mutation that increases the level of protein production in a cell.

C) A mutation that changes the subcellular localization of a protein.

Two individuals are represented in each choice in Figure 9-42; individual 1 is one of the parents of individual 2. The asterisk seen in each choice indicates the occurrence of a single mutation during the cell division. Which of the choices in Figure 9-42 will lead to a mutation in every cell of the individual in which the original mutation occurred? Figure 9-42 A) A B) B C) C D) D

C) C

The MyoD transcriptional regulator is normally found in differentiating muscle cells and participates in the transcription of genes that produce muscle-specific proteins, such as those needed in contractile tissue. Amazingly, expression of MyoD in fibroblasts causes these cells derived from skin connective tissue to produce proteins normally only seen in muscles. However, some other cell types do not transcribe muscle-specific genes when MyoD is expressed in them. Which of the following statements below is the best explanation of why MyoD can cause fibroblasts to express muscle-specific genes? A) Unlike some other cell types, fibroblasts have not lost the muscle-specific genes from their genome. B) The muscle-specific genes must be in heterochromatin in fibroblasts. C) During their developmental history, fibroblasts have accumulated some transcriptional regulators in common with differentiating muscle cells. D) The presence of MyoD is sufficient to activate the transcription of muscle-specific genes in all cell types.

C) During their developmental history, fibroblasts have accumulated some transcriptional regulators in common with differentiating muscle cells

Which DNA base pair is represented in furgures 5-7? A) A-T B)T-A C) G-C D) C-G

C) G-C

Which of the following statements about nucleosomes is TRUE? A) nucleosomes activate transcription when bound to the promoter. B) Although RNA polymerase can access DNA packed within nucleosomes, the general transcription factors and transcriptional regulators cannot. C) Histone acetyltransferases affect transcription by both altering chromatin structure to allow accessibility to the DNA and by adding acetyl groups to histones that can bind proteins that promote D) Histone deacetylases remove lysines from histone tails.

C) Histone acetyltransferases affect transcription by both altering chromatin structure to allow accessibility to the DNA and by adding acetyl groups to histones that can bind proteins that promote

Which of the following statements about the proteasome is FALSE? A) Ubiquitin is a small protein that is covalently attached to proteins to mark them for delivery to the proteasome. B) Proteases reside in the central cylinder of a proteasome. C) Misfolded proteins are delivered to the proteasome, where they are sequestered from the cytoplasm and can attempt to refold. D) The protein stoppers that surround the central cylinder of the proteasome use the energy from ATP hydrolysis to move proteins into the proteasome inner chamber.

C) Misfolded proteins are delivered to the proteasome, where they are sequestered from the cytoplasm and can attempt to refold.

Operons A) found in eukaryotic cells. B)are transcribed by RNA polymerase II. C) contain a cluster of genes transcribed as a single mRNA. D) can only be regulated by gene activator proteins.

C) contain a cluster of genes transcribed as a single mRNA.

DNA replication is considered semiconservative because A) after many rounds of DNA replication, the original DNA double helix is still intact. B) each daughter DNA molecule consists of two new strands copied from the parent DNA molecule. C) each daughter DNA molecule consists of one strand from the parent DNA molecule and one new strand. D) new DNA strands must be copied from a DNA template.

C) each daughter DNA molecule consists of one strand from the parent DNA molecule and one new strand.

A neuron and a white blood cell have very different functions. For example, a neuron can receive and respond to electrical signals, while a white blood cell defends the body against infection. This is because A) all of the proteins found in a neuron are completely different from the proteins found in a white blood cell. B) the neuron and the white blood cell within an individual have the same genome. C) the neuron expresses some mRNAs that the white blood cell does not. D) neurons and white blood cells are differentiated cells and thus no longer need to transcribe and translate genes.

C) the neuron expresses some mRNAs that the white blood cell does not.

which of the following is NOT normally observed in a DNA duplex? A) purine-pyrimidine pairs B) external sugar-phosphate backbone C) uniform left-handed twist D) antiparralel strands

C) uniform left-handed twist

In principle, how many different cell types can an organism having four different types of transcription regulators and thousands of genes create? A) up to 4 B) up to 8 C) up to 16 D) thousands

C) up to 16

Which of the following DNA strands can form a DNA duplex by pairing with itself at each position? A) 5´-AAGCCGAA-3´ B) 5´-AAGCCGTT-3´ C) 5´-AAGCGCAA-3´ D) 5´-AAGCGCTT-3´

D) 5´-AAGCGCTT-3´

Which of the following is the least likely to be a selectively neutral mutation? (The codon table in Figure 9-14 will help you answer this question.) A) A mutation that deletes 50% of a pseudogene. B) A mutation that changes the CCC codon to the CCT codon in a protein-coding gene. C) A mutation that changes the TCC codon to the AGT codon in a protein-coding gene. D) A mutation that changes the TAT codon to the TAG codon in a protein-coding gene.

D) A mutation that changes the TAT codon to the TAG codon in a protein-coding gene.

Which diagram accurately represents the directionality of DNA strands at one side of a replication fork? Figure 6-19 A) Diagram A B) Diagram B C) Diagram C D) Diagram D

D) Diagram D

If the genome of the bacterium E. coli requires about 20 minutes to replicate itself, how can the genome of the fruit fly Drosophila be replicated in only 3 minutes? A) The Drosophila genome is smaller than the E. coli genome. B)Eukaryotic DNA polymerase synthesizes DNA at a much faster rate than prokaryotic DNA polymerase. C) The nuclear membrane keeps the Drosophila DNA concentrated in one place in the cell, which increases the rate of polymerization. D) Drosophila DNA contains more origins of replication than E. coli DNA.

D) Drosophila DNA contains more origins of replication than E. coli DNA.

The octameric histone core is composed of four different histone proteins, assembled in a stepwise manner. Once the core octamer has been formed, DNA wraps around it to form a nucleosome core particle. Which of the following histone proteins does NOT form part of the octameric core? A) H4 B) H2A C) H3 D) H1

D) H1

Which of the following functions do you NOT expect to find in the set of genes found in all organisms on Earth? A) DNA replication B) DNA repair C) protein production D) RNA splicing

D) RNA splicing

Figure 9-12 shows the evolutionary history of the globin gene family members. Given this information, which of the following statements is TRUE? A) The ancestral globin gene arose 500 million years ago. B) The α-globin gene is more closely related to the ε-globin gene than to the δ-globin gene. C) The nucleotide sequences of the two γ-globins will be most similar because they are the closest together on the chromosome. D) The fetal β-globins arose from a gene duplication that occurred 200 million years ago, which gave rise to a β-globin expressed in the fetus and a β-globin expressed in the adult.

D) The fetal β-globins arose from a gene duplication that occurred 200 million years ago, which gave rise to a β-globin expressed in the fetus and a β-globin expressed in the adult.

(Q013) You prepare bacterial cell extracts by lysing the cells and removing insoluble debris via centrifugation. These extracts provide the proteins required for DNA replication. Your DNA template is a small, double-stranded circular piece of DNA (a plasmid) with a single origin of replication and a single replication termination site. The termination site is on the opposite side of the plasmid from the origin. Figure 6-11 What part of the DNA replication process would be most directly affected if a strain of bacteria lacking the exonuclease activity of DNA polymerase were used to make the cell extracts? A) initiation of DNA synthesis B) Okazaki fragment synthesis C) leading-strand elongation D) lagging-strand completion

D) lagging-strand completion

You prepare bacterial cell extracts by lysing the cells and removing insoluble debris via centrifugation. These extracts provide the proteins required for DNA replication. Your DNA template is a small, double-stranded circular piece of DNA (a plasmid) with a single origin of replication and a single replication termination site. The termination site is on the opposite side of the plasmid from the origin. What part of the DNA replication process would be most directly affected if a strain of bacteria lacking DNA ligase were used to make the cell extracts? A) nitiation of DNA synthesis B) Okazaki fragment synthesis C) leading-strand elongation D) lagging-strand completion

D) lagging-strand completion

Which of the following is NOT a general mechanism that cells use to maintain stable patterns of gene expression as cells divide? A) a positive feedback loop, mediated by a transcriptional regulator that activates transcription of its own gene in addition to other cell-type-specific genes B) faithful propagation of condensed chromatin structures as cells divide C) inheritance of DNA methylation patterns when cells divide D) proper segregation of housekeeping proteins when cells divide

D) proper segregation of housekeeping proteins when cells divide

Which of the following chemical groups is NOT used to construct a DNA.molecule? A) five carbon sugar B) phosphate C) nitrogen-containing base D) six-carbon sugar

D) six-carbon sugar

Which of the following statements is FALSE? A) molecule's synthesis is completed. B) If two genes are to be expressed in a cell, these two genes can be transcribed with different efficiencies. C) RNA polymerase is responsible for both unwinding the DNA helix and catalyzing the formation of the phosphodiester bonds between nucleotides. D)Unlike DNA, RNA uses a uracil base and a deoxyribose sugar.

D)Unlike DNA, RNA uses a uracil base and a deoxyribose sugar.