unit 6 genetic expression & regulation
The following questions refer to DNA strand bacteria and table of codons dna 3' TAG TTC AAA CCG AAC ATT 5'
5' AUC AAG UUU GGC UUG UAA 3'
Which of the following does not occur in prokaryotic gene expression, but does occur in eukaryotic gene expression?
A cap is added to the 5' end of the mRNA.
a mutation that inactivates a regulatory gene of a repressible operon in an e. coli cell would result to
Continuous transcription of the structural gene controlled by that regulator
which of the following best summarizes the flow of information required for the synthesis of proteins embodied in the genome in a
DNA to RNA to protein
Which of the following particular characteristics of DNA replication causes the leading strand to be constructed more quickly than the lagging strand?
During replication, DNA can only be built in a 5' to 3' direction.
Cystic Fibrosis is a recessively inherited disorder that results from a mutation in the gene encoding CFTR chloride ion channels located om the surface of many epithelial cells. AS shown in the figure, the mutation prevents the normal of chloride ions from the cytosol of the cell to the extra cellular fluid. As a consequence of the mutation, the mucus layer that is normally present on the surface of the cells becomes exceptionally dehydrated and viscous. An answer to which of the following questions would provide the most information about the association between the CFTR mutation and viscous mucus?
How does the disrupted chloride movement affect the movement of sodium ions and water by the cell?
The trp operon is a coordinately regulated group of genes (trpA-trpE) that are required for tryptophan biosynthesis in E.coli. Based on the figure below, which of the following correctly describes the regulation of the trp operon?
In the presence of tryptophan, the repressor is active and binds to the trp operator, preventing RNA polymerase from transcribing the operon
A model of a process involving nucleic acids which of the following best explains what process is represented in figure 1
New DNA strands are being synthesized in the 5' to 3' direction using their DNA templates.
Which of the following best describes a characteristic of DNA that makes it useful as hereditary material?
Nucleotide bases in one strand can only be paired with specific bases in the other strand
One of the major advantages of transforming bacteria with a plasmid that contains DNA of interest is to amplify the DNA.
Polymerase chain reaction
Fluorescent genes from a jellyfish can be inserted into bacteria with minor modifications, resulting in bacteria that can produce green fluorescent protein.
Prokaryotes and eukaryotes use the same codons for translation.
Replication in prokaryotes differs from replication in eukaryotes for which of the following reasons?
Prokaryotic chromosomes have a single origin of replication, whereas eukaryotic chromosomes have many.
Which of the following statements best describes the termination of transcription in prokaryotes?
RNA polymerase transcribes through the terminator sequence, causing the polymerase to separate from the DNA and release the transcript.
Which of the following best explains how continuity of genetic information in cells is ensured across generations?
Replication uses a parental strand of DNA as a template to create a new strand of DNA
Sickle-cell anemia is an inherited blood disorder in which one of the hemoglobin subunits is replaced with a different form of hemoglobin. Partial DNA sequences of the HBB gene for normal hemoglobin and for sickle-cell hemoglobin are shown in Figure 1. Which of the following best describes the type of mutation shown in Figure 1 that leads to sickle-cell anemia?
Substitution
what is by the description "antiparallel" regarding the strands the make up DNA
The 5' to 3' direction of the other strand runs counter to the 5' to 3' direction of the other strand.
The figure above depicts the DNA-protein complex that is assembled at the transcriptional start site of gene X when the expression of gene X is activated in the liver cells... which of the following most likely contributes to the specific expression pattern of gene X.
The activator is a sequence-specific DNA-binding protein that is present in some tissues but not in other tissues.
Arctic foxes typically have a white coat in the winter. In summer, when there is no snow on the ground, the foxes typically have a darker coat. Which of the following is most likely responsible for the seasonal change in coat color?
The decrease in the amount of daylight in winter causes a change in gene expression, which results in the foxes growing a lighter- appearing coat.
prokaryotes use operons to control gene expression. one specific operon the lac operon in this mechanism, which of the following statements best describes the role of cAMP in the expression of the lac operon.
______ cAMP (multiple choice A)
what method is utilized by eukaryotes to control their gene expression that is NOT used in bacteria?
control of both RNA splicing and chromatin remodeling
A lack of which molecule would result in a cell's inability to "turn off" genes
corepressor
which of the following best describes how sticklebacks in the same population with identical copies of Pux 1 gene can still show phenotypic variation in the pelvic spine character?
expression of the pux 1 gene can be affected by mutations at another genetic locus
A nonsense mutation in a gene:___
introduces a premature stop codon into the mRNA
Once researchers identified DNA as the unit of inheritance, they asked how information was transferred from the DNA in the nucleus to the site of protein synthesis in the cytoplasm. What is the mechanism of information transfer in eukarotes?
messenger RNA is transcribed from a single gene and transfers information from the DNA in the nucleus to the cytoplasm, where protein synthesis takes place.
One strand of a DNA molecule has the following sequence: 3-AGTACAAACTATCCACCGTC-5. In order for transcription to occur in that strand, there would have to be a specific recognition sequence, called a(n) __________, to the left of the DNA sequence indicated.
promoter
Lactose digestion in E. coli begins with its hydrolysis by the enzyme b-galactosidase. The gene encoding b-galactosidase, lacZ, is part of a coordinately regulated operon containing other genes required for lactose utilization. Which of the following figures correctly depicts the interactions at the lac operon when lactose is NOT being utilized? (The legend below defines the shapes of the molecules illustrated in the options.)
promoter operator(repressor protein) structural genes
researchers studying new viruses analyzed the genetic material found in four different virus samples to determine the percent nitrogen base composition of each virus. The data are shown in the table. which of the following samples most likely contains a double-stranded RNA virus?
sample 1
a scientist adds a chemical to a culture of dividing cells in order to disrupt DNA replication. The replicated DNA produced by the cells to double-strand but sections of a lack of covalent bonds between adjacent nucleotides. which of the following claims is best supported by the data
the chemical inhibits DNA ligase
which of the following summarizes of protein synthesis is correct?
the mRNA is made on a DNA template and then amino acid bearing DNA bind to a through codon anticodon pairing
protoporphyria is a genetic disorder characterized by an extreme sensitivity to sunlight. One form of protoporphyria is caused by a mutation in the ALAS 2 gene that results in the accumulation of protoporphyria, an organic compound, in the liver, and skin. the pedigree in figure 1 shows the incidence of protoporphyria in a particular family which of the following best explains why
the mutation introduces a premature stop codon, causing translation to end early.
which of the following best describes a characteristic of the process shown in figure 1 that in unique to prokaryotes
the translation of the mRNA is occurring while the RNA is still being transcribed
which of the following is the function of the process shows which occurs during eukaryotic protein synthesis
unnecessary segments of mRNA transcript are being removed prior to the start of transcription
