Exam 2 Practice
Where is the white gene found on the drosophila? A. X B. 1 C. 18 D. Y
X
Which chromosome is the most dense chromosome in the human genome? A. Y B. X C. Chromosome 1 D. Chromosome 21
X
Which is not true of mobile genetic elements (MGEs)? A. MGEs can serve as targets of homologous recombination, resulting in DNA duplication and deletion B. MGEs can disrupt a gene's coding sequences but not its expression level C. MGEs can occasionally rearrange neighboring DNA sequences of the host genome, moving exons from one position to another D. MGEs are present in bacteria as well as eukaryotes
MGEs are present in bacteria as well as eukaryotes
At a replication fork, the leading strand is synthesized: A. continuously. B. discontinuously. C. first. D. when the lagging strand is complete.
continuously.
At a replication fork, the lagging strand is synthesized: A. continuously. B. discontinuously. C. first. D. when the leading strand is complete.
discontinuously.
What type of enzyme fills in the gap after damaged DNA has been removed? A. Polymerase B. Nuclease C. Primase D. Ligase E. Helicase
Polymerase
Tandem copies of a gene are found in the genome. A. mutation within a gene B. gene duplication C. mutation in a regulatory region D. exon shuffling E. horizontal gene transfer
gene duplication
A copy of a bacterial gene is now found integrated on a human chromosome. A. mutation within a gene B. gene duplication C. mutation in a regulatory region D. exon shuffling E. horizontal gene transfer
horizontal gene transfer
No mismatch repair
proofreading failed
Which base pairs are found in DNA? A. A-C and T-G B. A-T and C-G C. A-G and C-T D. A-U and C-G
A-T and C-G
Conjugation is the transfer of genetic information from one cell to another through a sex pilus (sex between bacteria). The result is: A. vertical gene transfer B. horizontal gene transfer C. genetic recombination without reproduction D. A and C E. B and C
B and C
__________ are regions of the chromosomes that contain genes but become heterochromatic depending on the cell type. A. Constitutive heterochromatin B. Facultative heterochromatin C. euchromatin D. centromere
Facultative heterochromatin
What is the largest gene in the human genome? A. Human β-globin gene B. Human Factor VIII gene C. Human Factor IV gene D. Human Dystrophin gene
Human Dystrophin gene
What type of bond connects base pairs? A. Covalent bond B. Ionic bond C. Hydrogen bond
Hydrogen bond
How does ultraviolet radiation in sunlight typically damage DNA A. It breaks hydrogen bonds between the two strands of DNA. B. It removes bases from nucleotides in DNA. C. It promotes covalent linkage between two adjacent pyrimidine bases.
It promotes covalent linkage between two adjacent pyrimidine bases.
You have discovered an "Exo-" mutant form of DNA polymerase in which the 3'-to-5' exonuclease function has been destroyed but the ability to join nucleotides together is unchanged. Which of the following properties do you expect the mutant polymerase to have? A. It will polymerize in both the 5'-to-3' direction and the 3'-to-5' direction. B. It will polymerize more slowly than the normal Exo+ polymerase. C. It will fall off the template more frequently than the normal Exo+ polymerase. D. It will be more likely to generate mismatched base pairs.
It will be more likely to generate mismatched base pairs.
What type of enzyme seals the newly added (repaired DNA) to the rest of the DNA molecule? A. Polymerase B. Nuclease C. Primase D. Ligase E. Sealicase
Ligase
While observing the repeated sequences of bovine and E. Coli DNA, we see a varying C0t. What does a low C0t value means? A. Repetitive sequences and reassociate faster B. Repetitive sequences and reassociate slower C. Unique sequences and reassociate faster D. Unique sequences and reassociate slower
Repetitive sequences and reassociate faster
Which human chromosomes do NOT have constitutive heterochromatin? A. 18 B. 1 C. 16 D. 9 E. Y
18
Reverse transcriptase produces DNA copies using: A. DNA as a template. B. RNA as a template. C. a viral genome as a template. D. transposase as a template.
RNA as a template.
HNPCC is caused by defects in __________, which codes for DNA mismatch repair proteins. A. MutS B. MutL C. MutE D. A and B E. B and C
A and B
What completes the mismatched repair? A. DNA polymerase B. DNA ligase C. GAP D. A and B E. A and C
A and B
Which of the following statements about gene families is false? A. Because gene duplication can occur when crossover events occur, genes are always duplicated onto homologous chromosomes. B. Not all duplicated genes will become functional members of gene families. C. Whole genome duplication can contribute to the formation of gene families. D. Duplicated genes can diverge in both their regulatory regions and their coding regions.
Because gene duplication can occur when crossover events occur, genes are always duplicated onto homologous chromosomes.
When does DNA polymerase perform its proofreading function on mispaired nucleotides? A. Before adding the next nucleotide in the chain B. After adding a stretch of about 100 more nucleotides C. After finishing the DNA strand
Before adding the next nucleotide in the chain
Mismatch repair G=>T
incorrect
A protein normally expressed only in the liver is now expressed in blood cells. A. mutation within a gene B. gene duplication C. mutation in a regulatory region D. exon shuffling E. horizontal gene transfer
mutation in a regulatory region
The process of DNA replication requires that each of the parental DNA strands be used as a ___________________ to produce a duplicate of the opposing strand. A. catalyst B. competitor C. template D. copy
template
In X.laevis a whole genome duplication occurred, resulting in a: A. diploid species B. triploid species C. tetraploid species
tetraploid species
On a DNA strand that is being synthesized, which end is growing? A. the 3' end B. the 5' end C. both ends
the 3' end
DNA synthesis begins at: A. the telomeres. B. the centromere. C. the replication origins. D. the CpG islands.
the replication of origins
Decondensation is necessary for: A. Transcription B. Translation C. Meiosis D. Mitosis
transcription
What does the image show? A. Insertion of simple bacteria transposons B. Non-replicative Transposition C. Replicative Transposition D. A and B E. A and C
A and B
Which of the following would be seen in the interphase stage of the cell cycle? A. Euchromatin B. Intact nuclear envelope C. Compact visible chromatin D. A and B E. All of the above
A and B
E. coli DNA reassociation curve has only one component. Therefore: A. all the sequences are unique B. all the DNA is repetitive C. all the DNA is non-repetitive D. A and B E. A and C
A and C
What does the image show? A. Insertion of simple bacteria transposons B. Non-replicative Transposition C. Replicative Transposition D. A and B E. A and C
A and C
The G-C base pair has less density than the A-T base pair. A. True B. False
False
Hypoxanthine pairs with: A. uracil B. thymine C. guanine D. cytosine E. None of the above
cytosine
Your mom gives you a viral infection. How? A. vertical transfer B. horizontal transfer C. looking at you D. all of the above
horizontal transfer
A __________ in patients with inherited ataxia causes a piece of chromosome 4 to become inappropriately attached to chromosome 12. A. relocation B. inversion C. transposition
transposition
Cytosine deamination produces: A. uracil B. thymine C. guanine D. hypoxanthine E. Adenine
uracil
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 progeny. C. In an evolutionary sense, somatic cells exist only to help propagate germline cells. D. A mutation is passed on to offspring only if it is present in the germ line.
A mutation that arises in a mother's somatic cell often causes a disease in her daughter.
What enzyme is NOT used in first step of base excision repair? A. DNA polymerase B. DNA glycosylase C. endonuclease D. deoxyribosephosphodiesterase E. All of the above are used.
DNA polymerase
Proofreading: A. DNA polymerase has 3' to 5' exonuclease activity B. DNA polymerase has 5' to 3' exonuclease activity C. DNA polymerase has 3' to 5' endonuclease activity D. DNA polymerase has 5' to 3' endonuclease activity
DNA polymerase has 3' to 5' exonuclease activity
__________ establish new DNA methylation patterns during development, or in response to external cues such as the environment, behavior, or diet. A. De novo methyltransferases B. Maintenance methyltransferases C. DNA methyltransferases
De novo methyltransferases
Royal jelly silences the expression of: A. oct4 B. Sox2 C. klf4 D. Dnmt3
Dnmt3
What transcription regulator is NOT found in the cultured mouse fibroblast? A. oct4 B. Sox2 C. klf4 D. Dnmt3
Dnmt3
In the present day organisms, which trait or gene is commonly acquired by horizontal gene transfer? A. lactose tolerance B. Drug resistance C. Sickle cell anemia D. Halitosis
Drug resistance
In eukaryotes, where do transcription regulators bind? A. Upstream from a gene B. Downstream from a gene C. Either upstream or downstream from a gene D. The TATA box
Either upstream or downstream from a gene
Which statement is FALSE? A. Non-genetic cellular memory is the basis of epigenetic. B. Epigenetics is the study of genetic changes and variations in phenotypes that are potentially heritable. C. Epigenetics are caused by permanent changes in DNA base sequences. D. All of the above are true.
Epigenetics are caused by permanent changes in DNA base sequences.
Which of the following is NOT true? A. Exon shuffling allows the generation of hybrid proteins with new functions B. Exon shuffling allows bacteria to become antibiotic resistant C. All human proteins are thought to have arisen from the duplication and shuffling of a few thousand exons D. Exon shuffling requires the presence of introns
Exon shuffling allows bacteria to become antibiotic resistant
Transcription regulators can be used to convert one differentiated cell type into another cell type, but NOT to convert differentiated cells into a less differentiated, pluripotent stem cells. A. True B. False
False
The polarity in a DNA strand is indicated by referring to one end as the 3′ end and the other as the 5′ end. Which structure is on the 3′ end? A. Hydroxyl group B. Phosphate group C. Nitrogenous base
Hydroxyl group
Your friend works in a lab that is studying why a particular mutant strain of Drosophila grows an eye on its wing. Your friend discovers that this mutant strain of Drosophila is expressing a transcription factor incorrectly. In the mutant Drosophila, this transcription factor, which is normally expressed in the primordial eye tissue, is now misexpressed in the wing primordial wing tissue, thus turning on transcription of the set of genes required to produce an eye in the wing primordial tissue. If this hypothesis is true, which of the following types of genetic change would most likely lead to this situation? A. a mutation within the transcription factor gene that leads to a premature stop codon after the third amino acid B. a mutation within the transcription factor gene that leads to a substitution of a positively charged amino acid for a negatively charged amino acid C. a mutation within an upstream enhancer of the gene D. a mutation in the TATA box of the gene
a mutation within an upstream enhancer of the gene
Sickle-cell anemia is an example of an inherited disease. Individuals with this disorder have misshapen (sickle-shaped) red blood cells caused by a change in the sequence of thenBeta-globin gene. What is the nature of the change? A. chromosome loss B. base-pair change C. gene duplication D. base-pair insertion
base-pair change
A protein acquires a DNA binding domain. A. mutation within a gene B. gene duplication C. mutation in a regulatory region D. exon shuffling E. horizontal gene transfer
exon shuffling
The image shows a: A. mutation within a gene B. gene duplication C. mutation in a regulatory region D. exon shuffling E. horizontal gene transfer
gene duplication
DNA polymerase catalyzes the joining of a nucleotide to a growing DNA strand. Whatprevents this enzyme from catalyzing the reverse reaction? A. hydrolysis of PPi to Pi + Pi B. release of PPi from the nucleotide C. hybridization of the new strand to the template D. loss of ATP as an energy source
hydrolysis of PPi to Pi + Pi
Adenine deamination produces: A. uracil B. thymine C. guanine D. hypoxanthine E. cytosine
hypoxanthine
DNA synthesis proceeds: A. in 5′ to the 3′ direction. B. in the 3′ to 5′ direction. C. in both directions at once. D. from the centromeres to the telomeres.
in 5′ to the 3′ direction.
The replication forks at an origin of replication move: A. in the same direction. B. in opposite directions. C. toward the origin. D. in the 5′ to 3′ direction.
in opposite directions
Several members of the same family were diagnosed with the same kind of cancer whenthey were unusually young. Which one of the following is the most likely explanation forthis phenomenon? It is possible that the individuals with the cancer have_______________________. A. inherited a cancer-causing gene that suffered a mutation in an ancestor's somatic cells B. inherited a mutation in a gene required for DNA synthesis C. inherited a mutation in a gene required for mismatch repair D. inherited a mutation in a gene required for the synthesis of purine nucleotides
inherited a mutation in a gene required for mismatch repair
The image shows a: A. mutation within a gene B. gene duplication C. mutation in a regulatory region D. exon shuffling E. horizontal gene transfer
mutation in a regulatory region
A protein becomes much more unstable. A. mutation within a gene B. gene duplication C. mutation in a regulatory region D. exon shuffling E. horizontal gene transfer
mutation within a gene
A protein normally localized in the nucleus is now localized in the cytoplasm. A. mutation within a gene B. gene duplication C. mutation in a regulatory region D. exon shuffling E. horizontal gene transfer
mutation within a gene
The image shows a: A. mutation within a gene B. gene duplication C. mutation in a regulatory region D. exon shuffling E. horizontal gene transfer
mutation within a gene
MyoD commits cells to become: A. myoblasts. B. nucleus. C. myotubes. D. muscle fibers.
myoblasts.
Gene duplication usually results in: A. horizontal transfer B. vertical transfer C. new gene families D. None of the above
new gene families
The __________ is the region of the nucleus where the transcription of rRNAgenes and the assembly of ribosomes occur. A. mitochondrion B. nucleolus C. cytosol D. telomere
nucleolus
Each chromosome contains: A. one long DNA molecule. B. one long RNA molecule. C. one long sequence of amino acids. D. a single gene for a protein.
one long DNA molecule
Nucleotides are linked by: A. hydrogen bonds. B. phosphodiester bonds. C. peptide bonds. D. ionic bonds.
phosphodiester bonds
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. E. number of strands in the helix.
ratio of A + T to G + C.
Related genes my take very different developmental pathways due to differences in the: A. regulatory regions B. gene family C. introns D. exons
regulatory regions
In Eukaryotes, individual protein domains are generally encoded by single ________. A. exons B. introns C. genes D. inverted repleats
exons
The proofreading activity of DNA polymerase occurs in which direction? A. 5′ to 3′ B. 3′ to 5′
3' to 5'
Label the image.
A. Nuclear Envelope B. Heterochromatin C. Nucleolus
Which histone modification would promote gene expression? A. Acetylation of lysines B. Methylation of arginines C. Methylation of lysines D. Acetylation of arginines E. None of the above
Acetylation of lysines
Exons: A. Coding sequences B. Non-coding DNA C. untranslated sequences at the 3' and 5' ends D. untranslated sequences at the 5' and 3' ends
Coding sequences
Simple sequence repeats do NOT cluster here: A. Centromere B. Telomere C. All of the above D. None of the above
None of the above
The human genome contains approximately how many genes? A. 46 B. 30,000 C. 100,000 D. 3,000,000,000
30,000
Over lapping genes are found in: A. ATPase-6 B. ATPase-8 C. Human mitochondria D. All of the above
All of the above
iPS cells are cells induced to differentiate in culture as: A. fat cell B. muscle cell C. neuron D. All of the above
All of the above
Which of the following are transcribed regions? A. Introns B. Exons C. UTRs D. None of the above E. All of the above
All of the above.
Which of the following is true for most genes? A. A gene is a segment of DNA that contains the instructions for making a particular protein. B. A gene is a segment of DNA that contains the instructions for making a particular RNA. C. A gene is a region of DNA that controls a discrete hereditary characteristic of an organism. D. All of the above.
All of the above.
Which of the following is true about the human genome? A. About half the human genome consists of mobile genetic elements. B. About half the human genome consists of genes coding for proteins. C. About half the human genome consists of introns.
About half the human genome consists of mobile genetic elements.
How does the cell know which strand is the newly synthesized strand? A. the recently synthesized strand has breaks B. this strand is interrupted due to discontinuous replication C. Okazaki fragments D. nicks E. All of the above
All of the above
Satellites are: A. Interspersed repeats B. Clustered repeats C. Tandemly repeated DNA D. A and C E. B and C
B and C
Which of the following are genetic changes that contribute to gene evolution? A. Gene alteration does not result in genome evolution. B. Gene duplication. C. Exon shuffling. D. Vertical transfer. E. B and C
B and C
The repair of mismatched base pairs or damaged nucleotides in a DNA strand requires amultistep process. Which choice below describes the known sequence of events in thisprocess? A. DNA damage is recognized, the newly synthesized strand is identified by an existing nick in the backbone, a segment of the new strand is removed by repair proteins, the gap is filled by DNA polymerase, and the strand is sealed by DNA ligase. B. DNA repair polymerase simultaneously removes bases ahead of it andpolymerizes the correct sequence behind it as it moves along the template. DNAligase seals the nicks in the repaired strand. C. DNA damage is recognized, the newly synthesized strand is identified by anexisting nick in the backbone, a segment of the new strand is removed by anexonuclease, and the gap is repaired by DNA ligase. D. A nick in the DNA is recognized, DNA repair proteins switch out the wrong baseand insert the correct base, and DNA ligase seals the nick.
DNA damage is recognized, the newly synthesized strand is identified by anexisting nick in the backbone, a segment of the new strand is removed by repairproteins, the gap is filled by DNA polymerase, and the strand is sealed by DNAligase.
What is the most highly condensed form of chromatin? A. Heterochromatin B. 30-nm chromatin fibers C. Euchromatin
Heterochromatin
Which of the following is NOT true? A. Chinese muntjac have more chromosomes than Indian muntjac B. Chinese muntjac and Indian muntjac can interbreed C. Chinese muntjac and Indian muntjac have almost identical genes D. The hybrid will be able to produce viable offspring
The hybrid will be able to produce viable offspring
Which is NOT an example of epigenetic inheritance? A. The inheritance of methylation patterns in DNA B. The inheritance of a single nucleotide mutation in a gene C. The inheritance of patterns of chromosome condensation D. The inheritance of a regulatory protein that activates its own transcription
The inheritance of a single nucleotide mutation in a gene
What does depurination refer to? A. The loss of A or G bases from DNA B. The lost of T or G bases from DNA C. The breaking of the DNA backbone
The loss of A or G bases from DNA
In our human ancestors, the enzyme lactase, which allows us to digest the milk sugar lactose, was produced only during infancy. Today a portion of the adult population can digest lactose while other adults remain lactose intolerant. Which adults have point mutations in the regulatory DNA of their lactase gene? A. Those who are lactose intolerant B. Those who able to digest lactose
Those who able to digest lactose
A single transcription regulator, if expressed in the appropriate precursor cell, can trigger the formation of a specialized cell type or even an entire organ. A. True B. False
True
Even though control of eukaryotic gene expression is combinatorial, the effect of a single gene regulatory protein can still be decisive in switching any particular gene on or off. A. True B. False
True
Histone tail modifications establish and maintain the different chromatin structures found in heterochromatin and euchromatin. A. True B. False
True
In sexually reproducing organisms, only changes to the germ line are passed along to progeny. A. True B. False
True
Most cancers arise from cells that have accumulated multiple mutations. A. True B. False
True
The position of a gene relative to heterochromatin may affect its expression. A. True B. False
True
Mismatch repair A=>C
correct
The image shows a consequence of: A. deamination B. mismatch repair C. depurination D. radiation-induced mutation
depurination
What type of enzyme removes damaged DNA from the rest of the DNA molecule? A. Polymerase B. Nuclease C. Primase D. Ligase E. Helicase
Nuclease
What structure in an interphase cell contains ribosomal RNA and proteins for the formation of ribosomes? A. Chromatin B. Nucleolus C. Nuclear lamina
Nucleolus
As a percentage, which sequence element makes up the smallest portion of the human genome? A. LINES B. SINES C. Protein coding regions D. Introns E. Simple sequence repeats
Protein coding regions
Which of the following is NOT a mechanism of genetic variation? A. Mutation within the coding sequence of a gene B. Mutation within regulatory DNA of a gene C. Purifying selection D. Gene Duplication and Divergence E. Exon Shuffling
Purifying selection
Which of the following is NOT true about retrotransposons? A. They are unique to eukaryotes. B. They are abundant in the human genome. C. They move via an RNA intermediate. D. They are only found in viruses.
They are only found in viruses.
