GEN EXAM 3 QUIZZES Flashcards
A _______ frequently integrates into the host genome, forming prophages and utilizing a lysogenic cycle to manufacture new phages.
A. eukaryotic cell
B. virulent phage
C. temperate phage
D. bacteria
C. temperate phage
A _______ uses the lytic cycle to begin the immediate manufacture of new phages in the host cells.
A. eukaryotic cell
B. temperate phage
C. virulent phage
D. bacteria
C. virulent phage
What is true in both phage λ and HIV infections?
A. Cell lysis always occurs immediately after virus introduction.
B. There can be a long latent period where no sign of infection, such as cell death, is detectable.
C. Assembled viral particles are always found within the cell.
B. There can be a long latent period where no sign of infection, such as cell death, is detectable.
Which virus uses reverse transcriptase in its reproductive cycle?
A. HIV
B. Phage lambda
C. Both of the viruses use reverse transcriptase
D. Neither of the viruses use reverse transcriptase
A. HIV
Vaccines have been very useful in preventing viral diseases. In fact, they have lead to the eradication of smallpox from the world’s human population. Most vaccines result in the host producing antibodies (proteins that bind to specific amino acid sequences) that bind to specific viral proteins. What might be a reason why a vaccine for HIV has been so difficult to develop?
A. The low mutation rate of HIV
B. The fact that HIV genome is found as both DNA and RNA in a cell
C. The high mutation rate of HIV
D. The HIV virion is coated with cellular proteins
C. The high mutation rate of HIV
What is the genetic material in the T4 bacteriophage?
A. double-stranded RNA
B. single-stranded RNA
C. single-stranded DNA
D. double-stranded DNA
D. double-stranded DNA
Which is a property of emerging viruses?
A. May lead to a significant loss of human life
B. Recent origin
C. More likely to cause infection compared to other strains
D. All of these
D. All of these
If protein was the genetic material of TMV rather than RNA, what would be the result of the Fraenkel-Conrat/Singer experiments when using HR proteins and wild-type RNA?
A. HR type lesions, no histidine and methionine in the capsid protein
B. Wild type lesions, histidine and methionine in the capsid protein
C. Wild type lesions, no histidine and methionine in the capsid protein
D. HR type lesions, histidine and methionine in the capsid protein
D. HR type lesions, histidine and methionine in the capsid protein
You perform an experiment like that performed by Fraenkel-Conrat and Singer on TMV. However, in the first step when the viruses are reconstituted, you decide to add RNase to your HR RNA and wild-type proteins. What will be the content of the newly made viral proteins after the reconstituted virus is placed on leaves?
A. No new viral proteins will be made.
B. The proteins will contain histidine and methionine.
C. The proteins will not contain histidine and methionine.
D. The proteins will contain histidine and methionine, but not as much as HR proteins do.
A. No new viral proteins will be made.
What is the genetic material in the parvovirus?
A. single-stranded RNA
B. double-stranded RNA
C. double-stranded DNA
D. single-stranded DNA
D. single-stranded DNA
The HIV drug fostemsavir binds to glycoprotein gp120, which is a viral envelope protein. Based on what you know about the lifecycle of HIV, with what step do you predict fostemsavir interferes?
A. synthesis of viral components
B. attachment
C. viral assembly
D. entry
E. integration
F. release
B. attachment
A bacteriophage that is physically integrated into the host chromosome is called a ________.
A. prophage
B. heteroduplex
C. envelope phage
D. plaque
A. prophage
What was the outcome of the experiment that reconstituted two different strains of tobacco mosaic viruses that had different infection characteristics?
A. the difference in infection characteristics depended only on the RNA sequence of the virus strain
B. the differences in infection characteristics depended only on the protein coat
C. the differences in infection characteristics depended on an RNA and protein coat interaction
A. the difference in infection characteristics depended only on the RNA sequence of the virus strain
Imagine Rosalind Franklin had performed X-ray diffraction on double-stranded RNA as well as double-stranded DNA. What would be a key difference that she would have observed between these two molecules?
A. DNA double helices are parallel whereas RNA double helices are antiparallel.
B. A DNA helix contains about 10 bp per turn, whereas an RNA helix contains 11 to 12 bp per turn.
C. RNA forms a left-handed helix while DNA forms a right-handed helix.
D. DNA but not RNA forms a helical structure.
B. A DNA helix contains about 10 bp per turn, whereas an RNA helix contains 11 to 12 bp per turn.
The individual(s) who used ball-and-stick models to identify the three-dimensional structure of proteins was _______.
A. Hershey and Chase
B. Chargaff
C. Watson and Crick
D. Franklin
E. Pauling
E. Pauling
Avery, Macleod, and McCarty used the enzyme _______ to remove the proteins from the cell extracts.
A. protease
B. DNase
C. RNase
A. protease
Frederick Griffith is responsible for discovering what process?
A. transformation
B. transmission
C.replication
D. transduction
A. transformation
The purine bases are _______.
A. adenine and guanine
B. cytosine, thymine, and uracil
C. adenine and thymine
D. cytosine and guanine
A. adenine and guanine
The building blocks of DNA are called _________.
A. alleles
B. nucleotides
C. amino acids
D. codons
B. nucleotides
Which RNA structural pattern does NOT contain single-stranded regions?
A. Bulge loop
B. Internal loop
C. Stem-loop
D. Multibranched junction
D. Multibranched junction
The backbone of the DNA molecule is formed by ________.
A. peptide bonds
B. ribose sugars
C. phosphodiester bonds
D. nitrogenous bases
C. phosphodiester bonds
Adenine and thymine form _______ hydrogen bonds between them, while cytosine and guanine form _______ bonds.
A. 4; 3
B. 3; 4
C. 3; 2
D. 2; 3
D. 2; 3
What form of DNA is most common in living organisms?
A. R DNA
B. A DNA
C. Z DNA
D. B DNA
D. B DNA
How many origins of replication are there in a bacterial chromosome?
A. More than two
B. 2
C. 0
D. 1
D. 1
Which of the following is found at the end of a eukaryotic chromosome?
A. kinetochores
B. telomeres
C. centromeres
D. nucleoids
B. telomeres
What is one reason why an amphibian, such as a salamander, might have a larger genome than a mammal, such as a chimpanzee?
A. The amphibian is more complex than the mammal.
B. The amphibian has more repetitive sequences than the mammal.
C. The amphibian has more structural genes than the mammal.
D. The amphibian has more introns than the mammal.
B. The amphibian has more repetitive sequences than the mammal
Where is the bacterial chromosome located?
A. nucleoid
B. nucleolus
C. nucleus
D. nuclear envelope
A. nucleoid
Which statement is true concerning chromosome compaction during cell division?
A. Overall chromosomal length is shortened.
B. Loop domains are not anchored to the scaffolding proteins.
C. Compaction results in increased transcriptional rates.
D. The 30 nm fibers are altered to 60 nm fibers.
A. Overall chromosomal length is shortened.
How many types of histone proteins are there?
A. 7
B. 4
C. 8
D. 5
D. 5
About how many bases of DNA wrap around a histone complex?
A. 200
B. <50
C. >1,000
D. 146
D. 146
The experiment by Noll, 1974, supported the observation that histones were regularly spaced on chromosomes because
A. digestion with low or high amounts of DNase I resulted in a fragment that was found at the bottom of the gel.
B. limited digestion with DNase I resulted in DNA fragments that differed in size by approximately 200 bp.
C. digestion with increased amounts of DNase I resulted in one or a few bands.
D. a digestion performed with a moderate amount of DNase I gave results that were ver
B. limited digestion with DNase I resulted in DNA fragments that differed in size by approximately 200 bp.
A transposon is inserted into the sequence 5’ GACTC 3’. Following simple transposition into this site, what sequences flank the transposon?
A. 5’ GACTC 3’; 5’ GACTC 3’
B. 5’ CTCAG 3’; 5’ CTCAG 3’
C. 5’ CTCAG 3’; 5’ GACTC 3’
D. 5’ GACTC 3’; 5’ CTCAG 3’
A. 5’ GACTC 3’; 5’ GACTC 3’
Which of the following enzymes is required for simple transposition?
A. Integrase
B. Jumpase
C. Transposase
D. Splicase
C. Transposase
According to Chargaff’s rule, if the DNA of a species contains 20% adenine, what percent of guanine will it contain?
A. 50%
B. 75%
C. 20%
D. 30%
D. 30%
The individuals who determined that Griffith’s transforming principle was DNA were __________.
A. Watson and Crick
B. Hershey and Chase
C. Creighton and McClintock
D. Avery, Macleod, and McCarty
D. Avery, Macleod, and McCarty
Choose the RNA molecule that would be complementary to this DNA molecule: 5’-TTAACCGG-3’.
A. 5’-UUAACCGG-3’
B. 5’-AAUUGGCC-3’
C. 3’-AATTGGCC-5’
D. 3’-AAUUGGCC-5’
D. 3’-AAUUGGCC-5’
The fact that the two DNA strands are arranged in opposite orientations gives DNA its _____ characteristics.
A. antiparallel
B. water-soluble
C. redundant
D. complementary
A. antiparallel
How many bases are necessary to complete one complete twist (360 degrees) of a DNA double helix?
A. 100
B. 5
C. 10
D. 1000
C. 10
Human chromosome 3 is almost 200 million base pairs in length. How many origins of replication do you predict will be found on human chromosome 3?
A. 200,000
B. 1
C. 20,000
D. 2,000
E. 2
D. 2,000
Topoisomerase I does which of the following?
A. relax negative supercoils
B. introduce negative supercoils
C. More than one of these choices are correct.
D. relieve positive supercoils
A. relax negative supercoils
The correct order of compaction from least compacted to most compacted would be
A. naked DNA, nucleosome, 30 nm fiber, loop, metaphase chromosome.
B. naked DNA, loop, 30 nm fiber, nucleosome, metaphase chromosome.
C. naked DNA, 30 nm fiber, nucleosome, loop, metaphase chromosome.
D. naked DNA, metaphase chromosome, loop, 30 nm fiber, nucleosome.
A. naked DNA, nucleosome, 30 nm fiber, loop, metaphase chromosome.
A double stranded stretch of eukaryotic DNA is 4,000 bp long. If the average linker is about 54 base pairs, how many molecules of histone H3 would be present on this piece of DNA?
A. 40
B. 74
C. 20
D. 148
A. 40
Areas of the chromosome that are highly condensed and transcriptionally inactive are called
A. superchromatin.
B. euchromatin.
C. exons.
D. heterochromatin.
D. heterochromatin.
The zigzag model is associated with the _______ level of DNA organization.
A. 30 nm fiber
B. scaffold protein
C. histone
D. 11nm fiber
E. beads-on-a-string
A. 30 nm fiber
Which of the following is technically NOT part of the genetic information of a transposable element?
A. inverted repeats
B. direct repeats
C. insertion elements
D. transposase
B. direct repeats
Consider a simple transposition event in a region of the genome where DNA replication is not actively occurring. At the end of the event how many copies of this transposon will be present in the genome?
A. 4
B. 2
C. There is not enough information given to determine how many transposons will be present.
D. 1
D. 1
The researcher(s) who initially used X-ray diffraction to gather information on the DNA molecule was ______.
A. Hershey and Chase
B. Franklin
C. Pauling
D. Chargaff
E. Watson and Crick
B. Franklin
The _______ was/were labeled using the radioisotope 32P in the Hershey-Chase experiments.
A. carbohydrates
B. RNA
C. DNA
D. proteins
C. DNA
These individuals determined that DNA was the genetic material in T2 phage.
A. Creighton and McClintock
B. Avery, Macleod, and McCarty
C. Watson and Crick
D. Hershey and Chase
D. Hershey and Chase
How is the directionality of a DNA molecule described based on the orientation of sugar molecules within the strand?
A. left to right
B. top to bottom
C. A to T or G to C
D. All DNA molecules are different in their directionality.
E. 5′ to 3′
E. 5′ to 3′
How many total hydrogen bonds would be found holding together the base pairs in a double stranded DNA molecule containing the following nucleotides:
5’-TAGCCCTT-3’
3’-ATCGGGAA-5’
A. 16
B. 20
C. 8
D. 24
B. 20
Unique sequences make up approximately what percent of the human genome?
A. 40%
B. 80%
C. 25%
D. 5%
A. 40%
What is a nucleosome composed of?
A. Two turns of DNA wrapped around an octet core of histone proteins.
B. DNA wrapped twice around a histone octet and includes approximately 200 bases that are not associated with the histones.
C. It is composed of 2 copies each of H2A, H2B, H3, and H4 and 1 copy of H1.
D. Two copies each of H2A, H2B, H3, and H4.
A. Two turns of DNA wrapped around an octet core of histone proteins.
The formation of what structure would be impaired if a cell was lacking CTCF proteins?
A. Double helix
B. Nucleosome
C. Loop domains
D. 30-nm fiber
C. Loop domains
Long-terminal repeats are unique to which group of transposons?
A. integrase
B. non-LTR retrotransposons
C. simple transposons
D. LTR retrotransposons
D. LTR retrotransposons
During a retrotransposition event, 4 DNA copies of a retrotransposon are created. At the end of this event, how many total copies of the retrotransposon will be found in the genome?
A. 1
B. 5
C. 10
D. 8
E. 4
B. 5
The idea that the adenine and thymine bases of the DNA interact in some manner was first proposed by _______.
A. Franklin
B. Chargaff
C. Pauling
D. Watson and Crick
B. Chargaff
The term nucleic acids is used to describe RNA and DNA because
A. they are acidic molecules and have no charge at neutral pH.
B. they are acidic molecules and have a net positive charge at neutral pH.
C. they are acidic molecules and have a net negative charge at neutral pH.
C. they are acidic molecules and have a net negative charge at neutral pH.
One strand of DNA is 5′ - AGGCCTTA - 3′. What is the opposite strand?
A. 3′ - AGGCCTTA - 5′
B. 5′ - AGGCCTTA - 3′
C. 5′ - TCCGGAAT - 3′
D. 3′ - TCCGGAAT - 5′
D. 3′ - TCCGGAAT - 5′
The DNA of a bacterial cell must be compacted about _______ fold to fit within the confines of the cell.
A. 150
B. 1,000,000
C. 100
D. 1000
E. 10
D. 1000
A chromosome territory is defined as
A. a region in the nucleus that may have several chromosomes.
B. a region on a chromosome that is devoid of nucleosomes.
C. a region in the nucleus that is occupied by a single chromosome.
D. a region on a chromosome that has no protein encoding genes.
C. a region in the nucleus that is occupied by a single chromosome.
The individual who first proposed the existence of transposable elements was ____.
A. Morgan
B. Sturtevant
C. Franklin
D. McClintock
E. Watson
D. McClintock
The fact that the type R and S strains of Streptococcus pneumoniae that Griffith worked with possessed small differences in capsule structure satisfies which of the following criteria for genetic material?
A. replicatio
B. information
C. variation
D. transmission
C. variation
What is a mechanism of condensation shared by both prokaryotes and eukaryotes?
A. nucleosomes
B. loop domains
C. 30 nm fiber
D. None of these choices are correct.
B. loop domains
Where do kinetochores attach to chromosomes?
A. centromeres
B. telomeres
C. specific genes on the chromosome
D. they do not attach to DNA
A. centromeres
What is the first level of chromosome compaction among the following choices?
A. closer association of loop domains
B. 30 nm fibers
C. loop domains
D. nucleosomes
D. nucleosomes
Following transcription, the RNA has a complementary sequence to
A. the coding strand of DNA
B. termination sequences
C. the template strand of DNA
D. regulatory sequences
C. the template strand of DNA
What is the name of the site in eukaryotic DNA where general transcription factors associate?
A. terminator
B. silencer
C. enhancer
D. promoter
D. promoter
What enables the splicing of group I and II introns?
A. snRNA
B. ribozymes
C. poly-A tail
D. spliceosomes
B. ribozymes
You are working in a lab studying mRNAs from many different species. You need to distinguish between mRNAs in a mixed sample. You begin by having all of the mRNAs sequenced, including the mitochondrial mRNAs. You notice a high number of C to U conversions in the mitochondrial mRNAs from a certain portion of the sample. You conclude that this portion of the sample is from __________.
A. slime mold
B. Trypanosomes
C. Drosophila
D. Mammals
E. Plants
E. Plants
Most eukaryotic genes are colinear
A. True
B. False
C. It is unknown at this time
B. False
In prokaryotes, a holoenzyme is formed when what is added to the core enzyme?
A. b
B. b’
C. Start codons
C. σ
E. a
C. σ
Which subunit of the prokaryotic RNA polymerase carries out catalytic synthesis of RNA?
A. alpha
B. beta
C. omega
D. sigma
B. beta
How many general transcription factors are needed for eukaryotic translation?
A. 6
B. 4
C. 3
D. 5
D. 5