Term
consider the process that a cell uses to replicate its double-stranded DNA to make copies for daughter cells. which statement describes the DNA in daughter cells:
A. the double helix in one daughter cell consists of two strands that were originally in the parent cell, while the double helix in the other daughter cell consists of two newly made strands.
B. the two strands of the double helices in both daughter cells consists of segments of new and parental DNA.
C. the double helices in each daughter cell consists of one parental strand and one newly made strand. |
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Definition
| C. the double helices in each daughter cell consists of one parental strand and one newly made strand |
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Term
which term describes DNA replication?
A. conservative
B. semi conservative
C. dispersive |
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Definition
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Term
what kinds of bonds link the two strands of a double helix to each other?
A. covalent bonds
B. hydrogen bonds
C. ionic bonds |
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Definition
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Term
DNA synthesis begins at:
A. the telomers
B. the centromere
C. the replication origins
D. the CpG islands |
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Definition
| C. the replication origins |
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Term
replication origins typically consists of a small stretch of DNA that is relatively easy to open. which statement is true:
A. replication origins are rich in A and T nucleotides
B. replication origins are rich in G and C nucleotides
C. replication origins have equal numbers of A,C,G, and T nucleotides |
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Definition
| A. replication origins are rich in A and T nucleotides |
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Term
DNA synthesis proceeds:
A. in 5' to the 3' direction
B. in the 3' to the 5' direction
C. in both directions at once
D. from the centromeres to the telomeres |
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Definition
| A. in 5' to the 3' direction |
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Term
nucleotides are linked by:
A. hydrogen bonds
B. phosphodiester bonds
C. peptide bonds
D. ionic bonds |
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Definition
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Term
what provides the energy for DNA polymerization?
A. the hydrolysis of ATP (releasing P)
B. the hydrolysis of GTP (releasing P)
C. the hydrolysis of incoming nucleotides triphosphates (releasing PP) |
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Definition
| C. the hydrolysis of incoming nucleotides triphosphates (releasing PP) |
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Term
| at a replication fork, both strands of DNA are replicated in the 5'-to-3' direction: true or false |
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Definition
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Term
at a replication fork, the leading strand is synthesized:
A. continuously
B. discontinuously
C. first
D. when the lagging strand is complete |
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Definition
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Term
at a replication fork, the lagging strand is synthesized:
A. continuously
B. discontinuously
C. first
D. when the leading strand is complete |
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Definition
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Term
how often does DNA polymerase make an error during DNA replication?
A. one in every 100 nucleotide pairs
B. one in every 1000 nucleotide pairs
C. one in every 10,000,000 nucleotide pairs |
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Definition
| C. one in every 10,000,000 nucleotide pairs |
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Term
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 |
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Definition
| A. before adding the next nucleotide in the chain |
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Term
the proofreading activity of DNA polymerase occurs in which direction?
A. 5' to 3'
B. 3' to 5' |
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Definition
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Term
| during DNA replication, DNA polymerase initiates a completely new DNA strand from scratch: true or false |
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Definition
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Term
which of the following describe a primer used in DNA replication:
A. a short segment (about 10 nucleotides) of DNA
B. a short segment (about 10 nucleotides) of RNA
C. a short segment (about 10 amino acids) of a polypeptide |
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Definition
| B. a short segment (about 10 nucleotides) of RNA |
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Term
| DNA replication requires two primers: one primer for the lagging strand and one primer for the leading strand: true or false |
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Definition
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Term
what powers the action of helicase at the replication fork, where it opens up the double helix?
A. DNA nucleotide hydrolysis
B. ATP hydrolysis
C. GTP hydrolysis |
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Definition
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Term
what is the function of single-strand binding proteins in DNA replication?
A. they unwind a DNA double helix to form two separate, single strands
B. they bind to single-stranded DNA and assist in the re-formation of double-stranded DNA
C. they bind to single-stranded DNA and prevent the single-strands from re-forming base pairs |
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Definition
| C. they bind to single-stranded DNA and prevent the single-strands from re-forming base pairs |
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Term
what is the function of the sliding clamp in DNA replication?
A. it keeps DNA polymerase firmly attached to the template while it synthesizes a new strand of DNA
B. it unwinds the double helix at the replication fork to allow DNA polymerase to progress along the DNA
C. it hydrolyzes ATP to power the movement of DNA polymerase along the DNA template |
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Definition
| A. it keeps DNA polymerase firmly attached to the template while it synthesizes a new strand of DNA |
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Term
the enzyme that replicates the ends of chromosomes is called:
A. DNAse
B. telomerase
C. capping polymerase
D. DNA ligase |
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Definition
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Term
single nucleotide changes have deleterious effects on the proteins they encode.
A. always
B. sometimes
C. never |
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Definition
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Term
copying errors not caught by the replication machinery can be corrected by:
A. RNA polymerase
B. the DNA mismatch repair system
C. DNA telomerase
D. DNA maintenance methytransferase |
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Definition
| B. the DNA mismatch repair system |
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Term
DNA mismatch repair can correct what percentage of replication errors?
A. 50%
B. 80%
C. 99%
D. 100% |
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Definition
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Term
| most cancers arise from cells that have accumulated multiple mutations: true or false |
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Definition
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Term
what does depurination refer to?
A. the loss of A or G bases from DNA
B. the loss of T or G bases from DNA
C. the breaking of the DNA backbone |
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Definition
| A. the loss of A or G bases from DNA |
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Term
how does ultraviolet radiation in sunlight typically damage DNA?
A. it breaks hydrogen bonds between two strands of DNA
B. it removes nucleotides in DNA
C. it promotes covalent linkage between two adjacent pyrimidine bases. |
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Definition
| C. it promotes covalent linkage between two adjacent pyrimidine bases |
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Term
what type of enzyme removes damaged DNA from the rest of the DNA molecule?
A. polymerase
B. nuclease
C. primase
D. ligase
E. helicase |
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Definition
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Term
what type of enzyme fills the gap after damaged DNA has been removed?
A. polymerase
B. nuclease
C. primase
D. ligase
E. helicase |
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Definition
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Term
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 |
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Definition
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Term
when a cell repairs a double-strand DNA break by the process of nonhomologous end-joining:
A. the original DNA sequence at the repair site has been altered by a short deletion
B. the original DNA sequence at the repair site has been altered by a short addition
C. the original DNA sequence at the repair site has been reconstituted with 100% accuracy |
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Definition
| A. the original DNA sequence at the repair site has been altered by a short deletion |
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Term
double strand breaks can be repaired flawlessly by:
A. the DNA mismatch repair system
B. homologous recombination
C. nonhomologous end joining
D DNA maintenance methyltransferase |
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Definition
| B. homologous recombination |
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Term
in addition to its role in DNA repair, homologous recombination is also responsible for generating genetic diversity during what process?
A. mitosis
B. meiosis
C. independent assortment of chromosomes |
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Definition
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Term
| homologous recombination occurs only between DNA molecules that are identical in nucleotide sequence: true or false |
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Definition
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Term
| the homologous recombination mechanism and the proteins that carry it out are found exclusively on organisms that perform meiosis: true or false |
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Definition
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Term
mobile genetic elements, also called transposons:
A. can locate and repair damaged genes
B. provide a source of genetic variation
C. are usually lethal to the host
D. were originally synthesized by recombinant DNA technology |
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Definition
| B. provide a source of genetic variation |
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Term
| mobile genetic elements require DNA sequence similarity to enter a new location on a chromosome: true or false |
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Definition
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Term
| nearly half of the human genome is made up of copies of various mobile genetic elements: true or false |
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Definition
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Term
retrotransposons move from place to place in a genome using what type of intermediate?
A. DNA
B. RNA
C. protein |
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Definition
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Term
| the DNA in a virus typically encodes all of the enzymes necessary for the reproduction of the virus: true or false |
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Definition
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Term
viral genomes consist of what type(s) of molecules?
A. DNA
B. RNA
C. either DNA or RNA |
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Definition
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Term
retroviruses like HIV:
A. must copy their RNA genomes into DNA to replicate
B. must copy their DNA genomes into RNA to replicate
C. must copy the host's genome to replicate
D. contain no genes of their own |
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Definition
| A. must copy their RNA genomes into DNA to replicate |
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