[Yuyue Education] Nantong University Molecular Biology Reference Materials

Education
-Molecular Biology-Chapter Materials Examination Materials-Nantong University【】
Chapter 2 Thinking Questions
Chapter 2 Test
1. [Single-choice questions] The basic units of nucleic acid are
A, A. Phosphate and ribose
B, B. Nucleosides And bases
C, C. Mononucleotides
D, D. Deoxynucleosides and bases
Reference materials [ ]
2. [Single-choice question] After DNA and RNA are completely hydrolyzed, the product is characterized by
A, A. Pentose Different, partly different bases
B, B. Different pentoses, identical bases
C, C. Same pentoses, identical bases
D, D. Different pentoses, completely different bases
Reference materials [ ]
3, [single Selected topic] The main ways in which DNA exists in a helical structure in nature
A, AA-DNA
B, BB-DNA
C, CE-DNA
D, DZ-DNA
reference materials [ ]
4. [Single-choice question] The following about topoisomerase II The correct description is
A, A. It breaks the glycosidic bond in the DNA double strand
B, B. It can increase the number of DNA negative supercoils
C, C. Stabilize the topological conformation of the DNA molecule
D, D. Make the DNA molecule Becoming a positive supercoil
reference [ ]
5. [Single-choice question] The following statements about nucleic acid structure are wrong:
A, A. There is a deep groove and a shallow groove on the surface of the double helix
B, B. The double helix structure only exists in DNA molecules
C, C. The double helix structure also exists in RNA molecules
D, D. There is a base complementary relationship in the double helix structure region
Reference materials [ ]
6. [Single-choice question] DNA molecules do not include
A, A. Phosphodiester Bond
B, B. Glycosidic bond
C, C. Disulfide bond
D, D. Van der Waals force
Reference materials [ ]
7. [Single-choice question] Which is the wrong relationship between the base content of DNA molecules
A, A.A+T=C +G
B, B.A+G=C+T
C, CG=C
D, DA/T=G/C
Reference materials [ ]
8. [Single-choice question] Pentose (R), The connection relationship between base (N) and phosphate (P) is
A, AN-RP
B, BN-PR
C, CP-NR
D, DP-NP
Reference materials [ ]
9. [Single-choice question] About DNA double helix structure The description of the theory, which one is wrong
A, A. Composed of two antiparallel DNA strands
B, B. The bases have a strict pairing relationship
C, C. The base plane is perpendicular to the central axis
D, D. All secondary structures of DNA in biological cells are right - handed
helix .




D. D. 220nm
reference materials [ ]
11. [Single-choice question] DNA denaturation refers to
A, A. Polynucleotide chain depolymerization
B, B. DNA molecule changes from superhelix to double helix
C, C. Between bases Hydrogen bond breaking
D, D. Complete hydrolysis of nucleic acid molecules
Reference materials [ ]
12. [Multiple choice] The forces that promote the stability of the DNA double helix structure mainly include
A, A. The phosphodiester bond in the molecule
B, B. Alkaline Hydrogen bonds between base pairs
C, C. Stacking force between base planes
D, D. Negative repulsion between phosphates on the backbone
Reference materials [ ]
13. [Multiple choice] The following descriptions about the hybridization of nucleic acid molecules, The correct one is
A, A. Can occur between DNA and DNA strands from different sources
B, B. Can occur between DNA and RNA strands from different sources
C, C. The nature of DNA denaturation and renaturation is molecular hybridization Basic
D, D. Hybridization technology can be used to study the structure and function of nucleic acid.
References 【 】
14. [Multiple choice] The correct description of the DNA double helix structure model is
A, A. The number of molecules of adenine is equal to that of thymine The number of molecules
B, B. The number of molecules of adenine with base pairs located inside the DNA double helix is ​​equal to the number of molecules of thymine
C, C. Every 10.5 bp is coiled for one week, and the pitch is 3.4nm.
D, D. DNA double helix structure The stable vertical depends on the hydrophobic stacking force of the base plane.
Reference materials【 】
15. 【Multiple choice】Which of the following changes occurs to double-stranded DNA at the melting temperature?
A, A. The double-stranded helix is ​​completely unwound
B, B. The double-stranded helix is ​​50% unwound
C, C. Compared with room temperature, its absorbance value at 260nm increases
D, D. The hydrogen bond between base pairs Fracture
Reference materials [ ]
Chapter 3 Homework
Chapter 3 Test
1. [Single-choice question] When nucleic acid hybridizes, the probe and the gene to be tested ( ).
A, Homologous
B, Recombination
C, Amplification
D, Crossover
E, Complementary
reference Information 【 】
2. [Single-choice question] Regarding the structural characteristics of the prokaryotic genome, which of the following statements is incorrect ()
A. The genome is usually composed of only one circular double-stranded DNA molecule
B. There are multiple replication origins in the genome
C . Generally no overlapping genes
D. No introns
E. The structural gene is a single copy.
Reference materials [ ]
3. [Single-choice question] Regarding the structural characteristics of the viral genome, which of the following statements is correct ()
A. The viral genome is composed of DNA
B. The viral genome is mostly multi-copy
C. The genes of the viral genome are continuous
D. Most of the viral genome is used to encode proteins
E. No overlapping genes
Reference materials [ ]
4. [Single-choice question] The one with the smallest number of genes Biology is ()
A, Mycoplasma
B, Escherichia coli
C、酵母
D、线虫
E、人
参考资料【 】
5、【单选题】关于真核生物基因组的结构特点，下列说法错误的是（）
A、真核生物基因组的大部分为非编码序列
B、真核生物基因组存在大量的重复序列
C、真核基因的转录产物多为多顺反子
D、真核基因是断裂基因
E、真核基因组中存在大量的顺式作用元件
参考资料【 】
6、【单选题】序列长度平均约为300bp，它们与平均长度约为1000bp的单拷贝序列间隔排列，拷贝数大于10万，这种DNA序列称（）
A、小卫星DNA
B、微卫星DNA
C、反向重复序列
D、短散在重复序列
E、长散在重复片段
参考资料【 】
7、【单选题】人类基因组由3X10^9 bp组成,其所含的基因总数大约有多少个（）
A、3000万
B、300万
C、30万
D、3万左右
E、3千
参考资料【 】
8、【单选题】以遗传标志作为路标，遗传学距离为图距的基因组图称（）
A、转录图
B、物理图
C、遗传图
D、序列图
E、定位图
参考资料【 】
9. [Single-choice question] The name of the genome map with the sequence tag site as the landmark and the length of DNA in base pairs (bp), kilobase pairs (kb) or megabase pairs (Mb) as the map distance ()
A. Transcription map
B, Physical map
C, Genetic map
D, Sequence map
E, Location map
Reference materials [ ]
10, [Single-choice question] Exon representative ()
A, a DNA sequence that can be transcribed
B, a Transcription regulatory sequence
C, a gene sequence
D, a spacer sequence E between genes
, a DNA sequence that can correspond to mRNA or other functional RNA molecules
Reference materials [ ]
11. [Single-choice question] The base sequence of the human genome encoding protein The proportion is ()
A, 100%
B, 25%
C, 50%
D, 1-2%
E, 5-10%
Reference materials [ ]
12. [Single-choice question] The repetitive sequence in the human genome accounts for about ()
A, 99%
B, 90%
C, 45%
D, 25%
E, 10%
reference materials [ ]
13. [Single-choice question] The following are 5 kinds of DNA double helices composed of different sequences, which are carried out under the same conditions Thermal denaturation followed by renaturation by slow cooling. Do you think the fastest refolding sequence is ()
A, ATATATAT
B, AATATTAT
C, AAAATTTA
D. AAAATTTT
E, ATAAATTA
reference materials [ ]
14. [Single-choice question] The sequence that contributes the most to the contradiction of the C value is ()
A. Gene encoding protein
B, gene encoding tRNA
C, gene encoding rRNA
D, encoding interference Gene
E of RNA, non-coding sequences between
genes
. Fragments, then heat denatured, and finally renatured by cooling. The statement about the renaturation of the genome DNA of the two organisms is correct ()
A. The renaturation rate of a part of the monkey DNA is much faster than that of the bacterial DNA, and the other part is slower than that of the bacteria
B. The renaturation rate of the bacterial DNA is lower than that of the bacteria Monkey renaturation is slow because more bacteria are needed to produce the same amount of DNA
C. Bacterial DNA renaturation is faster than monkey DNA because the bacterial genome is much smaller and simpler than the monkey genome
D. The renaturation rate is similar, Because the molecular composition and structure of all DNA are the
same . Reference materials [ ] 17. [Single-choice question] In many different species, highly conserved sequences are generally () A, pseudogenes B, specific spacer sequences C, very important protein genes











D. An unimportant protein with
E. An Alu repeating sequence
Reference [ ]
18. [Single-choice question] What is the possible composition of the viral genome ()
A. It is composed of RNA only.
B. It is composed of DNA only.
C. RNA or DNA.
D, RNA and DNA.
Reference materials [ ]
19. [Single-choice question] A gene with 6 exons contains () intron
A, 5 intron
B, 6 intron
C , 7 introns
D, not necessarily
Reference materials [ ]
20, [Multiple choice] The following statements about hybridization of nucleic acid molecules are correct
A, A. Can occur between DNA and DNA strands from different sources
B, B. Can occur between DNA and RNA strands from different sources
C, C. The nature of DNA denaturation and renaturation is the basis of molecular hybridization
D, D. Hybridization technology can be used in the study of nucleic acid structure and function
Reference materials [ ]
21, 【Multiple choice】Which of the following changes occurs to double-stranded DNA at the melting temperature?
A, A. The double-stranded helix is ​​completely unwound
B, B. The double-stranded helix is ​​50% unwound
C, C. Compared with room temperature, its absorbance value at 260nm increases
D, D. The hydrogen bond between base pairs Fracture
Reference materials [ ]
22. [Multiple choice] Which of the following statements about renaturation of DNA is correct?
A. Refolding is carried out between two complementary strands of denatured DNA molecules
B. The larger the DNA molecule, the longer the renaturation time
C. The thermally denatured DNA needs to be cooled slowly before renaturation
D. The denaturation process can occur between the DNA and RNA strands.
Reference materials [ ]
23. [Multiple choice] complex Which of the following reactions are included in the sexual process?
A. Formation of hydrogen bonds B.
Formation of nucleoside bonds
C. Formation of stacking force between base pairs D. Formation
of covalent bonds The description of hybridization of nucleic acid molecules is correct. A. It can occur between DNA and DNA strands from different sources. B. It can occur between DNA and RNA strands from different sources. C. The nature of DNA denaturation and renaturation is molecular hybridization Basic D. Hybridization technology can be used to study the structure and function of nucleic acids. Reference materials [ ] 25. [Multiple-choice question] The genome of a virus can be A, dsDNA B, ssDNA C, dsRNA D, ssRNA Reference materials [ ] 26. [Judgement question] 】A gene is a DNA sequence that encodes a protein (enzyme) A, correct B, incorrect reference material 【 】27, [Judgment] In the entire biological world, the chemical essence of most biological genes is DNA A, correct B, incorrect reference Information 【 】28. [Judgment question] A broken gene refers to a DNA sequence that does not encode a functional product between two genes to separate them






















A. Correct
B. Incorrect
Reference materials 【 】
29. 【Judgement】Plasmids have a replication origin and can replicate independently in host cells
A. Correct
B. Incorrect
reference materials 【 】
30. 【Judgement】Eukaryotes Chromosomal DNA molecules are circular
A, correct
B, incorrect
reference materials [ ]
31, [judgment question] all prokaryotic genomes are double-stranded circular DNA molecules
A, correct
B, incorrect
reference materials [ ]
the second part of the test
1, [Single-choice question] DNA polymerase does not need A during DNA replication
, template strand that can be read from 3'-5'
B, dNTPs
C, primer
D, promoter
Reference materials [ ]
2, [Single-choice question] DNA replication In the process, the role of DNA gyrase (DNA gyrase) is
A, to catalyze the transport reaction
B, to unravel the DNA on the replication fork by breaking the hydrogen bond
C, to synthesize the replication initiation primer
D, to expand the DNA double strand before the replication fork
Reference materials [ ]
3. [Single-choice question] In the following repair process, the chain to be repaired is judged by the methylation status of the chain is
A, recombination repair
B, mismatch repair
C, shear repair
D, SOS repair
reference materials 【 】
4. [Single-choice question] Gene mutations are usually introduced in the following repair methods:
A, photoreactivation
B, recombination repair
C, shear repair
D, SOS repair
Reference materials [ ]
5. [Single-choice question] The following repairs The methods that only work when pyrimidine dimers are produced are
A, shearing repair
B, photoreactivation
C, SOS repair
D, recombination repair
Reference materials [ ]
6, [Single-choice question] Silent mutation of the gene will lead to
A . The protein encoded by the gene will not be expressed
B. The nucleotide sequence of the mRNA encoded by the gene will not change
C. The amino acid sequence of the protein encoded by the gene will not change
D. A certain amino acid in the protein encoded by the gene will be changed Another amino acid substitution, but it will not lead to a change in protein function.
Reference materials [ ]
7. [Single-choice question] Which of the following statements about DNA and RNA polymerase is correct ( )
A. Nucleosides for RNA polymerase Diphosphates instead of nucleoside triphosphates to synthesize polynucleotide chains
B. RNA polymerase needs primers and adds nucleotides
C to the 5' end of growing polynucleotide chains. DNA polymerase can synthesize nucleotide chains All RNA
and DNA polymerases can only add nucleotides at the 3' end of the growing polynucleotide chain.
Reference materials [ ]
8. [Single-choice question] About DNA replication and transcription , the following statements are wrong:
A, all use DNA as a template
B, the product of replication is double-stranded DNA, and the product of transcription is single-stranded RNA
C. Comply with AT pairing and GC pairing
D. The products are all polynucleotide chains
Reference materials [ ]
9. [Single-choice question] Mismatch repair is based on the recognition of mismatches generated during replication. The following statement is correct:
A. UvrABC system recognizes and uses DNA polymerase I to promote the introduction of correct nucleotides so that the mismatch is repaired.
B. If the recognition occurs before the re-methylated hemimethylated DNA, then Repair may be biased towards wild-type sequence
C. Mismatches are generally repaired by single-strand exchanges. This depends on the ability of RecA protein to restore the normal copy sequence
D. Mismatch repair is completed by the repair function inhibited by LexA protein under normal circumstances (SOS response)
Reference materials [ ]
10. [Single-choice question] DNA damage in cells Among the responses made, which method may lead to a high mutation rate
A, photoreactivation repair
B, base excision repair
C, recombination repair
D, transfer loss synthesis
Reference materials [ ]
11, [single-choice question] in most In DNA repair, a four-step sequence reaction is involved. The order of the four-step sequence reaction is
A, recognition, excision, resynthesis, religation
B, religation, resynthesis, excision, recognition
C, excision, resynthesis, religation . Recognition
D. Recognition, resynthesis, religation, excision
Reference materials [ ]
12. [Single-choice question] In the process of photoreactivation and repair, which of the following enzymes binds to pyrimidine dimers
A, photolyase
B, extranucleic acid Dicer
C, endonuclease
D, ligase
Reference materials【 】
13. [Single-choice question] The enzymes that are not needed in base excision repair are
A, DNA polymerase
B, phosphodiesterase
C, exonuclease
D, and ligase
Reference materials [ ]
14. [Single-choice question] Contains The DNA of the pyrimidine dimer can still be used as a template during the replication process. When the replication machinery encounters a damaged site, the synthesis of the DNA sub-strand will be completed by which of the following enzymes A, DNA polymerase I B,
DNA
polymerase III
C, RecA
D. Loss Synthetase
References 【 】
15. [Single-choice question] Coli's UvrAB complex can recognize
A, the gap between Okazaki fragments
B, normal DNA
C, hemimethylated GATC
D, twisted DNA double Helical structure
Reference materials [ ]
16. [Single-choice question] Regarding DNA repair, which of the following descriptions is incorrect
A. UV irradiation can cause cross-linking between adjacent thymines
B. DNA polymerase III participates in the repair of nuclei Single-strand gap in the course of nucleotide excision repair system
C. DNA ligase D is required in the process of DNA repair
. Mammalian cells can use different glycosylases to remove specific damaged bases.
Reference materials [ ]
17, [ Multiple choice question] Which type of mutation is the most irreversible?
A. Nucleotide deletion or insertion
B. Hydrolytic deamination
C. Octaoxoguanine
D. Pyrimidine dimer
Reference materials 【 】
18. [Single-choice question] Insertion or deletion of base pairs will cause frameshift mutations. Which of the following compounds is most likely to cause such mutations ( ) A, acridine
derivatives
B, 5-bromouracil
C, azathioprine
D , Ethylethanesulfonic acid
Reference materials [ ]
19. [Single-choice question] When cultivating Escherichia coli, spontaneous point mutations are mostly caused by ():
A. Tautomeric shift of hydrogen atoms
B. DNA sugar- Breakage of the phosphate backbone
C. Insertion of a base pair
D. Cross-linking between strands
Reference materials [ ]
20. [Single-choice question] The most common form of DNA damage caused by ultraviolet radiation is the formation of thymine dimers. Which of the following statements about this change in the molecular structure of DNA is correct?
A. It is the covalent link between thymine between two complementary nucleotide chains.
B. It can be repaired by related enzyme systems including nucleotide excision repair system.
C. It is catalyzed by thymine dimer enzyme. D.
Will not affect DNA replication
Reference materials 【 】
21. [Single-choice question] The substitution of a single base is a form of DNA damage, they ():
A. Affect transcription but not replication
B. Affect DNA sequence but not Does not affect the secondary structure of DNA
C, can cause changes in the DNA double helix structure but does not affect the replication cycle D, can be caused by UV irradiation (such as pyrimidine dimer) or the formation of
addition compounds (such as alkylation)
【 】
22. [Single-choice question] The main damage to DNA molecules caused by ultraviolet radiation is ():
A. Formation of covalently linked pyrimidine dimers
B. Base replacement
C. Phosphate bond breaking
D. Base loss
Reference materials [ ]
23. [Single-choice question] Which of the following belongs to DNA spontaneous damage ():
A. Base mismatch during DNA replication
B. , Thymine dimer formation
C, cytosine deoxygenation
D, DNA cross-linking
Reference materials 【 】
24. 【Single-choice question】Knockout of kinase A in mice can lead to mouse embryonic death, and the kinase A gene When the following mutations occur in the coding sequence, the ones most likely to cause mouse embryo death are ():
A. Adenine replaces cytosine
B. Cytosine replaces guanine
C. Deletion of three nucleotides
D. Insertion of a nucleotide
reference Information [ ]
25. [Single-choice question] Sickle cell anemia is a clinical manifestation of abnormal hemoglobin homozygous gene. The β-strand variation is caused by which of the following mutations ():
A. Chromosome arm exchange
B. Single nucleotide insertion
C. Chromosome nondisjunction
D. Base substitution
Reference materials [ ]
26, [Single-choice question] E . MutH in coli can recognize ():
A, twisted DNA double strands
B, hemimethylated GATC
C, intercalator insertion site
D, gap between Okazaki fragments
Reference materials 【 】
27, 【single choice Question] A male suffers from Fragile X Syndrome (CGG) n, the cause of which is that n changed from 60 to 300. May I ask what kind of phenomenon happened:
A. Synonymous mutation
B. Missense mutation
C. Frameshift mutation
D. Dynamic mutation
Reference materials [ ]
28. [Single-choice question] The frameshift mutation may be due to base pair ():
A. Conversion
B. Transversion
C. Hydrolysis
D 、Insert
reference materials【 】
29. 【Single-choice question】After Dolly the sheep came out, many people suspected that Dolly might not come from somatic cells of adult sheep, but from embryonic cells contaminated in experiments. Then the evidence supporting that Dolly comes from somatic cells instead of embryonic cells should be
A, Dolly’s DNA fingerprint
B, Dolly’s DNA melting temperature
C, Dolly’s telomere length
D, Dolly’s biological clock
Reference materials【 】
30、【 Multiple choice questions] The "clock" that controls the number of cell divisions is a special structure (telomere) located at both ends of chromosomes, which gets shorter as cells divide. In cancer cells, there are enzymes that lengthen telomeres of chromosomes, as well as in germ cells of normal people. Based on this, you think that the reason why somatic cells cannot divide indefinitely is
A. lack of amino acid for synthesizing telomerase
B. lack of gene controlling telomerase synthesis
C. mutation of gene controlling telomerase synthesis
D. expression of telomerase and The activity is strictly regulated
Reference materials [ ]
31. [Single-choice question] When a cell loses telomerase activity, which of the following situations will not occur
A. With each division of the cell, the telomere is gradually shortened
B. The division is 30-50 After three times, there are signs of aging and death
C. The immune system gradually loses some defense mechanisms
D. A large number of somatic cells have the ability to divide indefinitely
Reference materials [ ]
32. [Single-choice question] The following descriptions of telomerase are correct:
A. It exists in a large number in eukaryotes.
B. They all have chemical factors of C, H, O, N, and P.
C. It passes through RNA The occurrence of catalytic reaction belongs to ribozyme
D, which can carry genetic information.
Reference materials [ ]
33. [Single-choice question] In the following discussion about telomeres, the correct answer is
A. Telomeres are nucleosomes at the end of chromosomes in eukaryotic cells The special structure of the composition
B. Telomeres play a role in maintaining the stability of DNA secondary structure
C. Telomerase has both template and reverse transcriptase functions
D. Aging at the cellular level and abnormal extension of telomeres
[ 】
34. [Single-choice question] Telomerase is a kind of
A, DNA-dependent DNA polymerase
B, DNA-dependent RNA polymerase
C, RNA-dependent DNA polymerase
D, RNA-dependent RNA polymerase
Reference materials [ ]
35. [Single-choice question] The proteins that recognize the DNA replication initiation region of Escherichia coli are
A, DnaA
B, DnaB
C, DnaC
D, ORC
Reference materials [ ]
36. [Single-choice question] DNA replication needs: ( 1) DNA polymerase III, (2) helicase, (3) DNA polymerase I, (4) DNA-guided RNA polymerase, (5) DNA ligase participates, and the sequence of action is A,
2,3 ,4,1,5
B, 4,2,1,5,3
C, 4,2,1,3,5
D, 2,4,1,3,5
reference materials 【 】
37, [single-choice question] Catalyze the formation of phosphate diphosphate between adjacent 5' phosphate groups and 3' hydroxyl groups in DNA The enzyme of the ester bond is
A, methyltransferase
B, ligase
C, primerase
D, DNA Pol I
Reference materials [ ]
38, [Single-choice question] When DNA molecules are replicated, the description of the role of helicase is wrong
A. Under the action of helicase, the hydrogen bond between base pairs is opened.
B. It needs to consume ATP to provide energy.
C. The helicase binds to the DNA double helix.
D. The activity of helicase is activated by the DNA replication complex deoxyribose Chemical bond with phosphoric acid
Reference materials 【 】
39. [Single-choice question] The enzyme that releases the positive supercoiled structure of DNA is
A, primase
B, gyrase
C, helicase
D, telomerase
Reference materials 【 ]
40. [Single-choice question] In prokaryotes, which of the following enzymes can play a role in the process of removing RNA primers and adding deoxyribonucleotides?
A. A. DNA polymerase III
B. B. DNA polymerase II
C. C. DNA polymerase I
D. D. Exonuclease MFI
reference materials [ ]
41. [Single-choice question] The fidelity effect of DNA replication Does not include
A, A. Eukaryotic DNA-polδ instant proof reading function
B, B. Immediate proofreading function of primerase
C, C. DNA-pol base selection function
D, D. Strict base pairing rules
Reference materials [ ]
42, [Single-choice question] About prokaryotic DNA polymerization The description of enzyme III is correct
A, A. has 3'→5' exonuclease activity
B, B. has 5'→3' exonuclease activity
C, C. has 3'→5' polymerase activity
D , D. The substrate is NTP
reference materials [ ]
43, [Single-choice question] In prokaryotes, filling the gap generated by DNA replication or repair mainly depends on
A, A. DNA polymerase I
B, B. DNA polymerase II
C, C. DNA polymerase α
D, D. DNA polymerase β
reference materials [ ]
44, [Single-choice question] The DNA polymerase responsible for chromosomal DNA replication in Escherichia coli is
A, A. DNA polymerase I
B, B. DNA polymerase II and III
C, C. DNA polymerase V D, D. Reference materials of DNA
polymerase I and III [ ] 45. [Single-choice question] A, A. Sanger Method B, B. Density gradient centrifugation C, C. Alpha complementation D, D. Dot hybridization Reference materials 【 】46. 【Single-choice question】Which of the following chemical substances induce mutations by alkylating specific bases? () A, 5-bromouracil









B. Hydroxylamine
C. Methyl methanesulfonate
D. Nitrous oxide
Reference materials [ ]
47. [Single-choice question] GC base pair mutation to AT base pair, this mutation belongs to ()
A, transversion
B , conversion
C, transposition
D, translocation
Reference materials 【 】
48. 【Single-choice question】DNA polymerase does not need A during DNA replication
A, template strand that can be read from 3'-5'
B, dNTPs
C, primer
D , Promoter
reference materials [ ]
49, [Single-choice question] The role of DNA gyrase (DNA gyrase) in the process of DNA replication is
A, to catalyze the translocation reaction
B, to unwind the DNA on the replication fork by breaking hydrogen bonds
C, Synthetic replication initiation primer
D. It is the unfolding of DNA double strands before the replication fork.
Reference materials [ ]
50. [Single-choice question] In the following repair process, the strand to be repaired is judged by the methylation status of the strand.
A. Recombination repair
B. Mismatch repair
C. Cutting repair
D. SOS repair
References [ ]
51. [Single-choice question] Gene mutations are usually introduced in the following repair methods
A. Photoreactivation
B. Recombination repair
C. Cutting Repair
D, SOS repair
Reference materials【 】
52. [Single-choice question] The following repair methods only work when pyrimidine dimers are produced:
A, cutting repair
B, photoreactivation
C, SOS repair
D, recombination repair
Reference materials [ ]
53, [single choice Question] A silent mutation of a gene will cause
A. The protein encoded by the gene will not be expressed
B. The nucleotide sequence of the mRNA encoded by the gene will not change
C. The amino acid sequence of the protein encoded by the gene will not change
D. The gene A certain amino acid in the encoded protein will be replaced by another amino acid, but it will not lead to a change in the function of the protein.
Reference materials [ ]
54. [Single-choice question] Which of the following statements about DNA and RNA polymerase is correct ( )
A. RNA polymerase uses nucleoside diphosphates instead of nucleoside triphosphates to synthesize polynucleotide chains
B. RNA polymerase needs primers and adds nucleotides
C to the 5' end of the growing polynucleotide chains. DNA polymerase can add nucleotide
D at both ends of the nucleotide chain , and all RNA and DNA polymerases can only add nucleotides at the 3' end of the growing polynucleotide chain
Reference materials 【 】
55, 【 Multiple-choice question] Regarding DNA replication and transcription, the following statements are wrong:
A, all use DNA as a template
B, the product of replication is double-stranded DNA, and the product of transcription is single-stranded RNA
C, follow AT pairing, GC pairing
D, the product Both are polynucleotide chains
Reference materials 【 】
56. 【Single-choice question】Mismatch repair is based on the recognition of mismatches generated during replication. Which of the following statements is correct
A. The UvrABC system recognizes and relies on DNA polymerase I to promote the introduction of the correct nucleotide so that the mismatch is repaired.
B. If the recognition occurs before the re-methylated hemi-methylated DNA, the repair may be biased towards the wild type Sequence
C. Mismatches are generally repaired by single-strand exchanges. This depends on the ability of RecA protein to restore the normal copy sequence
D. Mismatch repair is completed by the repair function inhibited by LexA protein under normal circumstances (SOS response)
Reference materials [ ]
57. [Single-choice question] DNA damage in cells Among the responses made, which method may lead to a high mutation rate
A, photoreactivation repair
B, base excision repair
C, recombination repair
D, transfer loss synthesis
Reference materials [ ]
58, [single-choice question] in most In DNA repair, a four-step sequence reaction is involved. The order of the four-step sequence reaction is
A, recognition, excision, resynthesis, religation
B, religation, resynthesis, excision, recognition
C, excision, resynthesis, religation . Recognition
D. Recognition, resynthesis, reconnection, excision
Reference materials [ ]
59. [Single-choice question] If the recovery rate of a mutation is abnormally high, then the cause of this mutation is probably ().
A. Deletion of one base pair
B. Formation of pyrimidine dimer
C. Transposon
D. Defect of self-proofreading and repairing system
E. Insertion of one base pair
Reference materials [ ]
60. [Single-choice question] RecA protein is not The activity is ()
A. Participating in homologous recombination
B. Having endonuclease activity
C. Participate in the SOS reaction
D. Can bind single-stranded DNA
Reference materials 【 】
61. 【Single-choice question】The DNA fragments that need to be ligated by DNA ligase have ()
A, 5&
B, 39; -OH and 3&
C, 39 -P
D, 3&
E, 39; -OH and 3&
F, 39; -OH
G, 3&
H, 39; -OH and 5&
I, 39; -OH
J, 5&
K, 39; -P and 5&
L, 39;-P
M, 3&
N, 39;-OH and 5&
O, 39;-P
Reference materials [ ]
62. [Single-choice question] The patient with hereditary nonpolyposis rectal cancer contains microsatellite instability gene, and the patient's DNA contains abnormal small loops that are not paired in many regions. The mutations that lead to the above results occurred in ()
A, mismatch repair system
B, double-strand break repair system
C, base excision repair system
D, direct repair system
E, nucleotide excision repair system
Reference materials [ ]
63, [single Topic selection] The DnaB protein of Escherichia coli is a kind of ()
A, DNA polymerase
B, DNA gyrase
C, DNA helicase
D, DNA primase
E, DNA ligase
Reference materials【 】
64. [Single-choice question] The best materials for isolating and purifying telomerase are ()
A, bacteria
B, virus
C, kidney cells
D, Tetrahymena
E, brain cells
Reference materials [ ]
65, [Single-choice question] Recombination includes breaks and recombinations from ()
A, homologous non-sister chromatid
B, homologous sister chromatid
C, non-homologous non-sister chromatid
D, non-homologous sister Chromatid
E, none of the above
References 【 】
66, [Single-choice question] What is very important in the process of generating genetic diversity ()
A, Translation
B, Transcription
C, Recombination
D, Transformation
E, None of the above
Reference materials [ ]
67. [Single-choice question] The role of RNA primers during replication is ()
A. Activate DNA polymerase III
B. Provide 5&
C, 39;-P to synthesize DNA strands
D. Provide 3&
E, 39;- OH synthesizes DNA strand
F, provides 5&
G, 39;-P to synthesize RNA strand
H, and unwinds DNA double strands
. Covalently linked pyrimidine dimers B, base substitution C, cleavage of phosphate bonds




D. Base loss
Reference materials【 】
69. 【Single-choice question】Which of the following belongs to DNA spontaneous damage ():
A. Base mismatch during DNA replication
B. Thymine dimer formation
C. Cytosine Deoxy
D, DNA cross-linking
reference materials [ ]
70, [Single-choice question] Knockout of kinase A in mice can lead to embryonic death in mice, and the following mutations in the coding sequence of kinase A gene are most likely to cause small The mouse embryo died ():
A, adenine replaced cytosine
B, cytosine replaced guanine
C, three nucleotides were missing
D, one nucleotide was inserted
Reference materials [ ]
71, [Single-choice question] Sickle Erythrocytic anemia is a clinical manifestation of a homozygous gene for abnormal hemoglobin. The β-strand variation is caused by which of the following mutations ():
A. Chromosome arm exchange
B. Single nucleotide insertion
C. Chromosome nondisjunction
D. Base substitution
Reference materials [ ]
72, [Single-choice question] E . MutH in coli can recognize ( ):
A, twisted DNA double strand
B, hemimethylated GATC
C, intercalator insertion site
D, gap between Okazaki fragments
Reference materials 【 】
73, 【single choice Question] A male suffers from Fragile X Syndrome (CGG) n, the cause of which is that n changed from 60 to 300. May I ask what kind of phenomenon happened:
A, synonymous mutation
B, missense mutation
C, frameshift mutation
D. Dynamic mutation
Reference materials [ ]
74. [Single-choice question] The frameshift mutation may be due to base pair ():
A. Conversion
B. Transversion
C. Hydrolysis
D. Insertion
Reference materials [ ]
75. [Single-choice question] Topic selection] After Dolly the sheep came out, many people suspected that Dolly might not come from somatic cells of adult sheep, but from embryonic cells contaminated in experiments. Then the evidence supporting that Dolly comes from somatic cells instead of embryonic cells should be
A, Dolly’s DNA fingerprint
B, Dolly’s DNA melting temperature
C, Dolly’s telomere length
D, Dolly’s biological clock
Reference materials 【 】
76, 【 Multiple choice questions] The "clock" that controls the number of cell divisions is a special structure (telomere) located at both ends of chromosomes, which gets shorter as cells divide. In cancer cells, there are enzymes that lengthen telomeres of chromosomes, as well as in germ cells of normal people. Based on this, you think that the reason why somatic cells cannot divide indefinitely is
A. lack of amino acid for synthesizing telomerase
B. lack of gene controlling telomerase synthesis
C. mutation of gene controlling telomerase synthesis
D. expression of telomerase and Activity is strictly regulated.
Reference materials [ ]
77. [Single-choice question] When a cell loses telomerase activity, which of the following situations will not occur
A. With each division of the cell, the telomere is gradually shortened
B. The division is 30-50 After three times, there are signs of aging and death
C. The immune system gradually loses some defense mechanisms
D. A large number of somatic cells have the ability to divide indefinitely
Reference materials [ ]
78. [Single-choice question] Which of the following descriptions of telomerase is correct
A. Exist in a large number of eukaryotes
B. All have C, H, O, N, P chemical factors
C. It is a ribozyme that occurs through RNA-catalyzed reactions
D. Can carry genetic information
Reference materials [ ]
79, [Single-choice question] In the following discussion about telomeres, the correct answer is
A. Telomeres are special structures composed of nucleosomes at the end of chromosomes in eukaryotic cells.
B. Telomeres play a role in maintaining the stability of DNA secondary structures.
C. Telomeres Granzyme has the function of both template and reverse transcriptase
D. Aging at the cellular level is related to abnormal extension of telomeres
Reference materials [ ]
80. [Single-choice question] Telomerase is a kind of
A. DNA-dependent DNA Polymerase
B, DNA-dependent RNA polymerase
C, RNA-dependent DNA polymerase
D, RNA-dependent RNA polymerase
Reference materials [ ]
81, [Single-choice question] The protein that recognizes the DNA replication initiation region of Escherichia coli Yes
A, DnaA
B, DnaB
C, DnaC
D, ORC
reference materials [ ]
82, [Single-choice question] DNA replication requires: (1) DNA polymerase III, (2) helicase, (3) DNA polymerase I , (4) DNA-guided RNA polymerase, (5) DNA ligase participates, the sequence of action is
A, 2, 3, 4, 1, 5
B, 4, 2, 1, 5, 3
C, 4, 2,1,3,5
D, 2,4,1,3,5
reference materials【 】
83. [Single-choice question] The enzymes that catalyze the formation of phosphodiester bonds between adjacent 5' phosphate groups and 3' hydroxyl groups in DNA are
A, methyltransferase
B, ligase
C, primerase
D, and DNA Pol I
reference materials 【 】
84. [Single-choice question] When DNA molecules are replicated, the wrong description of the role of helicase is
A. Under the action of helicase, the hydrogen bonds between base pairs are opened.
B. ATP needs to be consumed to provide energy
. C. The solution Gyrase binds to the DNA double helix
D. The activity of the helicase is activated by the DNA replication complex. The chemical bond between deoxyribose and phosphate Reference materials
[ ]
85. [Single-choice question] The enzyme that releases the positive supercoiled structure of DNA Yes
A. Initiase
B. Gyrase
C. Helicase
D. Telomerase
Reference materials [ ]
86. [Single-choice question] In prokaryotes, which of the following enzymes removes RNA primers and adds deoxyribose nucleus Can glycosides play a role in the process?
A, A. DNA polymerase III
B, B. DNA polymerase II
C, C. DNA polymerase I
D, D. Exonuclease MFI
reference materials [ ]
87, [Single-choice question] The fidelity effect of DNA replication Excluding
A, A. Eukaryotic DNA-pol δ instant proofreading function
B, B. Instant proofreading function of primase
C, C. DNA-pol’s base selection function
D, D. Strict base pairing rules
Reference materials [ ]
88. [Single-choice question] Regarding the description of prokaryotic DNA polymerase III, the correct ones are
A, A. have 3'→5' exonuclease activity
B, B. have 5'→3' exonuclease Enzyme activity
C, C. Has 3'→5' polymerase activity
D, D. The substrate is NTP
Reference materials [ ]
89, [Single-choice question] In prokaryotes, filling the gap generated by DNA replication or repair is mainly Rely on
A, A. DNA polymerase I
B, B. DNA polymerase II
C, C. DNA polymerase α
D, D. DNA polymerase β
reference materials [ ]
90, [Single-choice question] responsible for chromosomal DNA in Escherichia coli The copied DNA polymerase is
A, A. DNA polymerase I
B, B. DNA polymerase II and III
C, C. DNA polymerase V
D, D. DNA polymerase I and III
reference materials [ ]
91, [single Topic selection] The technology to confirm semi-conservative DNA replication is
A, A. Sanger method
B, B. Density gradient centrifugation
C, C. α complementation
D, D. Dot hybridization
Reference materials [ ]
92, [Single-choice question] Which of the following Chemicals induce mutations by alkylating specific bases? ()
A, 5-bromouracil
B, hydroxylamine
C, methyl methanesulfonate
D, nitrous oxide
Reference materials【 】
93. [Single-choice question] GC base pair is mutated into AT base pair. This mutation belongs to ()
A, transversion
B, conversion
C, transposition
D, translocation
Reference materials [ ]
94. [Single-choice question] Which of the following is an example of a nonsense mutation? ()
A, ACG → ACC
B, AUG → UUG
C, UAC → UAG
D, AAA → UUU
Reference materials [ ]
95, [Single-choice question] Suppressor mutations of nonsense mutations usually occur on the DNA encoding ( )
A, Reference materials for mRNA
B, tRNA
C, rRNA
D, and microRNA [ ] 96. [Single-choice question] How many replication forks can be separated from one replication origin? ( ) A, 1 B, 2 C, 3 D, 4 E, more than 4 references [ ] 97, [Single-choice question] The correction activity of DNA polymerase excises the wrong nucleotide from the ___ of the DNA chain ( ) A, 3& B, 39; Terminal C, 5& D, 39; Terminal E, 3& F, 39; and 5& G, 39; Terminal H, middle Reference [ ]


















98. [Single-choice question] Nitrous acid can induce the () reaction of bases in DNA molecules
A. Pyrimidine dimer;
B. Deamination;
C. Alkylation;
D. Hydroxylation
Reference materials 【 】
99. 【 Multiple-choice question] By what mechanism can ultraviolet light usually cause mutations ()
A. DNA strand breaks
B. Light-induced conversion of thymine to alkylated guanine
C. Inversion of DNA fragments
D. Induction of thymine dimers E. Deletion
of DNA fragments
Reference materials [ ]
100. [Single-choice question] The length of short repeat sequences appearing on microsatellite DNA sequences is often changed due to insertion or deletion. The fundamental reason is () A. DNA is
affected The role of alkylating reagents, methylation modification
B, UV radiation
C, DNA error-prone cross-lesion synthesis
D, sequence slippage in DNA replication
E, DNA replication is affected by intercalation reagents
Reference materials 【 】
101、 [Single-choice question] The DNA polymerases involved in the repair of E. coli SOS are ()
A, DNA polymerase Ⅰ
B, DNA polymerase Ⅱ
C, DNA polymerase Ⅲ
D, DNA polymerase Ⅳ
E, DNA polymerase ⅤReference
materials【 ]
102. [Single-choice question] How to prove that the initial cells of the cloned sheep Dolly are somatic cells rather than contaminated embryonic cells? ()
A. Dolly's DNA fingerprint
B. Dolly's DNA Tm
C. Dolly's telomere length
D. Dolly's biological clock
E. Dolly's C value
Reference materials [ ]
103. [Single-choice question] The repair system that does not require DNA polymerase is ()
A. Pyrimidine dimer Photoreactivation of
B, Error-prone repair
C, Mismatch repair
D, BER
E, NER
references 【 】
104, 【Single-choice question】Some colorectal cancers have a genetic predisposition, which is related to a DNA mismatch repair protein Related to recessive genes. However, heterozygous individuals are at increased risk for this type of rectal cancer with age. This may be because of ().
A. The bad copy of the gene is somatically mutated
B. The good copy of the gene is mutated in the germ cells
C. Mutations cause somatic accumulation of two bad copies of the gene over time
D. Eating high-fat and high-salt food E, other genes such as a tumor suppressor
gene have
mutation
Probably().
A. Deletion of one base pair
B. Formation of pyrimidine dimer
C. Transposon
D. Defect of self-proofreading and repairing system
E. Insertion of one base pair
Reference materials [ ]
106, [Single-choice question] RecA protein is not The activity is ()
A. Participating in homologous recombination
B. Having endonuclease activity
C. Participating in SOS reaction
D. Reference materials that can bind single-stranded DNA
[ ]
107. [Single-choice question] The protein that recognizes Holliday junctions in E. coli homologous recombination is ( )
A, RecA
B, RuvA
C, RuvB
D, RuvC
E, Rec BCD
reference Information [ ]
108. [Single-choice question] The DNA fragments to be ligated by DNA ligase have ()
A, 5&
B, 39;-OH and 3&
C, 39;-PD
, 3&
E, 39;-OH and 3&
F, 39; -OH
G, 3&
H, 39; -OH and 5&
I, 39; -OH
J, 5&
K, 39; -P and 5& L
, 39; -P
M, 3&
N, 39; -OH and 5&
O, 39;-P
reference materials [ ]
109, [Single-choice question] The patient with hereditary nonpolyposis rectal cancer contains microsatellite instability gene, and the patient's DNA contains abnormal small circles without pairing in many regions. The mutations leading to the above results occurred in ()
A, mismatch repair system
B, double-strand break repair system
C, base excision repair system
D, direct repair system
E, nucleotide excision repair system
Reference materials 【 】
110. [Single-choice question] The DnaB protein of Escherichia coli is a kind of ()
A, DNA polymerase
B, DNA gyrase
C, DNA helicase
D, DNA primase
E, DNA ligase
Reference materials [ ]
111, [ Multiple-choice question] The best materials for separating and purifying telomerase are ()
A, bacteria
B, virus
C, kidney cells
D, Tetrahymena
E, brain cells
Reference materials [ ]
112, [Single-choice question] Recombination includes sources from Break and recombination between ()
A, homologous non-sister chromatid
B, homologous sister chromatid
C, non-homologous non-sister chromatid
D, non-homologous sister chromatid
E. None of the above are
reference materials【 】
113. [Single-choice question] What is very important in the process of generating genetic diversity ()
A. Translation
B. Transcription
C. Recombination
D. Transformation
E. None of the above are
reference materials【 】
114. [Single-choice question] The role of RNA primers during replication is ()
A. Activate DNA polymerase III
B. Provide 5&
C, 39;-P to synthesize DNA strands
D. Provide 3&
E, 39;-OH to synthesize DNA Chain
F, offer 5&
G, 39;-P synthesize RNA strand
H, untangle DNA double strand
Reference materials [ ]
115, [Single-choice question] The main enzymes involved in the synthesis of DNA leading strand in eukaryotic nuclei are ()
A, DNA polymerase α
B, DNA polymerase β
C, DNA polymerase γ
D, DNA polymerase δ
E, DNA polymerase ξ
reference materials [ ]
116, [Single-choice question] Which of the following enzymes is not required for DNA replication ()
A, DNA Guided DNA polymerase
B, ligase
C, primerase
D, RNA-guided DNA polymerase
E, helicase (Helicase), topoisomerase (topoisomerase)
reference materials [ ]
117, [multiple choice questions] the following bases The change that belongs to the transversion is ():
A, A → G
B, T → G
C, A → T
D, C → G
Reference materials [ ]
118, [multiple choice] mutations that affect the amino acid sequence of the polypeptide chain Including ():
A. Deletion
B. Insertion
C. Nonsense mutation
D. Missense mutation
Reference materials [ ]
119. [Multiple choice] Which of the following DNA damages can be corrected by the nucleotide excision repair system
A. DNA double strands Breakage
B, base insertion
C, base alkylation
D. Formation of thymine dimer
Reference materials [ ]
120. [Multiple choice] is the common feature of all (prokaryotes, eukaryotes and viruses) replication origin sites.
A. The initiation site is a unique DNA segment that includes multiple short repeats
B. The initiation site is a palindromic sequence that forms a stable secondary structure
C. Multimeric DNA-binding proteins specifically recognize these short repeats
D. The start site is flanked by AT-rich, easy-to-untwist DNA sequences.
Reference materials [ ]
121. [Multiple-choice questions] The statement about DNA replication is correct.
A. It requires the participation of 4 dNMPs
. B. Requires the role of DNA ligase
C. Involves the formation of RNA primers D. Requires DNA
polymerase . Continuous replication is carried out B. The synthesis of the lagging strand is asymmetric replication C. The synthesis of the lagging strand is in the form of Okazaki fragments D. The synthesis of the lagging strand requires multiple DNA polymerases . Question] Which of the following statements about Escherichia coli topoisomerase is correct: A, catalyze the connection of the two segments of the gap in the DNA double helix structure B, help eliminate the supercoil of DNA molecules before the replication fork C, by breaking hydrogen bonds and base stacking function, improve the elongation of DNA polymerase D, break the phosphate bond to make the two progeny DNA strands topologically separated Reference materials 【 】













124. 【Multiple choice】Which of the following statements about DNA replication in Escherichia coli is correct
A. One strand in the double helix undergoes discontinuous synthesis
B. Okazaki fragments are produced
C. RNA primers are required
D. Single-strand binding proteins can prevent replication During the unwinding of the helix
Reference materials 【 】
125. 【Multiple choice】The DNA polymerase core enzyme does not have which of the following functions
A. Synthesize DNA in the 5'→3' direction B. Synthesize DNA
in the 3'→5' direction C.
Proofreading function
D. Linking Okazaki fragments
Reference materials [ ]
126. [Judgment question] The cytosine in the nucleotide is easily hydrolyzed and deaminated, so the genome contains a lot of uracil nucleotides
A, correct
B, wrong
reference Information [ ]
127. [True or False Question] Hydrolytic deamination of 5-methylcytosine is a hotspot of mutation in the genome
A, correct
B, wrong
Reference materials [ ]
128. [True or False Question] Oxidative damage of bases in DNA can be spontaneous Occurrence
A, correct
B, error
Reference materials [ ]
129, [True question] In the process of repairing the apurinization site and base excision repair in the genome, glycosidase is required to catalyze the connection of the correct base to the base deletion site On the point of pentose sugar
A, correct
B, wrong
Reference materials [ ]
130, [Judgment question] Nitrite is a common food additive, and the nitrosamine itself and the nitrosamine produced by the reaction with amino acid during the heating process are DNA inducers variable agent
A. Correct
B. Incorrect
Reference materials [ ]
131. [Judgment question] Prokaryotic cells are susceptible to DNA damage caused by the influence of the external environment, and their transfection synthetase is usually actively expressed by the transcriptional activation of RecA protein A. Correct
B.
Incorrect
Reference materials [ ]
132, [Judgment Question] The apurinic site on the DNA chain can be repaired by specific glycosidases by adding corresponding bases in the way of base pairing with the complementary chain A, correct
B
, wrong
reference materials [ ]
133, [ True or False] The nucleotide excision repair system is the same as the mismatch repair system in replication, both recognize the distortion of the DNA double helix skeleton to find the damage site, so the damage site can be scanned through the same protein complex
A , Correct
B, Incorrect
reference materials [ ]
134, [Judgment question] The single-strand gap generated after the replication mismatch site in Escherichia coli is hydrolyzed is filled by DNA polymerase I
A, correct
B, incorrect
reference materials [ ]
135, [Judgment question] MutL uses hydrolyzed ATP to provide energy to hydrolyze a sequence containing a mismatch site in the
progeny
chain . Utilize the gap between Okazaki fragments on the lagging strand to hydrolyze the mismatch site of the nascent strand A, correct B, incorrect reference materials [ ] 137, [Judgment] MutS in the mismatch repair system detects the sequence identifier of the progeny strand mismatch site






A. Correct
B. Incorrect
Reference [ ]
138. [True or False] The hemimethylation status of the GATC sequence in the DNA sequence near OriC in E.coli is closely related to the initiation of replication.
A. Correct
B. Incorrect
Reference materials 【 】
139. 【Judgement】DnaA protein will further recruit the helicase DnaB after binding to the 9-nucleotide repeat sequence in oriC to interact with the 13-nucleotide repeat sequence and unwind it
A. Correct
B. Incorrect
reference materials [ ]
140. [True question] The combination of DnaA and the replicator is sequence-specific
A. Correct
B. Incorrect
reference material [ ]
141. [True question] Escherichia coli, yeast and eukaryotes A new round of viral DNA replication is initiated at a specific site, which is composed of several short sequences that can be used to bind the initial protein A, correct B, and incorrect reference materials [ ] 142,
[
Judgment
Questions
] 】The single-strand binding protein on the replication fork separates the two strands of DNA by covering bases, thus avoiding base pairing
A, correct
B, and
error
Synthesized in the 5'→3' direction, and the DNA fragments are synthesized in the 3'→5' direction on the lagging strand.
A. Correct
B. Incorrect
Reference materials 【 】