7th-Biochemistry-Exam-DNA-and-RNA-Metabolism-Batch-2025 COPY Flashcards
1.True about the non-template strand except:
A. Strand that is transcribed
B. Also termed coding strand
C. Corresponds exactly to the sequence of RNA primary transcript except T for U
D. None of the above
A. Strand that is transcribed
2.The product of DNA transcription is called:
A. Mature mRNA
B. Introns
C. Primary transcript
D. Exons
C. Primary transcript
- Nonprotein coding RNA that participates in mRNA splicing:
A. miRNA
B. siRNA
C. snRNA
D. lncRNA
C. snRNA
4.The most abundant of all types of RNA comprising about 80% of the total:
A. mRNA
B. tRNA
C. snRNA
D. rRNA
D. rRNA
5.Similarities of DNA and RNA synthesis include the following except:
A. The general steps of initiation, elongation and termination with 5’ to 3’ polarity
B. Large multicomponent initiation complexes
C. Both have highly active efficient proofreading function
D. Adherence to Watson-Crick base-pairing principles
C. Both have highly active efficient proofreading function
6.This includes the promoter, RNA-coding region and a terminator:
A. Transcription unit
B. Primary transcript
C. 5’ Flanking sequences
D. 3’ Flanking sequences
A. Transcription unit
7.The RNA polymerase that has intermediate sensitivity to alpha-amanitin:
A. Pol I
B. Pol II
C. Pol III
D. Pol IV
C. Pol III
8.The major product/products of RNA Polymerase I is:
A. rRNA
B. mRNA, lncRNA,miRNA,snRNA
C. tRNA, 5s RNA
D. 45S RNA
A. rRNA
9.RNA polymerase attaches to this site to start the initiation process:
A. Guanosine triphosphate cap
B. Enhancer
C. Primer
D. Promoter
D. Promoter
10.All nucleotides upstream of the site of transcription termination are termed:
A. 5’ Flanking sequences
B. 3’ Flanking sequences
C. Pre-initiation complex
D. Closed complex
A. 5’ Flanking sequences
11.The type of RNA polymerase that catalyzes the synthesis of mRNA:
A. Pol I
B. Pol II
C. Pol III
D. Pol IV
B. Pol II
12.The TATA box in eukaryotes is located:
A. 10 bp upstream from the transcription start site (TSS)
B. 25-30 bp upstream from TSS
C. 35 bp upstream from the TSS
D. 5 bp upstream from the TSS
B. 25-30 bp upstream from TSS
13.The termination protein is also called:
A. Psi factor
B. Sigma factor
C. Alpha factor
D. Rho factor
D. Rho factor
14.In some mRNA encoding genes that lack a consensus TATA box, this directs the RNAP
A. Downstream promoter element
B. Enhancers
C. General transcription factors
D. Primer
A. Downstream promoter element
15.The general transcription factor (GTF) that binds to the TATA box promoter element:
A. TFIIA
B. TFIIB
C. TFIIC
D. TFIID
D. TFIID
16.Phosphorylation of Pol II results to:
A. Increased activity
B. Reduced activity
C. No change
D. Static activity
A. Increased activity
17.On certain eukaryotic genes, transcription machinery cannot access the promoter because they are wrapped in:
A. Spliceosomes
B. Ribosomes
C. Nucleosomes
D. Ribozymes
C. Nucleosomes
18.Processing of mRNA primarily occurs in the:
A. Cytoplasm
B. Ribosomes
C. Nucleus
D. Nucleolus
C. Nucleus
19.The RNA sequence that appears in mature RNAs:
A. Exons
B. Introns
C. Cap
D. Tail
A. Exons
20.Intervening sequences of DNA that neither appear in mature mRNA nor contribute to the genetic information:
A. Exons
B. Introns
C. Cap
D. Tail
B. Introns
21.Removal of intervening sequences and splicing together of final sequences are done by:
A. Spliceosome
B. Nucleosome
C. Ribosome
D. None
A. Spliceosome
22.In mammalian cells, the three rRNA molecules are transcribed as part of this single large precursor molecule:
A. 40S
B. 32S
C. 45S
D. 24S
C. 45S
23.The precursor rRNA molecule is processed in the:
A. Nucleus
B. Nucleolus
C. Ribosome
D. Mitochondria
B. Nucleolus
24.At the 5’end, mRNA molecules are capped with:
A. Poly (A) tail
B. TATA cap
C. 7-methylguanosine cap
D. GCCT tail
C. 7-methylguanosine cap
- RNA can also act as a catalyst in the form of:
A. Lysozymes
B. Ribozymes
C. Kinases
D. Topoisomerase
B. Ribozymes
26.Which of the following best describes semiconservative replication?
A. replication of DNA takes place at S phase of the cell cycle
B. a DNA molecule is a hybrid of an old strand and one new strand
C. number of DNA molecules is doubled with every other replication
D. replication of DNA never takes place with 100% accuracy
B. a DNA molecule is a hybrid of an old strand and one new strand
27.What consists of the final product of DNA replication?
A. mRNA, tRNA, and rRNA molecules
B. a wide variety of proteins
C. DNA molecule
D. 2 DNA molecules, each of which contains one new & one old DNA strand
D. 2 DNA molecules, each of which contains one new & one old DNA strand
28.Which method/technique was used by Messelson and Stahl to prove semi-conservative manner of replication?
A. equilibrium density gradient centrifugation
B. isopycnic centrifugation
C. differential centrifugation
D. differential radioisotope labeling
A. equilibrium density gradient centrifugation
29.Which of the following cause the unwinding of the DNA double helix in E. coli?
A. Dna A
B. Dna B
C. Dna C
D. Dna G
B. Dna B
30.Which describes the replication fork?
A. only seen in bacterial cells
B. a Y-shaped structure representing the separated strands of DNA to be replicated simultaneously
C. a site where one DNA strand serves as a template, but the other strand is not replicated
D. is created by the action of the enzyme RNA polymerase
B. a Y-shaped structure representing the separated strands of DNA to be replicated simultaneously
31.In replication, once the DNA strands have been separated, which prevents the renaturation of the DNA strands?
A. DNA helicase enzyme
B. SSB proteins
C. DNA polymerases
D.ATP
B. SSB proteins
32.Which enzymes form breaks in the DNA molecules preventing the formation of knots in the DNA helix during replication?
A. topoisomerases
B. DNA polymerases
C. RNA polymerases
D. DNA ligases
A. topoisomerases
33.Which of the following adds new nucleotides to a growing DNA chain?
A. DNA polymerase
B. DNA helicase
C. primase
D. RNA polymerase
A. DNA polymerase
34.Why does DNA synthesis only proceed in the 5´ to 3´ direction?
A. DNA polymerases can only add nucleotides to the 3´ end of a polynucleotide strand
B. the 3´ end of the polynucleotide molecule is more electronegative than the 5´ end
C. that is the direction in which the two strands of DNA unzip
D. that is the only direction that the polymerase can be oriented
A. DNA polymerases can only add nucleotides to the 3´ end of a polynucleotide strand
35.Which begins the 5´ end of each Okazaki fragments?
A. the same RNA primer that began synthesis on the leading strand
B. a DNA primer binding to the template DNA
C. DNA polymerase binding to the template DNA
D. a separate RNA primer
D. a separate RNA primer
36.What does a primase carry out in replication?
A. introducing nicks into the DNA double strand in order to prevent the formation of knots
B. hydrolyzing ATP to facilitate DNA unwinding
C. synthesizes short strands of RNA at the site of replication initiation
D. forming a replication fork in the DNA double helix
C. synthesizes short strands of RNA at the site of replication initiation
37.Which protein seals the nick in between Okazaki fragments?
A. RNA polymerase
B. DNA ligase
C. DNA polymerase
D. RNA ligase
B. DNA ligase
38.How is the chromosome of a bacterial cell replicated?
A. linear DNA molecule is replicated from multiple origins of replication bidirectionally.
B. linear DNA molecule is replicated from one origin of replication bidirectionally.
C. circular DNA molecule is replicated from one origin of replication bidirectionally
D. circular DNA molecule is replicated from one origin of replication Unidirectionally
C. circular DNA molecule is replicated from one origin of replication bidirectionally
39.Which is the manner by which eukaryotic cells replicate their chromosomes?
A. the linear DNA, from multiple origins of replication bidirectionally
B. the linear DNA, from one origin of replication bidirectionally
C. the circular DNA from multiple origins of replication bidirectionally
D. the circular DNA from one origin of replication bidirectionally
A. the linear DNA, from multiple origins of replication bidirectionally
40.Which is an important feature of the E. coli DNA polymerase III?
A. can initiate replication without a primer
B. is efficient at nick translation
C. is the major polymerizing enzyme in DNA replication
D. represents over 90% of the DNA polymerase activity in E. coli cells
C. is the major polymerizing enzyme in DNA replication