Department. Zoology & Biotechnology QUESTION BANK BIOTECHNOLOGY SEMESTER-V

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1 Department of Zoology & Biotechnology QUESTION BANK BIOTECHNOLOGY SEMESTER-V

2 Unit-1 Genetic Material Different forms of DNA(DNA topology):- B-form, Z-form, D-form; Gene structure-introns,exaons and pseudogenes: Supercoiling of DNA, Melting curve of DNA and Tm value determination; Buoyant density of DNA and its relationship with mole (G+C) content in DNA; Types of RNA: mrna, rrna, trna;, Organization of Eukaryotic genome wsr Cot value. MCQ 1. DNA, as genetic material/transforming principle was experimently proved by which of the following scientists? a. Friedrick Meischer and Griffith b. Watson and Crick c. Rosalin and Willkins d. Avery Mcleod and Mc Carty 2. Double helical structure of dna was given by which of the following scientists a. Watson and crick b. Rosalin and wilkins c. Barbara Mc Clintock d. Avery Mcleod and Mc Carty 3. Which of the following statements is not true according to chargaff s rule a. All the cells of an oeganism or a tissue have identical or closely similar base composition b. Different organisms exhibit wide variation in the base composition which is expressed in the ratio (A+T)/ (G+C) c. Similar base composition are exhibited by closely related organisms. d. According to chargraff rule A=G and T=C 4. The breaking of hydrogen bonds in a dna molecule when subjected to high temperature is known as a. Renaturation b. Denaturation c. Annealing d. Ionisation 5. Clover leaf model of secondary of rna was given by a. Taylor b. Mckinskey c. Holly d. Hudson 2 Page

3 SHORT ANSWER TYPE QUESTION 1. What is B-form of DNA? 2. Write a note on gene structure? 3. Write a note on Supercoiling of DNA? 4. What is Melting curve of DNA and Tm value. 5. What are pseudogenes? LONG ANSWER TYPE QUESTION 1. Explain different types of RNA? 2. Explain exons and introns? 3. Explain the organization of eukaryotic genome? 4. Write a note on different forms of DNA? 5. Explain the buoyant density of DNA and its relationship with mole (G+C) content in DNA? 3 Page

4 Unit-2 DNA Replication Types of DNA replication: Conservative, Semi-conservative and Dispersive mode of replication; Mechanism of replication, Messelson and Stahl experiment; Enzymes involved in replication of DNA; Replication of DNA in prokaryotes and eukaryotes, Models of chromosomal replication- Cairns model, Rolling Circle model. MCQ 1. 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 consist of segments of new and parental DNA. C. The double helices in each daughter cell consist of one parental strand and one newly made strand. 2. What kinds of bonds link the two strands of a double helix to each other? A. Covalent bonds B. Hydrogen bonds C. Ionic bonds D. Phosphodiester 3. Replication origins typically consist 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. 4. Which term describes DNA replication? A. Conservative B. Semiconservative C. Dispersive D. None of these. 4 Page

5 SHORT ANSWER TYPE QUESTION 1. Write a note on semi conservative mode of dna replication? 2. Write a note on Messelson and Stahl experiment? 3. Write a note DNA polymerase? 4. Write a note Cairns model of replication. 5. Write a note Okazaki fragment. LONG ANSWER TYPE QUESTION 1. Explain the DNA replication in eukaryotes? 2. Explain the DNA replication in prokaryotes? 3. Write a long note on the chromosomal replication model? 4. Write a long note on enzymes used in the DNA replication? 5. draw a neat diagram of general model of replication. 5 Page

6 Unit-3 Transcription, Translation and Gene regulation Synthesis of RNA; Transcription signals; Mechanism of transcription in prokaryotes and eukaryotes; Post transcriptional modification- basic concepts Translation and Gene regulation in prokaryotes:- Outline of translation; Requirements of translation; Genetic Code: Basic features of genetic code, Wobble hypothesis, Overlapping genes, deciphering of genetic code, Ribosomes: there general nature and role in protein synthesis, charging of trnas, initiation, elongation and termination of protein synthesis in prokaryotes; post translational modification of polypeptides; regulation of protein synthesis; Lac operon. MCQ 1. RNA is synthesized on a DNA template in a process called, which utilizes the enzyme a. translation, RNA polymerase b. transcription, DNA polymerase c. transcription, RNA polymerase d. replication, DNA polymerase 2. Which of the following is NOT a necessary component of translation? a. anticodon b. mrna c. ligase d. amino acid 3. Okazaki fragments occur on the and are bonded together by a. leading strand, polymerase b. mrna, anticodons c. lagging strand, ligase d. trna, polymerase 4. Which molecule contains the genetic code? a. DNA b. mrna c. trna d. rrna 5. Once transcription has been completed, which of the following is NOT necessary for protein synthesis to occur? a. trna b. ribosomes c. mrna d. DNA 6 Page

7 SHORT ANSWER TYPE QUESTION 1. Write note on Lac operon? 2. What is wobble hypothesis? 3. What is the function of ribosome? 4. Write a note on the elongation of transcription in eukaryotic? LONG ANSWER TYPE QUESTION 1. Write a long note on transcription? 2. Write a long note on translation? 3. Write a note on basic features of genetic code. 4. Explain the post translational modification. 7 Page

8 Unit-4 DNA mutation and repair Types of mutation; evidence of spontaneous nature of mutation: Luria and Delbruck fluctuation test and replica testing; mode of action of physical, chemical and biological mutagens-uv rays, nitrous acid, 5-bromouracil, 2-aminopurin, EMS. Reversion in mutation, true reversion, suppression and types of suppressor mutation; DNA repair mechanism, Photo reactivation, Excision, Mismatch, SOS repair. MCQ 1. Type of mutation in which a pyrimidine is substituted for a purine a. Transition b. Transversion c. Frameshift d. Conversion e. Inversion 2. Type of mutation caused by an addition or deletion of a base in a polypeptide-encoding part of a gene a. Transition b. Transversion c. Frameshift d. Conversion e. Inversion 3. A base change that changes a codon for an amino acid to a stop codon a. Missense b. Silent c. Nonsense d. Synonymous e. Frameshift 4. After mutagen treatment, a molecule of 2-aminopurine (an adenine analogue) incorporates into DNA. During replication the 2-AP protonates caussing it to base-pair like guanine. The mutational event caused by this will be a. AT to CG b. GC to AT 8 Page

9 c. AT to TA d. AT to GC e. GC to CG 5. A researcher studying hemoglobin predicts that a histidine within the protein is important for binding oxygen. She used site-directed mutagenesis to change a codon for histidine (CAU) to one for lysine (AAA). However, the mutant hemoglobin still binds oxygen just as well as the wild-type and has no other apparent changes. This type of mutation is called a. suppression b. synonymous c. nonsense d. silent e. frameshift SHORT ANSWER TYPE QUESTION 1. Write a note on Luria and Delbruck fluctuation test? 2. What is replica plate method? 3. Write mode of action of physical mutagens 4. Write mode of action of chemical and biological mutagens? 5. What is reversion in mutation? 6. What is photo reactivation DNA repair? LONG ANSWER TYPE QUESTION 1. Write a long note on types of mutation? 2. What is suppression mutation and types of suppressor mutation 3. Explain the DNA repair mechanism in general? 4. Write in detail about Base excision ans nucleotide excision repair? 5. What is mismatch repair? Explain with neat diagrams. 9 Page

10 Unit-5 Genetic engineering Recombinant DNA Technology- Definition, principle, Molecular tools of genetic engineering: Cutting and joining of DNA, Cloning Vectors, Techniques of genetic engineering, Gene library-genomic library and cdna library. Application of PCR technology (Diagnosis of pathogen, DNA fingerprinting.) Directed mutagenesis and protein engineering. 1. An enzyme that recognizes a specific (palindromic) sequence and cuts within a DNA molecule is called a(n): (a)exonuclease (b)methylase (c)modification enzyme (d)restriction endonuclease 2. The necessary ingredients for DNA synthesis can be mixed together in a test tube. The DNA polymerase is from Thermus aquaticus and the template is from a human cell. The DNA synthesized would be most similar to: (a)human DNA (b) T. aquaticus DNA (c)a mixture of T. aquaticus and human DNA (d)human RNA (e)t. aquaticus RNA 3. The amount of a specific DNA sequence can be increased more than 10 6 fold by using which of the following chemical reactions? (a)restriction endonuclease reaction (b)ligation reaction (c)polymerase chain reaction (d)reverse translation (e)reverse transcriptase reaction 4. Which polymerase made widespread use of PCR possible: (a)dna polymerase I (b)thermus aquaticus (Taq) polymerase (c)dna polymerase III (d)none of the above (e)all of the above 10 Page

11 5. Which is the correct order, from smallest to largest number of base pairs? (a)plasmid, transposon, chromosomal DNA (b)chromosomal DNA, transposon, plasmid (c)transposon, plasmid, chromosomal DNA (d)plasmid, chromosomal DNA transposon SHORT ANSWER TYPE QUESTION 1. What is side directed mutagenesis? 2. What is genomic library? 3. What is cdna library? 4. What are plasmid vectors? 5. What are endonucleases and exonuclease? LONG ANSWER TYPE QUESTION 1. What is recombinant DNA technology? Explain the molecular tool of genetic engineering? 2. Write a note on enzymes used in recombinant DNA technology? 3. What is PCR? Explain the applications of PCR? 4. What is protein engineering? 5. What is vector? Explain the characteristics of a good vector taking PBR322 as an example? 11 Page