MCQ BIOTECHNOLOGY

                 BIOTECHNOLOGY

1) Which one of the following microscopic techniques is best suited to visualize the topology and distribution of transmembrane protein of a cell membrane!

(a) Scanning electron microscopy

(b) Transmission electron microscopy

(c) Freeze-fracture electron microscopy

(d) Thin-section electron microscopy

2) Which of the following compounds mimics aminoacyl 1-RNA and blocks protei

n synthesis?

(a) Puromycin 

(b)Kirromycin 

(c) Streptomycin 

(d) Neomycin

3) A novel type II restriction enzyme has been isolated from a thermophilic bacteria. This restriction endonuclease recognizes 5' ATAANNNTTAT 3' (N=any nucleotide) and cuts after third 'A' in the above sequence. What is the fate of DNA after restriction digestion?

(a) a 3 nucleotide long 5' overhang 

(b) a 7 nucleotide long 5' overhang

(c) a 4 nucleotide long 5' overhang 

(d) a 3 nucleotide long 3' overhang

4) Pyrosequencing derives its name from the fact that

(a) the bases are detected by pyrolysis

(b) it uses enzyme apyrase to detect the bases

(c) it detects pyrophosphate released during base incorporation

(d) it generates programs as output

5) A mammalian cell has an outstretched double stranded DNA of 1.2 meter which duplicates in 4 hours. If it duplicates at the rate of 20umeter/min, how many origins of replication are there in the DNA?

(a) 2500 

(b) 250 

(c) 25 

(d) 1

6) cis-trans isomerization of the peptide bond preceding an amino acid X is known to be critical in the folding of proteins by slowing down the folding reaction. The amino acid X is

(a) isoleucine 

(b) tryptophan 

(c) proline 

(d) histidine

7) Archea is considered as a separate group from bacteria and eukaryotes, due to

(a) genome sequence

(b) 16S rRNA gene sequence

(c) 23s rRNA gene sequence

(d) EETu sequence

8)Gene silencing is generally termed as

(a)switching off 

(b)switching on 

(c)absence 

(d)presence of genes

9)Selectable marker are

(a)antigenic

(b)antimetabolite

(c)immunity resistance 

(d)antihaemorhagic.

10) In presence of a significant quantity of IFN Y, what will be the response of a T-cell to an antigen presenting cell?

(a) T cell will become anergic

(b) T cell will get activated and start secreting IEN Y

(c) T cell will get activated and start secreting IL4

(d) T cell will become aT cytotoxic cell.

11)An extracellular ligand will be response in all types of cells because receptors have to be

(a) elicit the same response in various cells that have a receptor for the ligand

(b) elicit the same response but to varying degree in various cells that have a receptor for the ligand

(C) may elicit different responses in various cells that have a receptor for the ligand

(d) elicit the identical to bind to the same ligand.

12) Elevation of intracellular inositol triphosphate (IP3) results in the release of Ca from which of the following organelles?

(a) Mitochondria

(b) Smooth endoplasmic reticulum

(c) Peroxisome

(d) Golgi-complex

13) Antibodies which can cross placenta and are involved in allergic reactions, respectively are

(a) IgG and IgA

(b) IgM and IgE 

(c) IgG and IgE 

(d) IgD and IgM

14) Somatic mutations of immunoglobulin genes account for

(a) allelic exclusion

(c) affinity maturation

(b) class switching from IgM to IgG

(d) class switching from IgG to IgA

15) Yellow mosaic of legumes is caused by Mung bean yellow mosaic virus which belongs to

(a) potexvirus group

(b) potyvirus group

(c) arlavirus group 3

(d) geminiviruses group

16) Cell cycle progression from one phase to another is primarily controlled by

(a) phosphorylation of cyclin

(b) proteolysis of cyclin

(c) dephosphorylation of cyclin

(d) proteolysis of cyclin dependent kinase

17) When immature B cells mature in the bone marrow, they need to interact

(a) with stem cells present in the bone marrow

(b) with stromal cells and cytokinesie such as IL 7

(c) with mature B cells present in the bone marrow

(d) with antigen presenting cells with different B cells epitopes presented on MHC II molecules

18) Resting membrane potential of a biological membrane is close to the theoretical Nernst potential for the ions that are

(a)least abundant 

(b)most abundant 

(c)impermeable 

(d)permeable

19) Testosterone hormone necessary for spermatogenesis is secreted by

(a) sertoli cells 

(b) leydig cells 

(c) spermatozoa 

(d) cowpers gland

20) When Hfr strain of E. coli is crossed with F+ strain, recombinants obtained are

(a) always F+

(b) always Hfr 

(c) rarely F+ 

(d) rarely Hfr

21) Which one of the following viruses does not replicate in the cytoplasm of host cells?

(a) Picornaviruses, e.g., poliovirus 

(b) Poxviruses, e.g., vaccinia virus

(c) Rhabdoviruses, e.g., rabis virus 

(d) Hepadnaviruses, e.g., hepatitis B virus

22) Which one of the following statements is incorrect about Retroviruses?

(a)Retroviruses are the only family of viruses to encode Reverse Trascriptase

(b)They are the only RNA viruses whose genome is produced by cellular transcription machinery

(C) They are the only (+) sense RNA viruses whose genome does not serve directly as m RNA immediately after infection

(d) They have high mutation rates

23) Which one of the following organisms is used in Ames test?

(a) E. coli

(b) Streptococcus aureus

(c) Pseudomonas aerogenosa

(d) Salmonella typhimurium

24) Which of the following protozoan parasites replicates inside the lysosomes?

(a) Toxoplasma 

(b) Leishmania 

(c) Trypanosoma

(d) Plasmodium

25) Which one of the following repetitive motifs is responsible for the formation of triple helix in collagen?

(a) Ala-X-Y 

(b) Gly-X-Y

(c) Cys-X-Y 

(d) Pro-X-y

26) Which of the following processes occurs in the formation of disulfide bridge between two cysteine residues?

(a) Reduction of sulfhydral group

(c) Oxidation of sulnhydral grop

(b) Electrostatic interaction

(d) Hydrogen bond formation

27) Electrophoresis of a purified protein in SDS-PAGE in the presence of 2-marcaptoethanol yields two bands of 35 kDa and 45 kDa. However, in a gelfiltration chromatography, the same protein elutes as 80 kDa. What conclusion can be drawn from the above observation?

(a) Protein is not purified to homogeneity

(6) Two bands generated in SDS-PAGE due to degradation

(c) Protein is a multimer

(d) Protein is a heterodimer

28) Cholesterol contributes to which of the following properties of biological membranes?

(a) Membrane rigidity

(c) Membrane permeability

(b) Membrane fluidity

(d) Membrane osmolarity

29) Active site of all serine proteases consists of

(a) Ser-Glu-Asp 

(b) Ser-Glu-Met 

(c)Ser-His-Asp 

(d) Ala-Glu-Met

30) Which one of the following statements is not about chemokines?

(a) They are small molecular weight proteins

(b) They may bind to more than one receptor type

(c) They are secreted only by activated 1T-cells

(d) They are secreted by leukocytes

31) Sodium dodcyl sulphate, an anionic detergent commonly used in SDS-Polyacrylamide gel clectrophoresis, works in facilitating electrophoretic separation of a mixture of proteins by its ability to bind to the

(a) negatively charged amino acid side chains in proteins

(b) hydrophobic side chains in proteins

(C) positively charged amino acid side chains in proteins

(d) peptide group in protein

32) A BSA stock solution is diluted 10 folds with phosphate buffer. The adsorbance of the solution in a quartz cuvette of path length 1mm at 281.5 nm is 0.330. If the extinction coefficient of the protein is 0.66ml/mg.cm, the concentration of the stock protein solution would be

(a) 5mg/ml

(b) 20mg/ml 

(c) 33mg/ml 

(d) 50mg/ml

33) Which of the following properties is common to all cytoskeletal motor proteins like kinesins, dyneins, and mytosins?

(a) GTPase activity

(b) ATPase activity

(c) Actin binding domain 

(d) DNA binding domain.

34) Which of the following statements is correct for a reaction A+B - AB?

(a) Larger the value of the equilibrium constant, weaker is the binding between A and B

(b) Lower the value of the equilibrium constant, stronger is the binding between A  and B

(c) Larger the value of the equilibrium constant, stronger is the binding between A and B

(d) This is a third order reaction

35) The amino acids with Phi and Psi values (-60, -40); (-59,-47) and (-80, 120) will be adopting which of the following conformation?

(a) Helix-helix-extended

(b) Helix-coil-extended

(c) Extended-extended-loop

(d) Loop-loop-coil

36) Regulation of fatty acid biosynthesis occurs at the enzymatic step catalyzed by

(a) carnitine acyltransferase I 

(b) acetyl CoA carboxylase

(C) pyruvate carboxylase 

(d) citrate synthase

37) Which of the following is a lipid with a signal transducing activity?

(a) Phosphatidyl ethanolamine 5

(b)Phosphatidyl serine

(c) Phosphatidyl inositol 4,5-biphosphate 

(d) Phospholipase A2

38) The amino acid sequence of a novel membrane protein contains four immunoglobulin like domains and six fibronectin like repeats. This protein is most likely a

(a) hormone responsive ion channel 

(b) cell adhesion molecule

(c) G-protein

(d) transcription factor

39) Which one of the following antibiotics attaches to 50s ribosome and inhibits peptidyl-transferase activity?

(a) Penicillin 

(b) Chloramphenicol 

(c) Trimethoprin 

(d) Amphotericin

40) In a population of 200 individuals which is at equilibrium, the frequency of one of the alleles under study is 0.11. What is the expected frequency of heterozygous individuall?

(a) 0.89

(b) 0.0979

(c) 0.1958

(d) 0.842

41) Increased genetic diversity following extended time in a tissue culture is a problem called

(a) gene alteration

(b) temporal modification

(c)somaclonal variation

(d) culture shock

42) To produce plants that are homozygous for all traits, the best choice is

(a) cell suspension culture

(C) anther/ pollen culture

(b) callus culture

(d) plant organ culture

43) Dye injected into a plant cell might be able to enter an adjacent cell through

(a) tight junction

(b) microtubule 

(c) desmosome 

(d) plasmodesma

44) If you want to use a plant tissue culture as a chemical factory for vitamins,which of the following will you choose?

(a) Suspension cultures

(b) Organ cultures

(c) Callus cultures

(d) Anther/pollen cultures

45) In which one of the following fermentations an inhibitor is added to increase the productivity?

(a) Rifamycin B fermentation 

(b) Tetracycline fermentation

(C) Glutamic acid fermentation

(d) Citric acid fermentation

46) ) A computer separates an organization's internal network from the public part through a

(a)firewall 

(b)circuit-level gateway 

(c)security domains 

(d) interior node

47) A dNTP master mix is prepared by combining 50ul each of 10mM dNTP stock. Two micro liters from this dNTP mix are added to the PCR master mix of 25ul reaction volume. What is the total dNTP concentration in the PCR reaction?

(a) 200um

(b) 400um

(C) 800umn

(d) 250um

48)In which of the following cases, the enzyme substrate complex is irreversible in nature?

(a) Competetive inhibition

(c) Un competitive inhibition

(b) Non competitive inhibition

(d) Both a and b

49) A set of closely related genes or genetic markers that are inherited as a single unit is

(a) Cistron 

(b) Gene families 

(c) Haplotype

(d) Haploid

50) Which of the following stages of embryos is used for transfer into cows?

(a) Mid morula

(c) Very early morula stage

(b) Late nmorula stage

(d) Blastocyst stage