General Microbiology Multiple Choice Questions

MCQ-General Microbiology 

1.                  Cell wall synthesis during cell growth involves insertion of what material into the existing wall material.

a.                   DAP.                                                   b.         Peptidoglycan.

c.         bactoprenol.                                        d.         lipopolysaccharide.

2.                  Heat stable proteins tend to have………. which probably leads to more……..

a.                   Hydrophilic cores / ionic dispersal of particles which would normally cluster.

b.                  Hydrophobic cores / "salt bridges" between hydrophilic amino acids on the surface.

c.                   Hydrophobic cores / ionic dispersal of particles which would normally cluster.

d.                  Hydrophilic cores / "salt bridges" between hydrophilic amino acids on the surface.

3.                  The significance of Hopanoids in  the plasma membrane is that

a.                   It selectively allows some molecules to pass into the organism

b.                  It prevents movement of molecules out of the organism

c.                   It provides the elasticity to the membrane                  d.         All of the above

4.                  Arrange the following terms in the order they would be found if you traveled from the cytoplasm to the external medium of a Gram negative cell possessing a capsule:

1. periplasmic space                            2. phospholipid bilayer of the outer membrane

3. O-polysaccharide                            4. cytoplasmic membrane

5. capsule

a.                   4,3,1,2,5                                  b.         4,1,2,3,5

c.         5,2,3,1,4                                  d.         5,3,2,1,4

5.                  Osmotolerant yeasts are able to grow at high salt concentrations because their cytoplasm contains high concentrations of

a.                   High sodium ions

b.                  Amino acids.

c.                   Lipids.                                     d.         polyalcohols like glycerol

6.                  Magnetosomes, glycogen, polyphosphate and poly-beta-hydoxybutyric acid are all types of:

a.                   Storage products.       

b.                  Cytoplasmic inclusions.

c.                   Cell wall inclusions

d.                  Both b and c

7.                  Presence of sodium taulocholate in Mc Conkey agar makes the media

a.                   Differential media

b.                  Basal media

c.                   Selective media

d.                  Enriched media

8.                  What is the main function of central mesosome in Gram positive bacteria?

a.                   Site of protein synthesis.

b.                  Transport of extracelluar enzymes outside the cell wall

c.                   Taking part in cell division and DNA replication

d.                  Protect the cell membrane from injuries

9.                  The third amino acid in the peptidoglycan crosslinking chain is either diaminopamilic acid or lysine because this amino acid must

a.                   Be positively charged for a salt bridge to form.

b.                  Be hydrophillic.

c.                   Have a free amino group for peptide bond formation.

d.                  Have a large R-side chain to fill space in the cell wall.

10.              The outer membrane of Gram negative cells is more permeable than the plasma membrane because

a.                   LPS is larger than most membrane phospholipids.

b.                  Lipoproteins stretch the outer membrane.

c.                   Porin proteins establish holes in the outer membrane.

d.                  The core polysaccharide spans the lipid bilayer.

11.              The bacterial capsule

a.                   may be antigenic

b.                  is required for cell viability

c.                   is involved in motility.

d.                  may contribute to a bacterium's pathogenicity

12.              Bacterial pili may enhance virulence of bacterial pathogens by

a.                   Transporting nutrients            

b.         providing a means of attachment

c.         increasing the surface area of bacteria.          

d.         being an endotoxin

13.              An aquatic bacterium with a polysaccharide capsule for attachment and virulence is

a.                   Stella spp.                                                        b.         Caulobacter spp.

c.         Streptococcus mutans                         d.         Sphaerotilus natans

14.              Which of the following statements about bacterial flagella is incorrect?

a.                   The locomotion caused by flagella can be directed to move cells toward a source of   nutrients.

b.                  The filaments are composed of protein subunits called flagellin.

c.                   The flagella move cells by acting as propellers.

d.                  All motile bacteria have flagella

e.                   Flagella increase in length by adding new material to the tip not the base

15.              Transformation includes all of the following except

a.                   Plasmids.

b.                  Sex pili.

c.                   Competent cell.

d.                  Naked DNA.

16.              Hfr bacteria

a.                   Are derived from F ⁺ bacteria.                                               

b.                  Functions as donor in crosses with F^- bacteria 40°C.

c.                   Functions as donor in crosses with F^- bacteria 40°C and are so called because they result in high frequency recombination

d.                  are so called because they result in high frequency recombination

17.              Preserve foods by using salts and sugars works by

a.                   Depleting nutrients.                                        b.         Lowering osmotic pressure.

c.         Creating a hypertonic environment.    d.         Creating a hypotonic environment.

18.              Which one of the following forms of immunity to viruses would be least likely to be life long?

a.         Passive immunity                                            b.         Passive-active immunity

c.         Active immunity                                             d.         Cell mediated immunity

19.              Which one of the following is not true for virus, obligate intracellular parasites?

a.                   Viruses cannot generate energy outside of cells

b.                  Viruses cannot synthesize proteins outside of cells

c.                   Viruses must degrade host cell DNA in order to obtain nucleotides

d.                  Enveloped viruses require host cell membrane to obtain their envelopes

20.              Each of the following statement of lysogeny is correct except

a.                   Viral genes replicate independently of bacterial genes

b.                  Viral genes responsible for lysis are repressed

c.                   Viral DNA is integrated into bacterial DNA

d.                  Some lysogenic phages encode toxins that cause human disease

21.              The genome of rhabdoviruses consists of a single-stranded RNA molecule whose sequence is complementary to the RNA sequence which functions as a messenger RNA. How is the "+ sense" messenger RNA produced in cells infected by rhabdovirus?

a.                               one portion of the infecting RNA is directly translated by host cell ribosomes

b.                  host cell RNA polymerase activity

c.                   reverse transcriptase activity

d.                  the infecting virus particle contains an RNA-dependent RNA polymerase

22.              An E. coli cell which carries a lambda prophage is immune to a lytic infection by a second lambda virus because:

a.                   The second virus cannot inject its DNA

b.                  proteins from the prophage's lytic genetic program prevent replication of the second virus

c.                   proteins from the prophage's lysogenic genetic program prevent replication of the second virus

d.                  the second virus cannot adsorb to the cell

23.              Which of the following methods will not sterilize?

a.                   500 mg/L ethylene oxide at 50⁰C for 4 hours

b.                  Dry heat at 171⁰C for 1 to 2 hours

c.                   121⁰C at 15 lb/in pressure for 15 to 20 minutes

d.                  100⁰C boiling water for 30 minutes

24.              Which of the following is bactericidal?

a.                   Ionizing radiation                    b.         Freeze-drying              c.         Deep freezing

d.         All of these processes kill bacteria.

25.              Which of the following is most effective for sterilizing mattresses and plastic Petri plates?

a.                   Ethylene oxide                                                b.         Glutaraldehyde

c.         Autoclave                                                        d.         Ultraviolet radiation

Use this information to answer the following question(s): Q. 26
	Phenol Coefficient
Compound	Salmonella typhi	Staphylococcus aureus
Phenol	1	1
Cetylpyridinium chloride	228	337
Hexachlorophene	5-15	15-40
Merthiolate	600	62.5
Ethanol	0.04	0.04

MULTIPLE CHOICE QUESTIONS FOR M.SC. MICROBIOLOGY ENTRANCE EXAM PREPARATION, TU, 2012 (SUBJECT: INSTRUMENTATION & BIOCHEMISTRY)

MULTIPLE CHOICE QUESTIONS : INSTRUMENTATION and BIOCHEMISTRY

1.        Percent (%) solution of any compound is prepared by

a.        w/w

b.        w/v

c.        v/v

d.        All

2.        One gram  equivalent weight per liter of solution is known as

a.        1 M solution

b.        1 N solution

c.        Concentrated solution

d.        Saturated solution

3.        95 % pure HCl with sp. Gravity=1,080 g/L has how many molar HCl?

a.        29.6 M

b.        28.11 M

c.        25 M

d.        6 M

4.        1 ppm (parts per million) is equivalent to

a.        1 mg/L

b.        1 g/L

c.        1 mg/100 mL

d.        1 mg/L

5.        Which of the following solutions are equal in concentration?

a.        1 N HCl & 1 M H₂SO₄

b.        2 N HCl & 1N HNO₃

c.        2 N HCl & 1 M H₂SO₄

d.        All

6.        50 ml 0.2 M of KH₂PO₄ is mixed with 50 ml of K₂HPO₄ to make final volume 200 ml, what is the final molarity of the mixture?

a.        0.2 M

b.        0.1 M

c.        0.4 M

d.        None

7.        Phosphate buffer has ………………. pKa values

a.        1

b.        2

c.        3

d.        4

8.        What are the components of Acetate buffer?

a.        CH₃COOH & CH₃COONa

b.        CH₃COOH & H₂O

c.        CH₃COONa & H₂O

d.        CH₃COONa & HCOOH

9.        The pKa value of acetate buffer is

a.        1.25

b.        7.60

c.        4.76

d.        9.25

10.     The pH adjustment of phosphate buffer can’t be done by

a.        1 N HCl

b.        1 N H₃PO₄

c.        1 NaOH

d.        None

11.     Buffer used for DNA preparation is

a.        Carbonate buffer

b.        Phosphate buffer

c.        Citrate buffer

d.        Tris buffer

12.     Which one cell is the strongest cell against mechanical cell disruption?

a.        Gm + cell

b.        Gm – cell

c.        Yeast cell

d.        Plant cell

13.     Extraction of which biomolecule don’t need cell disintegration?

a.        DNA

b.        Ribozyme

c.        Integral protein

d.        Antibiotics

14.     The clearance space of Dounce’s homogenizer ranges from

a.        0.1 mm – 0.6 mm

b.        1 mm – 6 mm

c.        0.001 mm – 0.006 mm

d.        1 nm -  6 nm

15.     The ultrasonic vibrations have frequency of

a.        Below 20 Hz

b.        Above 20 KHz

c.        Equivalent to 10,000 Hz

d.        Above 50 MHz

16.     Lysozyme breaks down the bond in cell wall.

a.        a 1-4 glycosidic bond in between NAG and NAM

b.        a 1-4 glycosidic bond in between NAM and NAG

c.        b 1-4 glycosidic bond in between NAG and NAM

d.        b 1-4 glycosidic bond in between NAM and NAG

17.     Protein precipitation by salting out can be best obtained by

a.        NaCl

b.        NH₄Cl

c.        (NH4)₂SO₄

d.        Na-citrate

18.     The saturated solution of NaCl is used to precipitate

a.        Albumin only

b.        Globulin only

c.        Both

d.        None

19.     The ionic strength of 1 N (NH4)₂SO₄ is equivalent to

a.        1

b.        2

c.        3

d.        4

20.     The most effective anion in salting out is

a.        SO₄^¯¯

b.        PO₄^¯¯¯

c.        Cl¯

d.        NO₃¯

21.     At isoelectric point, a protein has its

a.        Maximal solubility

b.        Minimum solubility

c.        Maximum charge

d.        Minimum activity

22.     Denaturation of proteins leads to loss of biological activity by

a.        Formation of amino acid

b.        Loss of primary structure

c.        Loss of both primary and secondary structure

d.        Loss of secondary and tertiary structure

23.     Which one of the following is not a protein determination method?

a.        Biuret method

b.        Barfoed method

c.        Lowry method

d.        Bicinchonic acid method

24.     The purity of an enzyme at various stages of purification is best measured by:

a.        Total protein

b.        Total enzyme activity

c.        Specific activity of the enzyme

d.        Percent recovery of protein

25.     The sensitivity of CBB G250 Dye binding method is

a.        > 1 mg

b.        > 1 mg

c.        > 1 Ng

d.        > 1 g

26.     The quantization of DNA and protein by UV method is done at

a.        265 nm & 300 nm

b.        450 nm & 595 nm

c.        260 nm and 280 nm

d.        190 nm & 260 nm

27.     The absorbance in Lowry method is measured at

a.        595 nm

b.        660 nm

c.        280 nm

d.        450 nm

28.     Proteins absorbs maximally UV radiation due to the presence of

a.        Tryptophan

b.        Tyrosine

c.        Phenyl alanine

d.        All of the above