MICROBIOLOGY-2
51. The bases Adenine and Thymine are paired with
a. Double hydrogen bonds
b. Single hydrogen bonds
c. Triple hydrogen bonds
d. Both b and c
52. The no. of hydrogen bonds existing between Guanine and Cytosine are
a. 5
b. 2
c. 3
d. None of these
53. The length of each coil in DNA strand is
a. 15 Ao
b. 34 Ao
c. 30 Ao
d. 5 Ao
54. Nucleic acids are highly charged polymers due to
a. There is phosphodiester bond between 5’- hydroxyl of one ribose and 3’–hydroxyl of next ribose
b. They have positive and negative ends
c. Nucleotides are charged structures
d. Nitrogenous bases are highly ionized compounds
55. The best studied example for specialized transduction is
a. P1 phage
b. P22 phage
c. λ Phage
d. Both a and c
56. The diagrammatic representation of the total no. of genes in DNA is
a. Genome
b. Gene map
c. Gene-structure
d. Chromatin
57. During specialized transduction
a. Large amount of DNA is transferred
b. A few no. of genes are transferred
c. Whole DNA is transferred
d. None of these
58. The cell donating DNA during transformation is
a. Endogenate
b. Exogenate
c. Mesozygote
d. Merosite
59. Genetic information transfer DNA to RNA is called –
a. Transcriptase
b. Transduction
c. Transformation
d. Recombination
60. The gene transfer occurs by –
a. Transformation
b. Transduction
c. Conjugation
d. Cell fusion
61. Multiple antibiotic resistance is mediated by
a. Episome
b. Plasmid
c. Colplasmid
d. Both b and c
62. “Antagonism “is seen in
a. Lag phase
b. Plasmids
c. Log phase
d. None of these
63. The first phase of a growth curve is
a. Log phase
b. Lag phase
c. γ phase
d. Both a and b
64. In gram positive and gram negative bacteria the electron transport contains
a. Naphthquinone
b. Plastoquinone
c. Ubiquinone
d. Both a and b
65. Growth in a closed system, affected by nutrient limitation and waste product accumulation is called
a. Batch culturing
b. Ascus
c. Fruiting body
d. Sporangiosphore
66. Cells are active and synthesizing new protoplasm. This stage of growth is called
a. Lag phase
b. Stationary phase
c. Log phase
d. All of these
67. Which one of the following tissues can metabolize glucose, fatty acids and ketone bodies for ATP production?
a. Liver
b. Muscle
c. Brain
d. R.B.C
68. Which one of the following mineral elements play an important role in biological nitrogen fixation
a. Copper
b. Magnesium
c. Zinc
d. Molybdenum
69. Rapid bacterial growth phase is known as
a. Log
b. Lag
c. Lack
d. None of these
70. Clostridium welchii spore formation can be induced only on specified media such as
a. Wilson-Blair medium
b. Macconkey medium
c. Ellner medium
d. Thayee-Martion medium
71. Mycotoxins are formed during the end of
a. Lag phase
b. Log phase
c. Death phase
d. Stationary phase
72. Bacteria which need oxygen for growth are called
a. Thermophilic bacteria
b. Microaerophilic bacteria
c. Facultative anaerobic bacteria
d. Mycobacteria
73. pH required for the growth of bacteria is
a. 6.8 – 7.2
b. 5.6 – 8.2
c. 3.0 – 6.0
d. 8.0 – 14.0
74. Drug resistance in bacteria is mainly determined by factor:
a. F
b. R
c. Col
d. Lysogenic factor
75. The ion that is required in trace amounts for the growth of bacteria is
a. Calcium
b. Magnesium
c. Cobalt
d. Sodium
76. The most important vitamin for the growth of bacteria is
a. B-complex
b. Vitamin A
c. Vitamin D
d. Vitamin C
77. The principle in microbiological assays is
a. At certain range the concentration of growth factor will bear a linear relationship to the amount of nutrients added
b. Concentration of growth factor have a linear relationship with the growth of the organism
c. Both a and b
d. None of the above
78. If the source of energy for bacteria is from chemical compounds they are said to be
a. Phototrophs
b. Autotrophs
c. Chemotrophs
d. Chemolithotroph
79. In the synthesis of cell components the major element required is
a. Nitrogen
b. Sulphur
c. Carbon
d. Oxygen
80. For the formation of cell-components the elements required are
a. Nitrogen
b. Oxygen
c. Sulphur
d. All of these
81. For the synthesis of amino acids cysteine, cystine and methionine the element required is
a. Sulphur
b. Oxygen
c. Nitrogen
d. None of these
82. Sulphur can be utilized by bacteria in the form of
a. Organic compounds
b. Inorganic compounds
c. Elemental compounds
d. All of the above
83. Phosphorous is an essential component of
a. Nucleotides
b. Nucleic acids
c. Phospholipids and Teichoic acids
d. All the above
84. Trace elements are
a. Zn+2, Cu+2, Mn+2
b. MO6+, Ni2+, B3+ and CO2+
c. Both a and b
d. None of these
85. Most bacteria do not require the ion
a. Mg2+
b. Ca2+
c. Na+
d. Fe+2
86. Vitamin function as
a. Co-enzymes
b. Co-melecules
c. Building blocks of cell
d. None of these
ANS:- A and C
87. The vitamin required for Lactobacillus species is
a. Riboflavin
b. Niacin
c. Pyridoxine
d. Folic acid
88. Vitamin K is necessary for the species
a. Lactobacillus spp.
b. Bacillus anthracis
c. Bacteroides melaninogenicus
d. All of these
89. The bacteria which are able to grow at 0°C but which grow at 20°C to 30°C, are known as
a. Psychrophiles
b. Facultative psychrophiles
c. Average psychrophiles
d. Mesophiles
90. Radical shifts can be prevented by adding
a. Acids
b. Alkali
c. Buffer
d. None of these
91. The orderly increase in the quantity of all the cellular components is known as
a. Reproduction
b. Growth
c. Binary fission
d. None of these
92. The most common mode of cell division in bacteria is
a. Binary fission
b. Transverse binary fission
c. Longitudinal binary fission
d. None of these
93. How much time a bacterium take for the complete duplication?
a. 30 min.
b. 10 min.
c. 20 min.
d. 25 min.
94. The generation time is
a. The time required for the cell to divide
b. The total division of the cell during its life time
c. The total no.of cells formed
d. None of these
95. In bacteria, the increase in population is in the manner
a. Geometric progression
b. Multiplication
c. Doubling
d. None of these
96. Physiologically the cells are active and are synthesizing new protoplasm in which stage of the growth in bacteria
a. Log phase
b. Lag phase
c. Stationary phase
d. None of these
97. The most active stage in the sigmoid curve of bacteria in which maximum growth is attained
a. Lag phase
b. Stationary phase
c. Decline phase
d. Log phase
98. Log-phase is also known as
a. Death phase
b. Exponential phase
c. Lag-phase
d. None
99. The no. of generations per hour in a bacteria is
a. Growth rate
b. Generation time
c. Sigmoid curve
d. None of these
100. In the sigmoid curve (or) growth curve of bacteria how many stages are there
a. 3
b. 4
c. 2
d. 5
