Tag: GATE Life Science Previous Year Papers with Solutions

78. Constitutive enzymes are (A) Induced by effector molecules (B) Repressed by repressors (C) Encoded by sequences that occur as part of an operon (D) Always produced in the cell […]

77. Which one of the following statements is TRUE when determining the age of a fossil using carbon dating? (A) Carbon dating is based on carbon-13 to carbon-12 ratio in […]

76. The term “paedomorphosis” refers to (A) Accelerated reproductive development as compared to somatic development (B) A transient stage in the developmental event (C) Two independent structures resembling each other, […]

75. An E. coli strain is grown initially on glucose as the sole carbon source. Upon complete consumption of glucose following 12 h of growth, lactose is added as the […]

74. The volume (in ml) of a 1.0mg/mlstock solution of ampicillin to be added to 0.1 liter of growth medium for achieving a final ampicillin concentration of 50𝜇 g/ml is […]

73. A bacterial culture is grown using 2.0mg/ml fructose as the sole source of carbon and energy. The bacterial biomass concentrations immediately after inoculation and at the end of the […]

72. The doubling time (in minutes) of a bacterium with a specific growth rate of 2.3 h−1 in 500 ml of growth medium is ____ Calculate Bacterial Doubling Time from […]

71. If the decimal reduction time for spores of a certain bacterium at 121∘C is 12 seconds, the time required (in minutes) to reduce 1010 spores to one spore by […]

70. The working volume (in liter) of a chemostat with 0.1 h−1 dilution rate and 100ml/h feed flow rate is ____ Chemostats are essential bioreactors in microbiology and biotechnology for […]

69. An oil immersion objective of a light microscope has a numerical aperture of 1.25 . Using the Abbé equation, the maximum theoretical resolving power (in nm) of the microscope […]