Class XII · Biology practice
Microbes in Human Welfare MCQs
Check your understanding, bookmark questions and revisit your mistakes.
455 questions in this collection · Page 28 of 46
Question 271 of 455
📘 CLASS XII
Microbes In Human Welfare
A small part of the activated sludge is pumped back into the aeration tank to serve as the _____.
A small part of the activated sludge is pumped back into the aeration tank to serve as the inoculum.
Question 272 of 455
📘 CLASS XII
Microbes In Human Welfare
The remaining major part of the activated sludge is pumped into large tanks called _____.
The remaining major part of the sludge is pumped into large tanks called anaerobic sludge digesters.
Question 273 of 455
📘 CLASS XII
Microbes In Human Welfare
During anaerobic digestion of sludge, bacteria produce a mixture of gases including methane, carbon dioxide, and _____.
Bacteria produce a mixture of gases such as methane, hydrogen sulphide and carbon dioxide.
Question 274 of 455
📘 CLASS XII
Microbes In Human Welfare
The mixture of gases produced during anaerobic digestion, which is inflammable and used as fuel, is called _____.
These gases form biogas and can be used as source of energy as it is inflammable.
Question 275 of 455
📘 CLASS XII
Microbes In Human Welfare
The microbial treatment of sewage methodology has been practiced for more than a _____ now.
This methodology has been practiced for more than a century now.
Question 276 of 455
📘 CLASS XII
Microbes In Human Welfare
The Ministry of Environment and Forests initiated the Ganga Action Plan and _____ to save major rivers from pollution.
The Ministry of Environment and Forests has initiated Ganga Action Plan and Yamuna Action Plan.
Question 277 of 455
📘 CLASS XII
Microbes In Human Welfare
Biogas is a mixture of gases containing predominantly _____.
Biogas is a mixture of gases (containing predominantly methane).
Question 278 of 455
📘 CLASS XII
Microbes In Human Welfare
Chemical insecticides and pesticides are toxic and harmful, polluting the soil, groundwater, fruits, vegetables, and _____.
These chemicals have been polluting our environment (soil, ground water), fruits, vegetables and crop plants.
Question 279 of 455
📘 CLASS XII
Microbes In Human Welfare
A key belief of the organic farmer is that _____ furthers health and sustainability.
A key belief of the organic farmer is that biodiversity furthers health.
Question 280 of 455
📘 CLASS XII
Microbes In Human Welfare
The organic farmer aims to keep pests at _____ levels rather than eradicating them completely.
The insects are kept at manageable levels by a complex system of checks and balances.
Page score: 0/40