Class XII · Biology practice
Microbes in Human Welfare MCQs
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455 questions in this collection · Page 6 of 46
Question 51 of 455
📘 CLASS XII
Microbes In Human Welfare
Examples of free-living bacteria that fix atmospheric nitrogen in the soil, enriching its nitrogen content, include:
Other bacteria can fix atmospheric nitrogen while free-living in the soil (examples Azospirillum and Azotobacter).
Question 52 of 455
📘 CLASS XII
Microbes In Human Welfare
The symbiotic association formed between fungi and plants is known as:
Fungi are also known to form symbiotic associations with plants (mycorrhiza).
Question 53 of 455
📘 CLASS XII
Microbes In Human Welfare
Many members of the genus *Glomus* form which type of association?
Many members of the genus Glomus form mycorrhiza.
Question 54 of 455
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Microbes In Human Welfare
Plants having mycorrhizal associations derive benefits such as resistance to root-borne pathogens and tolerance to:
Plants having such associations show benefits such as resistance to root-borne pathogens, tolerance to salinity and drought.
Question 55 of 455
📘 CLASS XII
Microbes In Human Welfare
Cyanobacteria are autotrophic microbes that are widely distributed in aquatic and terrestrial environments and many can fix:
Cyanobacteria are autotrophic microbes... many of which can fix atmospheric nitrogen.
Question 56 of 455
📘 CLASS XII
Microbes In Human Welfare
Examples of cyanobacteria that function as important biofertilisers, especially in paddy fields, include:
e.g. Anabaena, Nostoc, Oscillatoria, etc. In paddy fields, cyanobacteria serve as an important biofertiliser.
Question 57 of 455
📘 CLASS XII
Microbes In Human Welfare
Besides N2 fixation, Blue green algae (Cyanobacteria) also contribute to soil fertility by adding:
Blue green algae also add organic matter to the soil and increase its fertility.
Question 58 of 455
📘 CLASS XII
Microbes In Human Welfare
What essential component is added to milk by LAB that helps in the coagulation and partial digestion of milk proteins?
During growth, the LAB produce acids that coagulate and partially digest the milk proteins.
Question 59 of 455
📘 CLASS XII
Microbes In Human Welfare
A small amount of curd added to fresh milk to initiate curd formation is known as:
A small amount of curd added to the fresh milk as inoculum or starter contain millions of LAB.
Question 60 of 455
📘 CLASS XII
Microbes In Human Welfare
Which disease mentioned in the text used to be treated extensively with Penicillin, especially for wounded soldiers during World War II?
This antibiotic [Penicillin] was extensively used to treat American soldiers wounded in World War II.
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