Microbes In Human Welfare

Biology
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The prickly pear weed (Opuntia) became a menace and it has been successfully controlled by

A
DDT spray
B
Cattle
C
Destroying its seeds
D
Cochineal insects
Hard
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A legume having symbiotic association with two nitrogen fixing bacteria (Rhizobium and Aerospirillum) is

A
Crotalaria juncea
B
Sesbania aculeata
C
Sesbania rostrata
D
Cyamopsis tetragonoloba
Hard
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Third generation pesticides are ?

A
Insect repellents
B
Pheromones
C
Pathogens
D
Insect (juvenile) hormone analogues
Hard
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Farmers have reported 50% higher yield of rice by using which bio-fertilizer?

A
Azolla pinnata
B
Legume - Rhizobium symbiosis
C
Cyanobacteria
D
Mycorrhiza
Hard
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If wheat field is inoculated with Rhizobium, then

A
Soil will become nitrogen rich
B
No effect on soil nitrogen
C
Soil will be depleted of nitrogen
D
Soil will become rich in calcium
Hard
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Which one of the following, proved effective for biological control of nematode diseases in plants?

A
Gliocladium virens
B
Paecilomyces lilacinus
C
Pisolithus tinctorius
D
Pseudomonas cepacia
Hard
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Green manuring enhances crop yield by

A
5 - 10%
B
15 - 25%
C
30 - 50%
D
60 - 70%
Hard
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Biofertilizers include

A
Cowdung manure and farmyard waste
B
A quick growing crop ploughed back
C
BGA/Anabaena azollae
D
All of the above
Hard
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Which disease is caused in children due to excessive use of nitrate fertilizers?

A
Septicemia
B
Jaundice
C
Methaemoglobinaemia
D
Mumps
Hard
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What is required for nitrogen fixation by Rhizobium?

A
Potassium
B
Phosphorus
C
Molybdate
D
Sodium
Hard
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