NCERT - Microbes in Human Welfare Questions and Answers of Class 12 Biology | GkSeries

Questions
31 Semiconservative replication of DNA was first demonstrated in
1 Salmonella typhimurium
2 Drosophila melanogaster
3 Escherichia coli
4 Streptococcus pneumoniae

Answer: Escherichia coli
32 A sewage treatment process in which a part of decomposer bacteria present in the wastes is recycled into the starting of the process is called
1 Primary treatment
2 Activated sludg0e treatment
3 Cyclic treatment
4 Tertiary treatment

Answer: Activated sludg0e treatment
Advertisement
Article and Schedule Quiz Start Test!

DOWNLOAD CURRENT AFFAIRS PDF FROM APP

33 The symbiotic association of fungi with the roots of higher plants is called:
1 Eubacteria
2 Actinomycetes
3 Mycorrhiza
4 None of these

Answer: Mycorrhiza
34 Monascus purpureus is a yeast used commercially in the production of
1 Citric acid
2 Blood cholesterol lowering statins
3 Ethanol
4 Streptokinase for removing clots from the blood vessels

Answer: Blood cholesterol lowering statins
35 Bacterial leaf blight of rice is caused by a species of:
1 Envinia
2 Pseudomonas
3 Alternaria
4 Xanthomonas

Answer: Xanthomonas
36 A symbiotic relationship/interaction in which 'one species benefits and the other species is not affected' is called:
1 Ectomycorrhizae
2 Endomycorrhizae
3 Commensalism
4 Helotism

Answer: Commensalism
37 Powdery mildew of wheat is caused by a species of
1 Ustilago
2 Erysiphe
3 Puccinia
4 Albugo

Answer: Erysiphe
38 Which of the following is added to milk to curdle it or produce fermented milk products?
1 Azotobacter
2 Lactobacillus
3 Rhizobium
4 Clostridium

Answer: Lactobacillus
39 Crop rotation is used by farmers to increase
1 Organic content of soil
2 Nitrogenous content of soil
3 Soil fertility
4 All of these

Answer: Soil fertility
40 Agriculture by using only biofertilizers is called
1 Manuring
2 Composting
3 Inorganic farming
4 Organic farming

Answer: Organic farming
41 Which of the followings is also called sac fungi that live parasitically and in various habitats?
1 Basidiomycetes
2 Zygomycetes
3 Ascomycetes
4 Basidiomycetes

Answer: Ascomycetes
42 Two microbes found to be very useful in genetic engineering are
1 Diplococcus sp. and Pseudomonas sp.
2 Vibrio cholerae and a tailed bacteriophage
3 Escherichia coli and Agrobacterium tumefaciens
4 Crown gall bacterium and Caenorhabditis elegans

Answer: Escherichia coli and Agrobacterium tumefaciens
43 The most important of the symbiotic nitrogen fixing bacteria which forms nodules on the roots of legume plants is
1 Aspergillus
2 Rhizobium
3 Penicillium
4 Streptococcus

Answer: Rhizobium
44 Some hyperthermophilic organisms that grow in highly acidic (pH2) habitats belong to the two groups
1 Liverworts and yeasts
2 Eubacteria and archaea
3 Cyanobacteria and diatoms
4 Protists and mosses

Answer: Eubacteria and archaea
45 One of the free-living anaerobic nitrogen-fixer is
1 Azotobacter
2 Beijerinckia
3 Rhodospirillum
4 Rhizobium

Answer: Rhodospirillum

ADRE 2.0 FULL LENGTH MOCK TEST

Take Mock Tests

Missiles Mock Test Start Test!
SSC MTS Mock Test Start Test
IBPS CLERK MOCK TEST Start Test
SSC MTS 2022 JULY 26 Shift 1 (ENGLISH) Start Test!
SSC GD Previous Year Paper 2021 Nov 17 Shift - I (Hindi) Start Test!
SSC CGL Tier - 1 PYP 2022 April 21 Shift- 1 (ENGLISH) Start Test!
MPSC PAPER I MOCK TEST 1 (ENGLISH) Start Test!
IB Security Assistant Mock test 1 (english) Start Test!
UP POLICE CONSTABLE MOCK TEST 1 Start Test!
DELHI POLICE CONSTABLE MOCK TEST 1 (HINDI) Start Test!

Chapters

Advertisement
Assam Direct Recruitment Test Series