Microbes in human welfare .

Microbes making food for us :

Microbes are organisms not visible to naked eyes. Microbes can be useful as well as harmful. They can be bacteria , fungi viruses or protists .

1. Microbes like bacteria have been used since ages for making curd. Curd is formed when milk is mixed with lactobacillus bacteria this result in production of lactic acid from lactose sugar which causes denaturation of milk proteins at acidic pH . Lactobacillus require slightly higher temperature than the room temperature for its activity. At lower temperature it becomes inactive . Curd formation increases the vitamin B12 amount which is good for our health and it also check the growth of pathogenic bacteria in our gut.

(Yeast )

Yeast is a fungus which release enzymes for action on substrate .Its substrate is basically carbohydrates like sugar . On fermentation yeast produces ethanol and carbon dioxide from sugar.Bread require dough of wheat or maida which is also acted upon by yeast to produce carbon dioxide which cause holes in dough this making light puffy bread . Different types of fermented beverages are available like beer wine gin vodka whisky some of may contain less ethanol concentration or more ethanol concentration. Further distillation of alcohol obtained from yeast action will result in increase in alcoholic concentration. For yeast it is difficult to survive at higher alcoholic concentration.Wine and beer are made without distillation so they contain less ethanol . Whisky , brandy ,rum has more ethanol due to distillation process. 

Cheese is also formed by action of bacteria or yeast on milk . Swiss cheese is made by mixing milk with Propionibacterium sharmanii. Large amount of carbon dioxide causes large holes in swiss cheese. Roqueforti cheese is formed by action of penicillium roqueforti fungi .

Antibiotics and microbes 

Antibiotics are chemical secreted by one type of organisms against another type of organism. The antibiotics can inhibit or kill the microbes. First antibiotic was  penicillin which was invented by Alexander Fleming during his research on Staphylococcus bacteria . Penicillium inhibited growth of bacteria in petridish in lab . Later Fleming , Florey and Chain received Nobel prize for large scale production of this antibiotic . Some of the disease against which it worked were urinary tract infection , wound infection . 

CH 10 -   MICROBES IN HUMAN WELFARE

Question 1

A symbiotic relationship/interaction in which 'one species benefits and the other species is not affected' is called:

A	Ectomycorrhizae
B	Endomycorrhizae
C	Commensalism
D	Helotism

 

Question 2

Agriculture by using only biofertilizers is called

A	Manuring
B	Composting
C	Inorganic farming
D	Organic farming

 

Question 3

Bacterial leaf blight of rice is caused by a species of:

A	Envinia
B	Xanthomonas
C	Pseudomonas
D	Alternaria

 

Question 4

Cyanobacteria serves as important biofertilizers in the fields of

A	Rice
B	Maize
C	Wheat
D	Sugar cane

 

Question 5

Ethanol is commercially produced through a particular species of

A	Aspergillus
B	Saccharomyces
C	Clostridium
D	Trichoderma

 

Question 6

Human insulin is being commercially produced from a transgenic species of

A	Saccharomyces
B	Escherichia
C	Mycobacterium
D	Rhizobium

 

Question 7

Which one of the following is not used in organic farming?

A	Snail
B	Glomus
C	Earthworm
D	Oscillatoria

 

Question 8

One of the free-living anaerobic nitrogen-fixer is

A	Azotobacter
B	Beijerinckia
C	Rhodospirillum)
D	Rhizobium

 

Question 9

Organism like Escherichia coli and Chlamydia trachomatis fall into which domain?

A	Eukarya
B	Archaea
C	Bacteria
D	Animalia

 

Question 10

Organisms called Methanogens are most abundant in a

A	Hot spring
B	Sulphur rock
C	Cattle yard
D	Polluted stream

 

Question 11

Physical removal of large and small from the sewage through filtration and sedimentation is called:

A	Primary treatment
B	Secondary treatment
C	Tertiary treatment
D	Quaternary treatment

 

Question 12

Secondary sewage treatment is mainly a

A	Biological process
B	Physical process
C	Mechanical process
D	Chemical process

 

Question 13

Select the correct statement from the following

A	Activated sludge-sediment in settlement tanks of sewage treatment plant is a rich source of aerobic bacteria.
B	Biogas is produced by the activity of aerobic bacteria on animal waste
C	Methanobacterium is an aerobic bacterium found in rumen of cattle
D	Biogas, commonly called gobar gas, is pure methane

 

Question 14

Semiconservative replication of DNA was first demonstrated in

A	Salmonella typhimurium
B	Drosophila melanogaster
C	Escherichia coli
D	Streptococcus pneumoniae

 

Question 15

Some hyperthermophilic organisms that grow in highly acidic (pH2) habitats belong to the two groups

A	Liverworts and yeasts
B	Eubacteria and archaea
C	Cyanobacteria and diatoms
D	Protists and mosses

 

Question 16

The common nitrogen-fixer in paddy fields is

A	Frankia
B	Rhizobium
C	Azospirillum
D	Oscillatoria

 

Question 17

The most common fungal partners of mycorrhiza are ______ species.

A	Azotobacter
B	Glomus
C	Azolla
D	Frankia

 

Question 18

The most important of the symbiotic nitrogen fixing bacteria which forms nodules on the roots of legume plants is

A	Aspergillus
B	Rhizobium
C	Penicillium
D	Streptococcus

 

Question 19

The symbiotic association of fungi with the roots of higher plants is called:

A	Eubacteria
B	Actinomycetes
C	Mycorrhiza
D	None of these

 

Question 20

The term antibiotic was coined by:

A	Howard Florey
B	John Tyndall
C	Selman Waksman
D	Gerhard Domagk

 

Question 21

The yeast that is used in alcohol production and bread making is

A	Escherichia coli
B	Saccharomyces cerevisiae
C	Bacillus subtilis
D	Pseudomonas putida

 

Question 22

What is the common name of Drosophila melanogaster?

A	Fruit fly
B	Roundworm
C	Zebrafish
D	Chlamydia

 

Question 23

Which of the following bacterium produces butyric acid?

A	Acetobacter aceti
B	Clostridium butylicum
C	Lactobacillus
D	None of these

 

Question 24

Which of the following is a gram-negative bacterium?

A	Escherichia coli
B	Bacillus subtilis
C	Streptomyces coelicolor
D	Amycolatopsis orientalis

 

Question 25

Which of the following is a symbiotic nitrogen fixer?

A	Azolla
B	Glomus
C	Azotobacter
D	Frankia

 

Question 26

Which of the following is added to milk to curdle it or produce fermented milk products?

A	Azotobacter
B	Lactobacillus
C	Rhizobium
D	Clostridium

 

Question 27

Which of the following will begin fixing nitrogen only after they stop reproducing?

A	Penicillium
B	Rhizobium
C	Aspergillus
D	Streptococcus

 

Question 28

Which of the followings is also called sac fungi that live parasitically and in various habitats?

A	Basidiomycetes
B	Zygomycetes
C	Ascomycetes
D	Oomycetes

 

Question 29

Which of the followings is mainly produced by the activity of anaerobic bacteria on sewage?

A	Marsh gas
B	Laughing gas
C	Propane
D	Mustard gas

 

Question 30

Which one of the following is a wrong matching of a microbe and its industrial product, while the remaining three are correct?

A	Clostridium butylicum - lactic acid
B	Aspergillus niger - citric acid
C	Yeast - statins
D	Acetobacter aceti - acetic acid
Question 31

A nitrogen fixing microbe associated with Azolla in rice fields is

A	Frankia
B	Tolypothrix
C	Spirulina
D	Anabaena

 

Question 32

Which one of the following microbes forms symbiotic association with plants and helps them in their nutrition?

A	Glomus
B	Trichoderma
C	Azotobacter
D	Aspergillus

 

Question 33

A patient brought to a hospital with myocardial infarction is normally immediately given

A	Cyclosporin–A
B	Statins
C	Penicillin
D	Streptokinase

 

Question 34

The most abundant prokaryotes helpful to humans in making curd from milk and in production of antibiotics are the ones categorized as

A	Chemosynthetic autotrophs
B	Heterotrophic bacteria
C	Cyanobacteria
D	Archaebacteria

 

Question 35

Monascus purpureus is a yeast used commercially in the production of

A	Citric acid
B	Blood cholesterol lowering statins
C	Ethanol
D	Streptokinase for removing clots from the blood vessels

 

Question 36

Two microbes found to be very useful in genetic engineering are

A	Diplococcus sp. and Pseudomonas sp.
B	Vibrio cholerae and a tailed bacteriophage
C	Escherichia coli and Agrobacterium tumefaciens
D	Crown gall bacterium and Caenorhabditis elegans

 

Question 37

Which one of the following plant is commonly used as green manure?

A	Cassia fistula
B	Acacia nilotica
C	Dalbergia sissoo
D	Crotalaria juncea

 

Question 38

Rotenone is

A	A bioherbicide
B	A natural insecticide
C	An insect hormone
D	A natural herbicide

 

Question 39

The biological control of agricultural pests, unlike chemical control is

A	Very expensive
B	Polluting
C	Self perpetuating
D	Toxic

 

Question 40

Azolla is used as a biofertilizer because it

A	Has association of nitrogen fixing Cyanobacteria
B	Has association of nitrogen fixing Rhizobium
C	Multiplies very fast to produce massive biomass
D	Has association of mycorrhiza

 

Question 41

Green manure plants used by farmer mainly belong to

A	Solanaceae
B	Leguminosae
C	Compositae
D	Poaceae

 

Question 42

Yeast is used in the production of

A	Bread and beer
B	Cheese and butter
C	Citric acid and lactic acid
D	Lipase and pectinase

 

Question 43

Which of the following microbes is used for commercial production of ethanol?

A	Trichoderma polysporum
B	Streptococcus
C	Clostridium butylicum
D	Saccharomyces cerevisiae

 

Question 44

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

A	Primary treatment
B	Activated sludge treatment
C	Cyclic treatment
D	Tertiary treatment

 

Question 45

Crop rotation is used by farmers to increase

A	Organic content of soil
B	Nitrogenous content of soil
C	Soil fertility
D	All of these
Question 46

Which one of the following is used as biological insecticide?

A	Silkmoth
B	Caterpillar
C	Tiger beetle
D	Mazra Poka

 

Question 47

In paddy fields biological nitrogen fixation is chiefly brought by

A	Mycorrhiza
B	Green algae
C	Cyanobacteria
D	Rhizobium

 

Question 48

During anaerobic digestion of organic waste, such as in producing biogas, which one of the following is left undergraded?

A	Hemi-cellulose
B	Lignin
C	Lipids
D	Cellulose

 

Question 49

An important drug is obtained from the bark of

A	Withania
B	Cinchona
C	Papaver
D	Momordica

 

Question 50

Bacillus thuringiensis (Bt) strains have been used for designing novel

A	Biofertilizers
B	Bio-mineralization processes
C	Bio-insecticidal plants
D	Bio-metallurgical techniques

 

Question 51

Powdery mildew of wheat is caused by a species of

A	Ustilago
B	Erysiphe
C	Puccinia
D	Albugo

 

Question 52

Genetic diversity in agricultural crops is threatened by:

A	Introduction of high yielding varieties
B	Intensive use of fertilizers
C	Extensive intercropping
D	Intensive use of biopesticides

 

Question 53

Which of the following is not used as a biopesticide?

A	Trichoderma harzianum
B	Bacillus thuringiensis
C	Xanthomonas campestris
D	Nuclear Polyhedrosis Virus (NPV)

 

Question 54

Which of the following is wrongly matched?

A	Aloe – Medicine
B	Petunia – Fumigatory
C	Sesbania – Fodder
D	Asparagus – Vegetable

 

Question 55

A hybrid where the cytoplasm of two parent cells are fused by retaining only one parental nucleus is called

A	Asymmetric somatic hybrid
B	Symmetric somatic hybrid
C	An interbreed
D	Cybrid

 

Question 56

Pollution from animal excreta and organic waste from kitchen can be most profitably minimized by

A	Storing them in underground storage tanks
B	Using them for producing biogas.
C	Vermiculture
D	Using them directly as biofertilizers.

 

Question 57

Morphine, which is used as an analgesic is obtained from

A	Taxus brevifolia
B	Papaver somniferum
C	Cinchona officinalis
D	Berberis nilghiriensis

 

Question 58

Study the followings related to uses of plants and identify the correct match for the sorghum and cotton respectively.

I. Blood purification and organic fertilizer.

II. Animal f5eed and paper industry

III. 'B' Vitamin and cosmetics.

IV. Explosives and organic fertilizer.

The correct pair is:

A	I, II
B	II, III
C	III, IV
D	II, IV

 

Question 59

Match Column I with II and choose the right option.

Column – I			Column - II
(1)		Artemisia	(A)	Fibre
(2)		Astragalus	(B)	Insecticide
(3)		Phormium	(C)	Rat poison
(4)		Chrysanthemum	(D)	Medicine
(5)		Withania	(E)	Vermifuge
			(F)	Gum
A	1 – D, 2 – C, 3 – F, 4 – B, 5 – 3
B	1 – B, 2 – E, 3 – D, 4 – C, 5 – A
C	1 – E, 2 – E, 3 – A, 4 – F, 5 – D
D	1 – E, 2 – F, 3 – A, 4 – B, 5 – D

 

Question 60

Study the following lists:

List - I		List - II
(A)	Usage of bisexual flowers as female parents	(I)	Clonal selection
(B)	Incorporation of several desirable characters into a single variety	(II)	Pure line selection
(C)	Exploiting hybrid vigour for many generations	(III)	Emasculation
(D)	Improving local varieties of self pollinated crop	(IV)	Hybridization
		(V)	Polyploidy breeding

The correct match is:

A	A - IV, B - V, C - III, D - I
B	A - II, B - III, C - IV, D - V
C	A - III, B - IV, C - I, D – II
D	A - I, B - V, C - II, D - IV

61. Gobar is rich in                  

62. Streptokinase used as clot buster is obtained from                   

63.                    serves as an important biofertilizer in paddy field.

64. Microbe used in control of oil spills.

65. Streptomycin is prepared from                         (

66. Alcoholic drink produced without distillation                     

67. The free living fungus trichoderma can be used for                    

68. The vitamin whose content increases while milk converts to curd

69. Smallest living cell that can live without oxygen

70 All viruses are                   

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

ANSWERS

 

1.C      2.D      3.B      4.A      5.B      6.B      7.A      8.C      9.C      10.C    11.A    12.A    13.A

14.C    15.B    16.C    17.B    18.B    19.C    20.C    21.B    22.A    23.B    24.A    25.D    26.B

27.B    28.C    29.A    30.A    31.D    32.A    33.A    34.B    35.B    36.C    37.D    38.B    39.C   

40.B    41.B    42.A    43.D    44.B    45.C    46.C    47.C    48.B    49.B    50.C    51.B    52.A

53.C    54.B    55.D    56.B    57.B    58.D    59.D    60.C

61. Methano bacterium 62. Strepto cocci. 63 Cyanobacteria 64.Pseudomonas putida 65.Streptomyces griseus. 66. Wine. 67. Biological control of plant diseases.68. Vit.B12

69. Mycoplasma. 70.Parasitic