Microbes In Human Wellfare

Question 1

Micro-organisms such as Lactobacillus and others commonly called …………..grow in milk and convert it to curd

Answer 1

lactic acid bacteria (LAB)

Question 2

Assertion:Conversion of milk to curd also helps in improving nutritional quality

Answer 2

Reason: It increases the vitamin B12

Question 3

In our stomach too, the LAB play very beneficial role in checking disease-causing microbes.

Answer 3

True

Question 4

Conversion of milk into curd is carried out by

Answer 4

Lactobacillus acidophilus

Question 5

Milk to yogurt conversion is carried out by

Answer 5

Lactobacillus bulgaricus

Question 6

Statement 1: The dough, which is used for making foods such as dosa and idli is fermented by yeast
Statement 2: The puffed-up appearance of dough is due to the production of CO2 gas.

Answer 6

Statement 1 is incorrect and 2 is correct

The fermentation takes place by the bacteria and not yeasts

Question 7

The dough, which is used for making bread, is fermented using……….

Answer 7

baker’s yeast (Saccharomyces cerevisiae)

Question 8

‘Toddy’, a traditional drink of some parts of southern India is made by fermenting sap from……….

Answer 8

palms

Question 9

Microbes are also used to ferment……./……./…….to make foods.

Answer 9

Fish
Soyabean
Bamboo-shoots

Question 10

……….. is one of the oldest food items in which microbes were used

Answer 10

Cheese

Question 11

The large holes in ‘Swiss cheese’ are due to production of a large amount of CO2 by a bacterium named………..

Answer 11

Propionibacterium sharmanii.

Question 12

Soyabean can be fermented to obtain
(3) items

Answer 12

Tofu
Tempe
Sufu

Question 13

Bacteria involved in fermentation for making idli and dosa are
List 2

Answer 13

Leuconostoc
Streptococcus

Question 14

Roquefort cheese is obtained with help of fermentation by

Answer 14

Penicillium roqueforti.

Question 15

Saccharomyces cerevisiae commonly called brewer’s yeast, is used for fermenting malted cereals and fruit juices, to produce……..

Answer 15

ethanol

Question 16

Depending on two factors different types of alcoholic drinks are obtained

Answer 16

Raw material used for fermentation
The type of processing (with or without distillation)

Question 17

Alcoholic drinks produced by distillation and without distillation

Answer 17

Distillation: Whiskey Brandy Rum
Non distillation: Wine Beer

Question 18

Antibiotics produced by microbes are regarded as one of the most significant discoveries of the…………. century and have greatly contributed towards the welfare of the human society.

Answer 18

twentieth

Question 19

………… was the first antibiotic to be discovered

Answer 19

Penicillin

Question 20

……………. while working on…………. bacteria, once observed a mould growing in one of his unwashed culture plates around which the bacteria could not grow.

Answer 20

Alexander Fleming

Staphylococci

Question 21

Penicillin was obtained from the mould………..

Answer 21

Penicillium notatum

Question 22

The full potential of penicillin as an effective antibiotic was established much later by……….. & ………….

Answer 22

Ernest Chain and Howard Florey

Question 23

Penicillin antibiotic was extensively used to treat American soldiers wounded in World War………

Answer 23

II

Question 24

Fleming, Chain and Florey were awarded the Nobel Prize in……… for this discovery.

Answer 24

1945

Question 25

Antibiotics have greatly improved our capacity to treat deadly diseases which used to kill millions all over the globe Name 4 in NCERT

Answer 25

Plague: Yersinia pestis (bacteria) Whooping cough (kali khansi): Bordetella pertussis (bacteria) Diphtheria (gal ghotu): Corynebacterium diphtheriae (bacteria) Leprosy (kusht rog): Mycobacterium leprae (bacteria)

Question 26

Name antibiotics which work by disrupting the cell wall synthesis (3)

Answer 26

Penicillin Bacteriacin Cephalosporin

Question 27

Name antibiotics that work by disrupting the plasmalemma repair (3)

Answer 27

Nystatin (anti fungal) Polymixinn Amphotrecin

Question 28

Erythromycin inhibits protein synthesis by

Answer 28

binding to the 23S ribosomal RNA molecule within the 50S ribosomal subunit, disrupting the transpeptidation/translocation step and 50S subunit assembly

Question 29

Name two antibiotics that work by disrupting the 30S ribosomes

Answer 29

Streptomycin Neomycin

Question 30

Tetracycline inhibits bacterial protein synthesis by

Answer 30

reversibly binding to the bacterial 30S ribosomal subunit, preventing the attachment of aminoacyl-tRNA to the A site,

Question 31

Chloramphenicol inhibits microbial protein synthesis by

Answer 31

binding to the 50 S subunit of the 70 S ribosome Thus inhibiting the action of peptidyl transferase and so preventing peptide bond formation

Question 32

Name organisms in NCERT and the products obtained from them

Answer 32

Aspergillus niger (a fungus) of citric acid Acetobacter aceti (a bacterium) of acetic acid Clostridium butylicum (a bacterium) of butyric acid Lactobacillus (a bacterium) of lactic acid

Question 33

Lipases are used in detergent formulations and are helpful in removing oily stains from the laundry These are obtained from

Answer 33

Candida Geotrichum

Question 34

Assertion: The bottled fruit juices bought from the market are clearer as compared to those made at home

Answer 34

Reason: The bottled juices are clarified by the use of pectinases and proteases

Question 35

Streptokinase produced by the bacterium…………. and modified by genetic engineering is used as a ‘clot buster’ for removing clots from the blood vessels of patients who have undergone myocardial infarction leading to heart attack.

Answer 35

Streptococcus

Question 36

A bioactive molecule, cyclosporin A, that is used as an immunosuppressive agent in organ-transplant patients, is produced by the fungus……………

Answer 36

Trichoderma polysporum

Question 37

Statins produced by the yeast …………….. have been commercialised as blood-cholesterol lowering agents

Answer 37

Monascus purpureus It acts by competitively inhibiting the enzyme responsible for synthesis of cholesterol.

Question 38

Amylases are obtained from (3) sources

Answer 38

Aspergilus Bacillus Rhizopus

Question 39

A major component of this waste water is………

Answer 39

human excreta.

Question 40

Statement 1: Treatment of waste water is done by the heterotrophic microbes naturally present in the sewage. Statement 2: This treatment is carried out in two stages

Answer 40

Both are correct

Question 41

Primary treatment involves physical removal of particles – large and small – from the sewage through……. & …………

Answer 41

filtration and sedimentation.

Question 42

The physical removal in primary treatment is done in stages Initial floating debris is removed by………… Then the grit (soil and small pebbles) are removed by……….

Answer 42

sequential filtration. sedimentation

Question 43

Statement 1: All solids that settle form the primary sludge, and the supernatant forms the effluent. Statement 2: The primary sludge from the primary settling tank is taken for secondary treatment.

Answer 43

Statement 1 is correct but 2 is incorrect The effluent from the primary settling tank is taken for secondary treatment.

Question 44

Secondary treatment is also called as………. Treatment

Answer 44

Biological treatment

Question 45

Assertion: Primary effluent is passed into large aeration tanks where it is constantly agitated mechanically and air is pumped into it.

Answer 45

Reason: This allows vigorous growth of useful aerobic microbes into flocs

Question 46

Define flocs

Answer 46

masses of bacteria associated with fungal filaments to form mesh like structures

Question 47

Assertion: The BOD (biochemical oxygen demand) of the effluent is reduced significantly

Answer 47

Reason: While growing, these microbes consume the major part of the organic matter in the effluent

Question 48

Define BOD

Answer 48

BOD refers to the amount of the oxygen that would be consumed if all the organic matter in one liter of water were oxidised by bacteria

Question 49

Assertion: BOD is an indirect measure of the organic matter present in the water

Answer 49

Reason: The BOD test measures the rate of uptake of oxygen by micro-organisms in a sample of water

Question 50

The greater the BOD of waste water, lesser is its polluting potential.

Answer 50

False The greater the BOD of waste water, more is its polluting potential.

Question 51

Once the BOD of sewage or waste water is reduced significantly, the effluent is then passed into a settling tank where the…….. are allowed to sediment

Answer 51

bacterial ‘flocs’ This sediment is called activated sludge.

Question 52

Statement 1: The remaining major part of the sludge is pumped into large tanks called anaerobic sludge digesters. Statement 2: Here, other kinds of bacteria, which grow anaerobically, digest the bacteria and the fungi in the sludge

Answer 52

Both are correct

Question 53

During digestion in sludge digesters bacteria produce a mixture of gases such as (3) in NCERT

Answer 53

Methane Hydrogen sulphide Carbon dioxide

Question 54

The Ministry of Environment and Forests has initiated…………. &……………. to save these major rivers of our country from pollution

Answer 54

Ganga Action Plan and Yamuna Action Plan Under these plans, it is proposed to build a large number of sewage treatment plants so that only treated sewage may be discharged in the rivers

Question 55

Biogas is a mixture of gases containing predominantly…….

Answer 55

methane

Question 56

The type of the gas produced depends upon (2) factors

Answer 56

Microbes used Organic substrates they utilise.

Question 57

Statement 1: Bacteria which grow aerobically on cellulosic material, produce large amount of methane along with CO2 and H2. Statement 2: These bacteria are collectively called methanogens, and one such common bacterium is Methanobacterium

Answer 57

Statement 1 is incorrect and 2 is correct Bacteria which grow anaerobically on cellulosic material, produce large amount of methane along with CO2 and H2.

Question 58

The biogas plant consists of a concrete tank ……….. feet deep in which bio-wastes are collected and a slurry of dung is fed. A

Answer 58

10-15 feet deep

Question 59

A floating cover is placed over the slurry, which keeps on rising as the gas is produced in the tank due to the microbial activity

Answer 59

True

Question 60

The technology of biogas production was developed in India mainly due to the efforts of two different organisations

Answer 60

Indian Agricultural Research Institute (IARI) Khadi and Village Industries Commission (KVIC).

Question 61

…………… refers to the use of biological methods for controlling plant diseases and pests

Answer 61

Biocontrol

Question 62

Assertion: A key belief of the organic farmer is that biodiversity furthers health

Answer 62

Reason: The more variety a landscape has, the more sustainable it is

Question 63

Assertion: The organic farmer holds the view that the eradication of the creatures that are often described as pests is not only possible, but also undesirable.

Answer 63

Reason: Without them the beneficial predatory and parasitic insects which depend upon them as food or hosts would not be able to survive

Question 64

Ladybird (beetle with red and black markings) and Dragonflies are useful to get rid of

Answer 64

aphids and mosquitoes, respectively

Question 65

In order to control butterfly caterpillars the bacteria Bacillus thuringiensis (often written as Bt) is used

Answer 65

True

Question 66

These (Bt) are available in sachets as dried spores which are mixed with water and sprayed onto vulnerable plants such as………&………where these are eaten by the insect larvae.

Answer 66

brassicas and fruit trees

Question 67

A biological control being developed for use in the treatment of plant disease is the fungus………….

Answer 67

Trichoderma free-living fungi that are very common in the root ecosystems They are effective biocontrol agents of several plant pathogens.

Question 68

Baculoviruses are pathogens that attack……… and other………

Answer 68

insects arthropods

Question 69

The majority of baculoviruses used as biological control agents are in the genus………….

Answer 69

Nucleopolyhedrovirus

Question 70

Nucleopolyhedroviruses are excellent candidates for species-specific………… spectrum insecticidal applications.

Answer 70

narrow

Question 71

Nucleopolyhedrovirus have no negative impacts on plants, mammals, birds, fish or even on non-target insects

Answer 71

True

Question 72

…………….. are organisms that enrich the nutrient quality of the soil

Answer 72

Biofertilisers

Question 73

The main sources of biofertilisers are (3) in ncert line

Answer 73

Bacteria Fungi Cyanobacteria

Question 74

In leguminous plants the symbiotic association of…………. helps in fixing nitrogen

Answer 74

Rhizobium

Question 75

IPM stands for

Answer 75

Integrated Pest Management

Question 76

Free living Nitrogen fixing organisms

Answer 76

Azospirillum Azotobacter

Question 77

Many members of the genus………. form mycorrhiza

Answer 77

Glomus

Question 78

The fungal symbiont in these associations absorbs…………… from soil and passes it to the plant

Answer 78

phosphorus

Question 79

Plants having mycorrhiza associations show other benefits also, such as (3) in NCERT

Answer 79

Resistance to root-borne pathogens Tolerance to salinity and drought Overall increase in plant growth and development

Question 80

In………… fields, cyanobacteria serve as an important biofertiliser

Answer 80

paddy

Question 81

During growth, the LAB produce acids that coagulate and completely digest the milk proteins True or false

Answer 81

False partially digest the milk proteins