7. MICROBES IN HUMAN WELFARE
2020
SAY
1. A free living
nitrogen fixing bacteria in the soil. (1)
(a)
Rhizobium (b) Azospirillum
(c)
Nostoc (d) Anabaena
ü Answer:
(b) Azospirillum
2. Match the
following: (2)
|
(a)
Acetic acid (b)
Citric acid (c)
Cyclosporine
A (d)
Lactic acid |
(i) Trichoderma
polysporum (ii) Acetobacter aceti (iii) Lactobacillus (iv) Aspergillus niger (v) Monascus purpureus |
ü Answer:
|
(a)
Acetic acid (b)
Citric acid (c)
Cyclosporine A (d)
Lactic acid |
(ii) Acetobacter
aceti (iv) Aspergillus niger (i) Trichoderma
polysporum (iii) Lactobacillus |
2020
MARCH
1.
Microbe which
helps in the production of Biogas. (1)
a.
Aspergillus
niger
b.
Trichoderma
polysporum
c.
Saccharomvces
cerevisiae
d.
Methanobacterium
ü Answer:
(d) Methanobacterium
2. Some examples
of microbes in human welfare are given. Classify them under the headings given
below. (2)
[Rhizobium, Propionibacterium sharmanii, Azaspirillum,
Lactic acid bacteria, Anabaena, Azotobacter, Aspergillus niger, Saccharomyces
cerevisiae]
|
Microbes in
Household Products |
Microbes as
Bio-fertilizers |
|
|
|
ü Answer:
|
Microbes
in Household Products |
Microbes
as Bio-fertilizers |
|
Propionibacterium sharmanii Lactic acid bacteria Saccharomyces cerevisiae Aspergillus niger |
Rhizobium Azospirillum Azotobacter Anabaena |
2019
SAY June
1. Match the
following: (2)
|
A |
B |
|
(a)
Citric Acid (b)
Acetic acid (c)
Lactic acid (d)
Butyric acid |
I.
Acetobactor aceti Il.
Clostridium butylicum III.
Aspergillus niger IV.
Lactobacillus V.
Trichoderma polysporum VI.
Saccharomyces cerevisiae |
ü Answer:
|
A |
B |
|
(a) Citric Acid (b) Acetic acid (c) Lactic acid (d) Butyric acid |
III. Aspergillus niger I. Acetobactor aceti IV. Lactobacillus Il. Clostridium butylicum |
2. Bio-fertilisers
are organisms that enrich the nutrient quality of the' soil. How these bio-
fertilisers enrich the soil nutrients? Give two examples. (2)
ü Answer:
They can fix nitrogen from the atmosphere. Also
absorb phosphorous. E.g. Rhizobium, Cyanobacteria, Mycorrhiza etc.
2019
MARCH
1. Microbes are
useful to human beings in diverse ways. If so, name the following. (2)
a.
Microbe known
as "Baker's Yeast".
b.
Lactic acid
producing bacterium.
c.
Fungus which
helps in the production of bio-active molecule - cyclosporine A.
d.
Symbiotic
nitrogen fixing bacterium.
ü Answer:
a.
Saccharomyces
cerevisiae.
b.
Lactobacillus.
c.
Trichoderma
polysporum.
d.
Rhizobium.
2018
SAY
1. In sewage
treatment plants microbes play a significant role. Distinguish between primary
and secondary treatment in sewage plants. (2)
ü Answer:
Primary treatment: It is the physical removal of material in sewage by
sequential filtration and sedimentation.
Secondary treatment: It involves aeration and constant agitation of
effluent that causes vigorous growth of aerobic bacteria. They consume organic
matter in the effluent and reduces its BOD.
2018
MARCH
1. Complete the
table with appropriate terms: (2)
|
Organism |
Scientific name |
Bioactive product |
|
Fungus |
……..A……. |
Citric acid |
|
…..B….. |
Acetobacter aceti |
Acetic acid |
|
Fungus |
Trichoderma polysporum |
……C……. |
|
Yeast |
……..D…….. |
stain |
ü Answer:
A=
Aspergillus niger.
B=
Bacterium
C= Cyclosporine A
D= Saccharomyces cerevisiae.