Welcome to the Living World: March 2021

2.   Swiss cheese has large holes due to the production of CO2 by …………………
3.   The chemical substances produced by some microbes and can kill the pathogens are known as …………….
4.   Note the relationship between first two words and fill up the fourth place.

Saccharomyces cerevisiae: Ethanol
Clostridium butylicum: …………….

5. Name 2 enzymes used to clarify bottled juices.
6. Cyclosporin A is produced by................

a. Aspergillus niger
b. Clostridium tetani
c. Trichoderma polysporum
d. Acetobacter aceti

7. Penicillin is the first antibiotic discovered by …………….
8. The main ingredient of Biogas is

a. Ethane
b. Hydrogen sulphide
c. Methane
d. Carbon dioxide

9. Select a bio-control agent from the given microbe.

a. Trichoderma
b. Rhinovirus
c. Saccharomyces
d. Streptococcus

10. The nitrogen fixing symbiotic bacteria in root nodules of leguminous plants is

a. Azotobacter
b. Azospirillum
c. Clostridium
d. Rhizobium

2 Score Questions

11. Lactic acid bacteria are beneficial microbe for our health. Justify this statement pointing two examples.
12. Match the column B & C with respect to A.

A	B	C
Cyanobacteria	Biocontrol	Antibiotic
Baculoviruses	Penicillin	Biofertilizer
Penicillium notatum	Anabaena	IPM programme

13. Complete the table given below:

Bioactive molecule	Source	Medical importance
a	Streptococcus	Removes clots from blood vessels
Cyclosporine-A	b	c
d	Monascus purpureus	Blood cholesterol lowering agent

14. Many microbes are acid producers. Name any two such microbes and acids produced by them.

15. “BOD is an index of water pollution”

a. Do you agree with this statement? Justify.
b. Expand BOD.

16. BOD of some water sample is given below.

Sample 1: 200mg/L
Sample 2: 80mg/L
Sample 3: 300mg/L
Sample 4: 25mg/L

a. Which of above water sample is most polluted?
b. What is meant by flocs? Mention its role in sewage treatment.

17.   Expand: (a) IARI (b) KVIC.
18.   Microbes can be considered as a source of energy. Substantiate with an example.
19.   Match the following:

Methanogens	Aspergillus niger
Flocs	Aerobic microbes
Citric acid	Anaerobic microbes
Baker’s yeast	Lactobacillus
	Saccharomyces cerevisiae

20. (a) What are the advantages of biofertilizers over chemical fertilizers?
(b) Give two examples for biofertilizer.

ANSWERS

1.   (b) Lactobacillus
2.   Propionibacterium sharmani.
3.   Antibiotics
4.   Butyric acid
5.   Pectinases & Proteases.
6.   (c) Trichoderma polysporum
7.   Alexander Fleming
8.   (c) Methane
9.   (a) Trichoderma
10.   (d) Rhizobium
11.   Lactic acid bacteria (LAB) increase vitamin B12 in curd. Also, it helps to check pathogens in stomach.

12.

A	B	C
Cyanobacteria	Anabaena	Biofertilizer
Baculoviruses	Biocontrol	IPM programme
Penicillium notatum	Penicillin	Antibiotic

13.

a. Streptokinase
b. Trichoderma polysporum
c. Immunosuppressive agent
d. Statins

14.   Aspergillus niger (a fungus) : Citric acid.
      Acetobacter aceti (a bacterium) : Acetic acid.

15.

a. Yes. It is a measure of organic matter present in the water. Greater BOD means water is more polluted.
b. Biochemical Oxygen Demand.

16.

a. Sample 3.
b. Flocs are aerobic bacteria associated with fungal filaments to form mesh-like structures. They consume the organic matter in the effluent reducing its BOD.

17.

a) Indian Agricultural Research Institute.
b) Khadi and Village Industries Commission.

18. This statement is true. Because microbes such as Methanogens can be used to produce biogas. Biogas is an important energy source.

19.

Methanogens	Anaerobic microbes
Flocs	Aerobic microbes
Citric acid	Aspergillus niger
Baker’s yeast	Saccharomyces cerevisiae

20. (a) Chemical fertilizers are harmful to the soil and beneficial organisms. Biofertilizers have no such problems. They can maintain the nature and quality of soil.
(b) Rhizobium, Mycorrhiza.