Why is Rhizobium categorised as a 'symbiotic bacterium'? How does it act as a biofertiliser?

2

(a)

Name the GM bacterium whose product is used as a clot buster. Name the product.Specify its used in medical science.

2

(a)

How do methanoges help in producing biogas?

2

(a)

Name the blank spaces a,b,c and d given in the following table:

Type of Microbe	Name	Commercial Product
Bacterium Fungus    c Fungus	a     b Monascus purpureus Penicillium notatum	Lactic acid Cyclosporin A Stain        d

2

(a)

How do mycorrhizal fungi help the plants harbouring them?

2

(a)

Why are cyanobacteria considered useful in paddy fields?

2

(a)

What is brewing?

2

(a)

List three examples of antibiotics that are industrially viable. Give their source.

2

(a)

Name the microorganisms associated in the manufacture of (1) Vinegar (2) Alcohol (3) Tetracycline (4) Citric acid.

2

(a)

Water samples, three in number namely river water; sewage water and secondary effluent from STP were subjected to BOD test. They were labeled A B & C but the laboratory technician did not note which was which. The BOD values of three samples A, B & C were recorded as 30mg/l, 8mg/l and 500mg/l respectively. Which sample of water is most polluted? Can you assign the correct label to each assuming the river water relatively clear?

2

(a)

Prabha has seen huge garbage dumps outside your school which are not being regularly disposed of by MCD / Nagar Parishad. Prabha discusses the problems with school mates and decide to organize rally to spread awareness among local people about public hygiene.
A. Prepare two slogans for rally
B. Name any two infectious diseases which may spread due to such unhygienic conditionsat public place

2

(a)

Genes encoding resistance to antibiotics like Ampicillin, chloramphenicol, tetracycline are useful selectable markers for E.coli. The normal E.coli cells do not carry resistance against any of these antibiotics. Ankita wants to know more clarity on these scriptures. She asks doubts to her teacher. Based on this please answer the following.
a) Name the best known plasmid vector?
b) What are selectable markers?
c) On what basis Biology teacher advices Ankita.

2

(a)

How do biofertilisers enrich the fertility of the soil?

2

(a)

Milk starts to coagulate when Lactic acid bacteria(LAB) is added to milk as a starter. Mention two benefits which LAB provides.

2

(a)

What are the advantages of biogas plant in rural.

2

(a)