Yeast is used for commercial use. Write one commercial use of yeast.

2

(a)

Name the process in yeast that converts sugars into alcohol.

2

(a)

Which pathogen causes anthrax?

2

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We are advised to avoid collection of water anywhere. Why?

2

(a)

Use a word for disease causing microorganisms

2

(a)

Vaccine is essential for what purpose? Mention two diseases for which vaccines are available.

2

(a)

An ingredient added to idlis and bhatura to make them soft. What is it?

2

(a)

Name any two algae which helps in nitrogen fixation.

2

(a)

We add a little curd to warm milk to set curd for the next day. Why?

2

(a)

How do some micro-organisms clean up the environment?

2

(a)

What are general preventive measures to protect ourselves from cholera?

2

(a)

Who discovered the first antibiotic? Name any two antibiotics.

2

(a)

Where do Rhizobium bacteria commonly live?

2

(a)

What do you mean by symbiotic relationship?

2

(a)

A boy opened two packets of milo drink. He left one in the refrigerator and another on the table. Three days later, he got a bad smell from the packet left on the table. The packet of milo drink in the refrigerator did not have a bad smell. Why? Explain.

2

(a)