Yeast is used in the production of

1

(a)

sugar

(b)

alcohol

(c)

hydrochloric acid

(d)

oxygen

The following is an antibiotic

1

(a)

sodium bicarbonate

(b)

streptomycin

(c)

alcohol

(d)

yeast

Carrier of malaria-causing protozoan is

1

(a)

female Anopheles mosquito

(b)

cockroach

(c)

housefly

(d)

butterfly

The most common carrier of communicable diseases is

1

(a)

ant

(b)

housefly

(c)

dragonfly

(d)

spider

The bread or idli dough rises because of

1

(a)

heat

(b)

grinding

(c)

growth of yeast cells

(d)

kneading

Typhoid is a ________ disease.

1

(a)

protozoan

(b)

viral

(c)

bacterial

(d)

fungi

This bacterium promotes the formation of milk into curd:

1

(a)

rhizobium

(b)

lactobacillus

(c)

aedes

(d)

all

This micro-organism is used for the large-scale production of alcohol, wine and acetic acid:

1

(a)

amoeba

(b)

paramecium

(c)

chlamydomonas

(d)

yeast

Edward Jenner discovered:

1

(a)

fermentation

(b)

antibiotics

(c)

vaccine

(d)

none of these

Nitrogen fixation is brought about by :

1

(a)

blue-green algae

(b)

bacteria

(c)

both (a) and (b)

(d)

none of these

Under unfavourable conditions, microorganisms form a _______________ around themselves.

1

(a)

cyst

Pathogens are___________ causing organisms.

1

(a)

disease

______________ is a nitrogen fixing bacteria.

1

(a)

Rhizobium

Paramecium is a slipper- shaped ___________________

1

(a)

Protozoa

Carriers of specific microorganisms are called ___________________

1

(a)

vectors

Edward Jenner discovered the process of fermentation.

1

(a) True

(b) False

Foot and mouth disease is a bacterial disease in animals.

1

(a) True

(b) False

Microorganisms can be found only in air and water.

1

(a) True

(b) False

Protozoa cause diseases like dysentery and malaria.

1

(a) False

(b) True

Jams, jellies and squashes are preserved by adding salt.

1

(a) True

(b) False

Mention a characteristic of viruses

2

(a)

Write the name of two groups of microorganisms which live in colonies.

2

(a)

Name the process in yeast that converts sugars into alcohol.

2

(a)

How are micro-organisms useful for commercial productions?

2

(a)

Who discovered the first antibiotic? Name any two antibiotics.

2

(a)

Name the microorganisms which can fix atmospheric nitrogen in the soil.

3

(a)

Write a short paragraph on the harmful effects of microorganisms.

3

(a)

Who discovered the bacterium Bacillus anthracis? Which disease can be caused by it? Is it harmful?

3

(a)

Give causative microorganism, mode of transmission and one preventive measure Qf human diseases like Polio, Cholera and Hepatitis-B.

3

(a)

What are food preservatives? Explain some common food preservatives.

3

(a)