MICROORGANISMS : FRIEND AND FOE

Vaccine ?

write a Brief note on Bacteria.

what is Beneficial use of yeast.

what is Medicinal use of microorganisms.

Use of microorganisms in increasing soil fertility.

Use of microorganisms in cleaning the environment

Method of food preservation using - Pasteurization .

Method of food preservation using - Oil and vinegar

Method of food preservation using - Common salt

what is Food poisoning ?

what is Nitrogen cycle.

Disease causing microorganisms in plants

How can we prevent the following diseases?
(a) Cholera
(b) Typhoid
(c) Hepatitis A

Give reasons for the following.
(a) Fresh milk is boiled before consumption while processed milk stored in packets can be consumed without boiling.
(b) Raw vegetables and fruits are kept in refrigerators whereas jams and pickles can be kept outside.
(c) Farmers prefer to grow beans and peas in nitrogen deficient soils.
(d) Mosquitoes can be controlled by preventing stagnation of water though they do not live in water. Why?

How do vaccines work?

(a) Name two diseases that are caused by virus.
(b) Write one important characteristic of virus.

What will happen to ‘pooris’ and ‘unused kneaded flour’ if they
are left in the open for a day or two?

While returning from the school, Boojho ate chaat from a street
hawker. When he reached home, he felt ill and complained of
stomach ache and fell ill. What could be the reason?

Classify the following into friendly and harmful microorganisms.
Yeast, malarial parasite, Lactobacillus, bread mould, Rhizobium,
Bacillus anthracis
Friendly Harmful
________ ________
________ ________
________ ________
________ ________

Match the microorganisms given in the Column A to the group
to which they belong in Column B.
Column A                                        Column B
(a) Lactobacillus                               (i) Algae
(b) Aspergillus                                  (ii) Protozoa
(c) Spirogyra                                    (iii) Fungi
(d) Paramecium                                  (iv) Bacteria

Paheli watched her grandmother making mango pickle. After
she bottled the pickle, her grand mother poured oil on top of the
pickle before closing the lid. Paheli wanted to know why oil was
poured? Can you help her understand why?

Polio drops are not given to children suffering from diarrhoea.
Why?

Why should we avoid standing close to a tuberculosis patient
while he/she is coughing?

In the soil, which nutrient is enriched by blue-green algae
(cyanobacteria)?

Name the process in yeast that converts sugars into alcohol.

Name one commercial use of yeast.

Match the names of scientists given in Column A with the
discovery made by them given in Column B.
Column A                                                         Column B
(a) Louis Pasteur                                              (i) Penicillin
(b) Robert Koch                                               (ii) anthrax bacterium
(c) Edward Jenner                                            (iii) Fermentation
(d) Alexander Fleming                                       (iv) small pox vaccine
                                                                       (v) Typhoid

Suggest a suitable word for each of the following statements.
(a) Chemicals added to food to prevent growth of microorganisms.
(b) Nitrogen-fixing microorganism present in the root nodules
of legumes.
(c) Agent which spreads pathogens from one place to another.
(d) Chemicals which kill or stop the growth of pathogens.

Unscramble the jumbled words underlined in the following
statements.
(a) Cells of our body produce santiidobe to fight pathogens.
(b) curbossulite is an air-borne disease caused by a bacterium.
(c) Xanrhat is a dangerous bacterial disease.
(d) Yeasts are used in the wine industry because of their property
of meronettinaf.

:  

What are antibiotics? What precautions must be taken while taking antibiotics?

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

Tick the correct answer:

(a) Yeast is used in the production of

(i) sugar (ii) alcohol

(iii) hydrochloric acid (iv) oxygen

(b) The following is an antibiotic

(i) Sodium bicarbonate (ii) Streptomycin

(iii) Alcohol (iv) Yeast

(c) Carrier of malaria-causing protozoan is

(i) female Anopheles mosquito (ii) cockroach

(iii) housefly (iv) butterfly

(d) The most common carrier of communicable diseases is

(i) ant (ii) housefly

(iii) dragonfly (iv) spider

(e) The bread or idli dough rises because of

(i) heat (ii) grinding

(iii) growth of yeast cells (iv) kneading

(f) The process of conversion of sugar into alcohol is called

(i) nitrogen fixation (ii) moulding

(iii) fermentation (iv) infection

What are antibiotics? What precautions must be taken while taking antibiotics?

 Write a short paragraph on the harms caused by microorganisms.

Write 10 lines on the usefulness of microorganisms in our lives.

What are the major groups of microorganisms?

Can microorganisms be seen with the naked eye? If not, how can they be seen?

Match the organisms in Column I with their action in Column II.

Fill in the blanks:
(a) Microorganisms can be seen with the help of a _________.
(b) Blue green algae fix _________ directly from air to enhance fertility of soil.
(c) Alcohol is produced with the help of _________.
(d) Cholera is caused by _________.