INDIAN SCHOOL AL WADI AL KABIR
DEPARTMENT OF SCIENCE 2014-15
CLASS VIII
WS NO.4
I.
DATE: 24-05-2014
TOPIC: THE MICROBIAL WORLD
NAME:
All the words given below are related to diseases. Try and use the word in a sentence in
the third column.
TERM
DEFINITION
WRITE A SENTENCE
USING THE WORD
CORRECTLY
Microbe
Pathogen
Antibiotics
Vector
Vaccine
II.
Given below are the names of some common diseases that occur in plants and animals.
Write the names/types of microbes that cause the respective diseases. Also mention
whether the disease affects plants or animals.
DISEASE
CAUSATIVE
PLANTS/ANIMALS
MICROBE
Tobacco Mosaic
Rusting of Wheat
Malaria
AIDS
Citrus Canker
Dengue
Tuberculosis
Foot and mouth disease
Hepatitis-A
Polio
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ACTIVITY NO – 2
1. Create microbial museum. Collect information and pictures on different types of
microbes, their structure and role in daily life. Assemble them in a picture file.
CRITERIA:
 PRESENTATION -2 MARKS, ORIGINALITY-2 MARKS, COLLECTION2MARKS,APPLICATION-2MARKS,PUNCTUALITY-2MARKS
I.
Answer the following questions in one word:
1.
2.
3.
4.
Give two examples of useful bacteria.
What is the name of the spherical shaped bacteria?
Which microorganism causes potato blight?
Name the method of food preservation which involves the use of heat to destroy
pathogens?
5. Name the disease caused by consuming contaminated food or drink.
6. What is the term given to chemicals that are used to check spoilage of food?
7. Nostoc and Anabaena are the examples of which type of algae?
8. What is the term used for ‘the process of breakdown of sugars by microorganisms to
produce carbon dioxide and acid or alcohol’?
9. What is the mode of reproduction in bacteria?
10. Name the bacteria that live in the intestine of human beings and other animals.
II.
Answer the following questions in one or two sentences:
1. Algae and fungi both are microbesa. Give two differences between them.
b. Identify the algae and fungus shown below-
c. An antibiotic is produced from the fungus pencilium. Name it.
d. Discuss the importance of antibiotics with suitable examples.
2. Name any two diseases caused by the bacteria and virus. What measures to be taken
to prevent these diseases?
3. The mosquitoes shown below are the carrier of diseases.
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ANOPHELES
AEDES
a. The culex mosquito carries filarial. What disease do the anopheles and the
aedes mosquito carry?
b. How can the spread of these diseases be prevented?
c. Differentiate between carriers and pathogens.
4. a. Identify the groups to which the following microbes belong.
b. Give an important characteristic of each.
III.
Answer the following in detail:
1. Explain the features and various shapes of bacteria.
2. Explain the usefulness of microorganisms in food industry.
3. What is vaccine? How does a vaccine work? Which child hood disease can be
prevented by vaccination?
4. How do microbes help in cleaning the environment?
5.
a. What are communicable diseases?
b. Identify which of the following are communicable diseases:
(cholera, chicken pox, malaria, diabetes, goiter).
c. how can we prevent the spread of communicable diseases?
6. Microorganisms are found even in places where no other life forms can exist.
What makes microorganisms so hardy?
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7. What is food poisoning? What are the symptoms of food poisoning? How can we
prevent food poisoning?
8. What is pasteurization? How is milk pasteurized?
9. What is food preservation? What are the common methods of preserving food at
our house?
10. a. Suggest any one preservation method for the following foodstuffs:
i.
Raw mangoes, ii. Fish, iii. Jellies, iv. Sauce
b. How does air tight packing help in preserving nuts and dry fruits?
IV.
Higher Order Thinking Skill (double matching)
Explanation
Microorganism group
Microorganism
1. Causes food
poisoning
a. Algae
i.
Yeast
2. Used in bakery and
preparing dishes
3. A source of protein
b. Bacteria
ii.
Chlorella
c. Fungi
iii.
Clostridium
4. Causes dysentery
d. Protozoa
iv.
Virus
5. Hepatitis disease
e. Viruses
v.
E. Histolytic
2. A water purifying device has a filter and a UV ray chamber through which the water
passes. What could be the purpose of this UV ray chamber?
3. A bucket containing mop water, with disinfectant added to it, was thrown in the lawn
to utilize the wastewater. After a few days it was seen that the patch of grass there
became yellow. Why?
4. Why are the grains dried in the sunshine?
Prepared by Ms. Ranjana S
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