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प्रश्न
Give reasons.
A refrigerator is used in almost every home.
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उत्तर
A refrigerator is used in almost every home because it prevents the spoilage of food. Refrigerator provides an optimum environment for storage of vegetables, fruits, and cooked and uncooked food. If an optimum temperature is not provided, it can lead to the growth of bacteria and fungi, thus leading to spoilage of food.
संबंधित प्रश्न
Alcohol is produced with the help of _________.
Match the organisms in Column A with their action in Column B.
| A | B | ||
| (i) | Bacteria | (a) | Fixing Nitrogen |
| (ii) | Rhizobium | (b) | Setting of curd |
| (iii) | Lactobacillus | (c) | Baking of bread |
| (iv) | Yeast | (d) | Causing Malaria |
| (v) | A protozoan | (e) | Causing Cholera |
| (vi) | A Virus | (f) | Causing AIDS |
| (g) | Producing antibodies |
Can microorganisms be seen with the naked eye? If not, how can they be seen?
State whether the following statement is true or false. Explain your statement.
Tomato wilt is a viral disease.
Draw a neat and labelled diagram.
Bacteriophage.
What are the main features of a microorganism?
How disease causing microorganisms enter into human beings?
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 |
‘Cry’ protein is produced by the bacteria ______.
Assertion: Bacillus Thuringiensis is a biocontrol agent.
Reason: It produces a protein called ‘cry protein’ which kills insect larva.
