Ncert – class 8- science – Chapter 2: Microorganisms: Friend and Foe 1 Welcome to your Ncert - class 8- science - Chapter 2: Microorganisms: Friend and Foe 1 1. What is the term for the activity occurring when yeast is grown in a sugar solution? Fermentation Distillation Evaporation Decomposition None 2. Which of the following serves as an indirect source of nitrogen in the soil? All of these Dead remains of plants Human faeces Animal droppings None 3. Anil and Sangeeta wanted to do research on which type of preservation is best and effective. Choose the improper combination from below? Anil tried Preservation by Common Salt and Sangeeta tried Preservation by chemical method Anil tried Preservation by Heat and Cold Treatments and Sangeeta tried preservation by sodium benzene Anil tried Preservation by Oil and Vinegar and Sangeeta tried Preservation by edible oils Anil tried Preservation by Sugar and Sangeeta tried Preservation by Storage and Packing None 4. Pathogens are microorganisms which Help us in digesting our food Cause diseases in living organisms Transmit the disease-causing microbes Spoil clothing and leather None 5. Which of the following are examples of preservatives? Jams and pickles edible Oils and coconut oils All of the above Salt and sugar None 6. Which of the following plant diseases is transmitted by seeds? Yellow vein mosaic of Okra Citrus canker All of the above Rust of wheat None 7. Against which disease are children protected under Pulse Polio Program? Tuberculosis Measles Hepatitis Polio None 8. Which bacterium does not fix nitrogen? Rhizobium Nitrosomonas Clostridium Azotobacter None 9. What among the following is used as fertiliser when bacteria decompose sewage? Solid waste Soluble substances Sludge Carbon dioxide None 10. Ravi consumed some roadside food along with his friends. He had a severe stomach ache and loose motions on reaching home. What is he suffering from? Dysentery Food poisoning Fever Dehydration None 11. A patient is suffering from a severe bacterial infection. The best treatment for curing this infection would be the use of: Antibiotic Antibody Water Vaccine None 12. How do herbivores get nitrogen for their body needs? They take the rainwater containing dissolved nitrogen compounds They are able to fix atmospheric nitrogen directly They obtain usable compounds of nitrogen from soil They feed on plants and obtain nitrogen compounds from them. None 13. Name the group of microorganisms in which Oscillatoria, Anabaena and Nostoc belong which fix atmospheric nitrogen and improve soil fertility. Blue green algae Fungi Free-living bacteria Symbiotic bacteria None 14. Antibiotics are used to treat infections in Humans Animals All of these Plants None 15. Which of the following is not a way of transmission of pathogens? Vaccinating an individual When bitten by a carrier Direct contact with an infected person Consuming contaminated food or water None 16. Select the correct combinations based on the application of microorganisms. , Column A Column B i. Brewing a. Microbial decomposition of wastes ii. Antibiotics b. Prevention of cholera, TB and hepatitis iii. Vaccines c. Alcohol and wine i) – c), ii) – b, iii) – d), iv) – a) i) – d) , ii) – c) iii)-a), iv) - b i) – b), ii) – a), iii)- d) iv) – c) i) – c), ii) – d), iii) – a), iv) – b) None 17. Identify the ammonifying bacteria. Bacillus ramosus Clostridium Nitrosomonas Nitrobacter None 18. Where is the Rhizobium bacteria found in leguminous plants Stem Flowers Root Leaves None 19. What will happen if we do not preserve food properly? Food will not change its colour or look. Food will become spoilt due to growth of microbes Food will give good odour even after long time Food will remain fresh for long time None 20. Which option is true for antibiotics? They are produced from bacteria and fungi. medicines that kill or stop the growth of the disease-causing microorganisms. It is mixed with the feed of livestock and poultry to check microbial infection in animals. Are used to cure a variety of diseases. None Time's up Please Share This Share this content Opens in a new window Opens in a new window Opens in a new window Opens in a new window Opens in a new window Opens in a new window Opens in a new window Opens in a new window Opens in a new window Opens in a new window Leave a Reply Cancel replyCommentEnter your name or username to comment Enter your email address to comment Enter your website URL (optional) Save my name, email, and website in this browser for the next time I comment.
