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