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. Which of the following is not a way of transmission of pathogens? Direct contact with an infected person Consuming contaminated food or water When bitten by a carrier Vaccinating an individual None 2. What is the term for the activity occurring when yeast is grown in a sugar solution? Decomposition Distillation Evaporation Fermentation None 3. Which of the following serves as an indirect source of nitrogen in the soil? Dead remains of plants Human faeces All of these Animal droppings None 4. What will happen if we do not preserve food properly? 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 Food will not change its colour or look. None 5. Name the group of microorganisms in which Oscillatoria, Anabaena and Nostoc belong which fix atmospheric nitrogen and improve soil fertility. Fungi Symbiotic bacteria Free-living bacteria Blue green algae None 6. Antibiotics are used to treat infections in All of these Humans Plants Animals None 7. Pathogens are microorganisms which Spoil clothing and leather Help us in digesting our food Transmit the disease-causing microbes Cause diseases in living organisms None 8. Where is the Rhizobium bacteria found in leguminous plants Leaves Flowers Root Stem None 9. Which of the following plant diseases is transmitted by seeds? Yellow vein mosaic of Okra Rust of wheat Citrus canker All of the above None 10. Which of the following are examples of preservatives? edible Oils and coconut oils Salt and sugar Jams and pickles All of the above None 11. A patient is suffering from a severe bacterial infection. The best treatment for curing this infection would be the use of: Water Antibody Vaccine Antibiotic None 12. How do herbivores get nitrogen for their body needs? They obtain usable compounds of nitrogen from soil They feed on plants and obtain nitrogen compounds from them. They are able to fix atmospheric nitrogen directly They take the rainwater containing dissolved nitrogen compounds None 13. Which option is true for antibiotics? 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. They are produced from bacteria and fungi. None 14. 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? Food poisoning Dehydration Fever Dysentery None 15. What among the following is used as fertiliser when bacteria decompose sewage? Solid waste Sludge Soluble substances Carbon dioxide None 16. Identify the ammonifying bacteria. Clostridium Bacillus ramosus Nitrobacter Nitrosomonas None 17. Against which disease are children protected under Pulse Polio Program? Polio Hepatitis Tuberculosis Measles None 18. 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 Sugar and Sangeeta tried Preservation by Storage and Packing 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 None 19. Which bacterium does not fix nitrogen? Nitrosomonas Azotobacter Rhizobium Clostridium None 20. 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) – c), ii) – d), iii) – a), iv) – b) i) – d) , ii) – c) iii)-a), iv) - b i) – c), ii) – b, iii) – d), iv) – a) i) – b), ii) – a), iii)- d) iv) – c) 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.
