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