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. 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) – d) , ii) – c) iii)-a), iv) - b i) – c), ii) – d), iii) – a), iv) – b) i) – b), ii) – a), iii)- d) iv) – c) None 2. Antibiotics are used to treat infections in Plants Animals Humans All of these None 3. 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 4. 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 5. 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 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 Anil tried Preservation by Common Salt and Sangeeta tried Preservation by chemical method None 6. Where is the Rhizobium bacteria found in leguminous plants Stem Flowers Leaves Root None 7. Against which disease are children protected under Pulse Polio Program? Hepatitis Measles Polio Tuberculosis None 8. What will happen if we do not preserve food properly? Food will give good odour even after long time Food will remain fresh for long time Food will not change its colour or look. Food will become spoilt due to growth of microbes None 9. 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 10. How do herbivores get nitrogen for their body needs? They are able to fix atmospheric nitrogen directly They take the rainwater containing dissolved nitrogen compounds They obtain usable compounds of nitrogen from soil They feed on plants and obtain nitrogen compounds from them. None 11. Pathogens are microorganisms which Cause diseases in living organisms Transmit the disease-causing microbes Spoil clothing and leather Help us in digesting our food None 12. Which of the following is not a way of transmission of pathogens? When bitten by a carrier Vaccinating an individual Consuming contaminated food or water Direct contact with an infected person None 13. What is the term for the activity occurring when yeast is grown in a sugar solution? Distillation Fermentation Evaporation Decomposition None 14. Which of the following are examples of preservatives? edible Oils and coconut oils Salt and sugar Jams and pickles All of the above None 15. What among the following is used as fertiliser when bacteria decompose sewage? Solid waste Carbon dioxide Soluble substances Sludge None 16. Identify the ammonifying bacteria. Nitrobacter Nitrosomonas Bacillus ramosus Clostridium None 17. Name the group of microorganisms in which Oscillatoria, Anabaena and Nostoc belong which fix atmospheric nitrogen and improve soil fertility. Symbiotic bacteria Free-living bacteria Fungi Blue green algae None 18. 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 19. Which of the following plant diseases is transmitted by seeds? All of the above Rust of wheat Yellow vein mosaic of Okra Citrus canker None 20. Which bacterium does not fix nitrogen? Azotobacter Clostridium Rhizobium Nitrosomonas 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.
