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