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