Ncert – class 8- science – Chapter 2: Microorganisms: Friend and Foe 2 Welcome to your Ncert - class 8- science - Chapter 2: Microorganisms: Friend and Foe 2 1. Which bacterium has symbiotic relationship with leguminous plants? Bifidobacterium None of the above Staphylococcus Helicobacter pylori None 2. Which of the following should be avoided to be safe from communicable diseases? use handkerchief on the nose and mouth while sneezing. Use mosquito net and repellents. Do not let water collect anywhere, in coolers, tyres, flower pot etc consume uncovered item of food. None 3. Which of the following microbes is responsible for causing Citrus Canker disease? Yeast Bacteria Virus Fungi None 4. Which of the following statements is/are true? The atmospheric nitrogen cannot be taken directly by plants and animals. Blue green algae present in the air fix nitrogen from the atmosphere and convert into compounds of nitrogen. After nitrogen fixation, Nitrogen is used for the synthesis of plant proteins and other compounds. Our atmosphere has 78% nitrogen gas. None 5. Fungi degrade organic waste compounds into simple substances, ready for reuse by plants. Here fungi act as? Reproducers Degrader Decomposer None of the above None 6. The living organism which cannot be seen with our naked eyes alone is known as? Unicellular Microorganisms Microbes Both Microorganisms and Microbes None 7. Which of the following microorganisms do not reproduce outside the cells? Protozoa Virus Fungi Bacterium None 8. Yeast produces CO2 and Ethanol during the process of ________. Excretion Fermentation Transpiration Digestion None 9. Which of the following microbes helps in curdling of milk? Rhizopus Aspergillus Lactobacillus Saccharomyces None 10. In the process of pasteurization, after milk is heated, what we must do? None of the above Both A and B Rapidly cool it We should add penicillin to it None 11. The chemicals that are used to control weeds are called ______. Fertilisers Weedicides Pesticides Manures None 12. Which of the following is the use of microorganism? All of the above Fermentation Antibiotics Nitrogen fixation None 13. Algae have unique features, which differentiate it from the rest of the microorganisms. Like, it is either unicellular or multicellular, it is autotrophic or heterotrophic. A unicellular algae having a glass like cell wall is: Diatoms Chlamydomonas Prions Blue green algae None 14. Medicines used to kill or stop the growth of the disease-causing microorganisms are called _______ Antibiotic Anti-Allergic Antiseptic Antidote None 15. Microorganisms in the soil convert atmospheric nitrogen into ammonium compounds, thereby enabling the survival of; Plants and animals Bacteria and fungi Both A and B None of the above None 16. Paheli studied about nitrogen cycle, she wrote all the processes in points. Below are few of the point Paheli wrote. Which of the process she wrote is wrong? When plants die bacteria and fungi present in the soil convert the nitrogenous wastes into nitrogenous compounds to be used by plants again. All the above statements are correct Some animals eat plants, in this way nitrogen from plant goes into animal body. Lighting does not fix the nitrogen present in the soil. None 17. Which of the following statements is true? Antibiotics were discovered by Pasteur in 1857 Malaria is transmitted by female Aedes mosquito Dengue fever is caused by Dengue Virus transmitted by female Anopheles mosquito Edward Jenner discovered the vaccine for smallpox in 1798. None 18. Which of the following acts as a carrier for the parasite of Malaria? Aedes Mosquito Housefly Beatles Anopheles Mosquito None 19. Which of the following activities is of friendly microorganisms? preparation of curd, breads, cakes, medicines, etc. None of the above Both A and B Decomposition of inorganic wastes None 20. The following options are inventor with corresponding inventions, which of the following are incorrect? Edward Jenner - the vaccine for smallpox. none of the above Alexander Fleming – penicillin Louis Pasteur – fertilization 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.
