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