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. Medicines used to kill or stop the growth of the disease-causing microorganisms are called _______ Antidote Antiseptic Anti-Allergic Antibiotic None 2. The chemicals that are used to control weeds are called ______. Manures Weedicides Fertilisers Pesticides None 3. Fungi degrade organic waste compounds into simple substances, ready for reuse by plants. Here fungi act as? Degrader None of the above Reproducers Decomposer None 4. Which of the following microbes is responsible for causing Citrus Canker disease? Virus Fungi Yeast Bacteria None 5. Which of the following activities is of friendly microorganisms? None of the above preparation of curd, breads, cakes, medicines, etc. Decomposition of inorganic wastes Both A and B None 6. Microorganisms in the soil convert atmospheric nitrogen into ammonium compounds, thereby enabling the survival of; Both A and B None of the above Plants and animals Bacteria and fungi None 7. Which of the following acts as a carrier for the parasite of Malaria? Beatles Anopheles Mosquito Housefly Aedes Mosquito None 8. Which of the following microbes helps in curdling of milk? Aspergillus Lactobacillus Saccharomyces Rhizopus None 9. Which of the following microorganisms do not reproduce outside the cells? Fungi Bacterium Protozoa Virus None 10. 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 11. Which of the following statements is/are true? 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. The atmospheric nitrogen cannot be taken directly by plants and animals. Our atmosphere has 78% nitrogen gas. None 12. Which of the following statements is true? Edward Jenner discovered the vaccine for smallpox in 1798. Malaria is transmitted by female Aedes mosquito Antibiotics were discovered by Pasteur in 1857 Dengue fever is caused by Dengue Virus transmitted by female Anopheles mosquito None 13. Which of the following is the use of microorganism? Fermentation All of the above Nitrogen fixation Antibiotics None 14. The following options are inventor with corresponding inventions, which of the following are incorrect? none of the above Louis Pasteur – fertilization Alexander Fleming – penicillin Edward Jenner - the vaccine for smallpox. None 15. Which bacterium has symbiotic relationship with leguminous plants? Helicobacter pylori Bifidobacterium Staphylococcus None of the above None 16. In the process of pasteurization, after milk is heated, what we must do? Both A and B Rapidly cool it None of the above We should add penicillin to it None 17. Which of the following should be avoided to be safe from communicable diseases? 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. consume uncovered item of food. None 18. 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: Prions Chlamydomonas Blue green algae Diatoms None 19. The living organism which cannot be seen with our naked eyes alone is known as? Unicellular Microbes Both Microorganisms and Microbes Microorganisms None 20. Yeast produces CO2 and Ethanol during the process of ________. Digestion Excretion Fermentation Transpiration 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.
