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