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