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