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