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