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 Both A and B Bacteria and fungi None of the above None 2. The chemicals that are used to control weeds are called ______. Pesticides Fertilisers Weedicides Manures None 3. Which of the following should be avoided to be safe from communicable diseases? consume uncovered item of food. Use mosquito net and repellents. use handkerchief on the nose and mouth while sneezing. Do not let water collect anywhere, in coolers, tyres, flower pot etc None 4. Which bacterium has symbiotic relationship with leguminous plants? Bifidobacterium Staphylococcus Helicobacter pylori 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? All the above statements are correct Lighting does not fix the nitrogen present in the soil. When plants die bacteria and fungi present in the soil convert the nitrogenous wastes into nitrogenous compounds to be used by plants again. Some animals eat plants, in this way nitrogen from plant goes into animal body. None 6. Which of the following statements is/are true? 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. The atmospheric nitrogen cannot be taken directly by plants and animals. None 7. Fungi degrade organic waste compounds into simple substances, ready for reuse by plants. Here fungi act as? Reproducers None of the above Degrader Decomposer None 8. Which of the following microbes helps in curdling of milk? Rhizopus Aspergillus Saccharomyces Lactobacillus None 9. Yeast produces CO2 and Ethanol during the process of ________. Digestion Fermentation Excretion Transpiration None 10. Medicines used to kill or stop the growth of the disease-causing microorganisms are called _______ Antibiotic Antiseptic Antidote Anti-Allergic None 11. Which of the following acts as a carrier for the parasite of Malaria? Aedes Mosquito Beatles Housefly Anopheles Mosquito None 12. 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 13. In the process of pasteurization, after milk is heated, what we must do? Rapidly cool it None of the above We should add penicillin to it Both A and B None 14. 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 Blue green algae Diatoms None 15. Which of the following is the use of microorganism? Fermentation Antibiotics All of the above Nitrogen fixation None 16. Which of the following microorganisms do not reproduce outside the cells? Protozoa Bacterium Fungi Virus None 17. Which of the following activities is of friendly microorganisms? Decomposition of inorganic wastes preparation of curd, breads, cakes, medicines, etc. None of the above Both A and B None 18. Which of the following microbes is responsible for causing Citrus Canker disease? Yeast Bacteria Fungi Virus None 19. The following options are inventor with corresponding inventions, which of the following are incorrect? Alexander Fleming – penicillin Edward Jenner - the vaccine for smallpox. Louis Pasteur – fertilization none of the above None 20. The living organism which cannot be seen with our naked eyes alone is known as? Unicellular Microorganisms Microbes Both Microorganisms and 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 comment Enter your email address to comment Enter your website URL (optional) Save my name, email, and website in this browser for the next time I comment.
