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