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