{"id":12910,"date":"2020-10-09T18:24:49","date_gmt":"2020-10-09T12:54:49","guid":{"rendered":"https:\/\/mcq-questions.com\/?p=12910"},"modified":"2022-03-02T11:33:26","modified_gmt":"2022-03-02T06:03:26","slug":"microorganisms-friend-and-foe-class-8-extra-questions","status":"publish","type":"post","link":"https:\/\/mcq-questions.com\/microorganisms-friend-and-foe-class-8-extra-questions\/","title":{"rendered":"Microorganisms: Friend and Foe Class 8 Extra Questions and Answers Science Chapter 2"},"content":{"rendered":"

Microorganisms: Friend and Foe Class 8 Extra Questions and Answers Science Chapter 2 PDF are solved by experts and will guide students in the right direction. Students can get how to tackle different questions easily by solving the Extra Questions for Class 8 Science<\/a> Question bank on a regular basis.<\/p>\n

Class 8 Science Chapter 2 Extra Questions and Answers Microorganisms: Friend and Foe<\/h2>\n

Extra Questions for Class 8 Science Chapter 2 Microorganisms: Friend and Foe with Answers<\/strong><\/p>\n

Microorganisms: Friend and Foe Class 8 Extra Questions Very Short Answer Type<\/h3>\n

Question 1.
\nWrite the agent that is responsible for the spread of following diseases:
\nPolio =________
\nTuberculosis = _________
\nAnswer:
\nPolio = Viruses
\nTuberculosis = Bacteria<\/p>\n

\"Microorganisms:<\/p>\n

Question 2.
\nWrite the name of bacteria which converts milk into curd.
\nAnswer:
\nLactobacillus<\/p>\n

Question 3.
\nName two diseases caused by protozoans.
\nAnswer:
\nDiseases like dysentery and malaria are caused by protozoans.<\/p>\n

Question 4.
\nName two diseases caused by bacteria.
\nAnswer:
\nTyphoid and tuberculosis (T.B.).<\/p>\n

Question 5.
\nWhere are microbes found?
\nAnswer:<\/p>\n

    \n
  1. They are present everywhere because they can survive under all types of environments.<\/li>\n
  2. They are also found inside human body.<\/li>\n<\/ol>\n

    Question 6.
    \nWhat are the commercial uses of yeast?
    \nAnswer:
    \nYeast is used for commercial production of alcohol and wine.<\/p>\n

    Question 7.
    \nName the process of conversion of sugar into alcohol.
    \nAnswer:
    \nFermentation.<\/p>\n

    Question 8.
    \nWho discovered the process of fermentation?
    \nAnswer:
    \nLouis Pasteur in 1857.<\/p>\n

    \"Microorganisms:<\/p>\n

    Question 9.
    \nWho discovered Penicillin?
    \nAnswer:
    \nAlexander Fleming discovered the antibiotic called Penicillin in 1929.<\/p>\n

    Question 10.
    \nName some of the diseases that can be prevented by vaccination.
    \nAnswer:
    \nCholera, tuberculosis, smallpox, hepatitis, etc.<\/p>\n

    Question 11.
    \nWho discovered the vaccine for smallpox?
    \nAnswer:
    \nEdward Jenner discovered the vaccine for smallpox in 1798.<\/p>\n

    Question 12.
    \nCan you name some diseases for which you have been given injection in your childhood to protect you from them?
    \nAnswer:
    \nThey are diphtheria, tuberculosis, chiekenpox, cholera, etc.<\/p>\n

    Question 13.
    \nWhat is the most prominent role of microorganisms in pollution control?
    \nAnswer:
    \nThey degrade the harmful substances and thereby play prominent role in pollution control.<\/p>\n

    Microorganisms: Friend and Foe Class 8 Extra Questions Short Answer Type 1<\/h3>\n

    Question 1.
    \nDefine microorganisms with two examples.
    \nAnswer:
    \nA microorganism is a living thing that is too small that it can\u2019t be seen with the naked eye. Microorganisms can be found in air, water and in the bodies of plants and animals. They may be unicellular or multicellular.<\/p>\n

    For Example:
    \nBacteria: Lactobacillus
    \nProtozoa: Amoeba, Paramecium<\/p>\n

    \"Microorganisms:<\/p>\n

    Question 2.
    \nHow do microorganisms help to improve the fertility of soil?
    \nAnswer:
    \nRhizobium bacteria present in the nodules of the roots of leguminous plants helps in the replenishment of the soil with nitrogen. Rhizobium bacteria takes nitrogen from the atmosphere and fix it directly into nitrogenous compounds and increase the fertility of the soil.<\/p>\n

    Question 3.
    \nSeema took 50 gm of flour (atta) and added some sugar and mixed it with warm water\u201eand also added small amount of yeast powder into it:
    \nWrite the observation noted by her after two hours.
    \nWhat is the function of yeast in this activity?<\/p>\n

    Answer:
    \n(i) After two hours the flour (atta) is found to be raised a little bit.
    \n(ii) Yeast reproduces rapidly and produces carbon dioxide during respiration. Bubbles of the carbon dioxide gas fill the flour mix and increase its volume. This is the basis of the use of yeast in the baking industry for making breads, pastries and cakes.<\/p>\n

    Question 4.
    \nWhat is pseudopodia? Write down two examples.<\/p>\n

    Answer:
    \nPseudopodia: A pseudopodium is a temporary arm-like projection of the cell of a microorganism.<\/p>\n

    Examples :
    \nPseudopodia are used for motility.
    \nPseudopodia are used for ingestion.<\/p>\n

    Microorganisms: Friend and Foe Class 8 Extra Questions Short Answer Type 2<\/h3>\n

    Question 1.
    \n(a) What are antibiotics?
    \n(b) Name any two antibiotics?
    \n(c) How are antibiotics manufactured?<\/p>\n

    Answer:
    \n(a) Antibiotics are the medicines which kill or stop the growth of the disease-causing microorganisms. The source of these medicines is micro\u00adorganisms.
    \n(b) Streptomycin, Tetracycline.<\/p>\n

    (c) The antibiotics are manufactured by growing specific microorganisms which checks the growth of some other bacteria or microorganisms. Antibiotics are used to cure a variety of diseases. They are also used to control many plant diseases.<\/p>\n

    \"Microorganisms:<\/p>\n

    Question 2.
    \nHow are bacteria beneficial to us? Explain by giving any three examples.
    \nAnswer:
    \nBacteria are very useful to human beings though some other bacteria are harmful too.<\/p>\n

    Following are some examples that are very useful to us :<\/p>\n

    (a) Rhizobium: Rhizobium bacteria and blue-green algae present in the soil fix nitrogen from the atmosphere and convert into nitrogenous compounds.
    \n(b) Lactobacillus: Lactobacillus bacteria is useful in making curd from milk.
    \n(c) Decomposers: Bacteria play an important role in cleaning the environment by decomposing the dead organic matter.<\/p>\n

    Question 3.
    \nHow can nitrogen be replenished in soil? Explain with an example.
    \nAnswer:
    \nNitrogen in the soil can be replenished by two different ways:<\/p>\n

    Rhizobium bacteria present in the nodules of the roots of leguminous plants helps in the replenishment of the soil with nitrogen. Rhizobium bacteria takes nitrogen from the atmosphere and fix it directly into nitrogenous compounds. These crops are like beans and peas which with which it has a symbiotic relationship Rhizobium.<\/p>\n

    Nitrogen sometimes gets fixed through the action of lightning in the clouds. High temperature generated in the lightening fixes the nitrogen to nitrogenous compounds.<\/p>\n

    Microorganisms: Friend and Foe Class 8 Extra Questions Long Answer Type<\/h3>\n

    Question 1.
    \nWhat is nitrogen cycle? Describe with the help of a diagram how nitrogen- cycle works.
    \nAnswer:
    \nThe process of consumption of nitrogen by living beings (animals and plants), taking it from the atmosphere and returning back to the atmosphere by various processes, is called nitrogen cycle.<\/p>\n

    Nitrogen-cycle:<\/p>\n

    (i) Nitrogen is one of the essential constituents pf all living organisms as part of proteins, chlorophyll, nucleic acids and vitamins.
    \n(ii) The atmospheric nitrogen cannot be taken directly by plants and animals.
    \n(iii) The nitrogen-fixing bacteria and algae present in the soil fix nitrogen from the atmosphere and convert into nitrite and nitrate forms.
    \n(iv) Once nitrogen is converted into these usable forms, it can be utilized by plants through their roots. This is called the process of \u2018fixing of nitrogen.
    \nimage
    \n(v) Nitrogen is then used for the synthesis of amino acids, proteins, etc. in plants. Animals feeding on the plants thus get these nitrogen-containing compounds.
    \n(vi) When plants and animals die, bacteria and fungi present in the soil convert the various compounds of nitrogen back to nitrates and nitrites. Certain specialized bacteria convert nitrates and nitrites into nitrogen gas which goes back into the atmosphere. As a result, the percentage of nitrogen in the atmosphere remains more or less constant. This is how nitrogen-works.<\/p>\n

    Hope the knowledge provided regarding the Microorganisms: Friend and Foe Class 8 Extra Questions and Answers has helped you to the possible extent. For more info feel free to reach us and we will guide you at the earliest possibility. Stay connected to our site to avail latest updates on Extra Questions for Various Classes instantly.<\/p>\n","protected":false},"excerpt":{"rendered":"

    Microorganisms: Friend and Foe Class 8 Extra Questions and Answers Science Chapter 2 PDF are solved by experts and will guide students in the right direction. Students can get how to tackle different questions easily by solving the Extra Questions for Class 8 Science Question bank on a regular basis. Class 8 Science Chapter 2 …<\/p>\n

    Microorganisms: Friend and Foe Class 8 Extra Questions and Answers Science Chapter 2<\/span> Read More »<\/a><\/p>\n","protected":false},"author":9,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"site-sidebar-layout":"default","site-content-layout":"default","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","theme-transparent-header-meta":"default","adv-header-id-meta":"","stick-header-meta":"default","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","spay_email":""},"categories":[7],"tags":[],"yoast_head":"\nMicroorganisms: Friend and Foe Class 8 Extra Questions and Answers Science Chapter 2 - MCQ Questions<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/mcq-questions.com\/microorganisms-friend-and-foe-class-8-extra-questions\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Microorganisms: Friend and Foe Class 8 Extra Questions and Answers Science Chapter 2 - MCQ Questions\" \/>\n<meta property=\"og:description\" content=\"Microorganisms: Friend and Foe Class 8 Extra Questions and Answers Science Chapter 2 PDF are solved by experts and will guide students in the right direction. 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