{"id":4336,"date":"2020-08-28T08:54:59","date_gmt":"2020-08-28T03:24:59","guid":{"rendered":"https:\/\/kseebsolutions.guru\/?p=4336"},"modified":"2021-07-02T15:04:07","modified_gmt":"2021-07-02T09:34:07","slug":"kseeb-solutions-class-8-science-chapter-2","status":"publish","type":"post","link":"https:\/\/kseebsolutions.guru\/kseeb-solutions-class-8-science-chapter-2\/","title":{"rendered":"KSEEB Solutions for Class 8 Science Chapter 2 Our Environments"},"content":{"rendered":"

Karnataka Board Class 8 Science Chapter 2 Our Environment<\/h2>\n

KSEEB Class 8 Science Chapter 2 Textual Questions & Answers<\/h3>\n

I. Four alternatives are given to each of the following incomplete statements. Choose the right answer.<\/p>\n

Question 1.
\nFill in the box with an appropriate organism.
\nGrass \u2192 ____________ \u2192 Frog\u2192 Snake \u2192 Eagle
\n(a) deer
\n(b) lizard
\n(c) grasshopper
\n(d) rat
\nAnswer:
\n(c) grasshopper<\/p>\n

Question 2.
\nOne of these is a decomposer.
\n(a) fungi
\n(b) algae
\n(c) protozoa
\n(d) insect
\nAnswer:
\n(a) fungi<\/p>\n

II. Fill In The Blanks With Suitable Words:<\/p>\n

Question 1.
\nThe crust of the Earth is called ……….
\nAnswer:
\nLithosphere<\/p>\n

Question 2.
\nThe basic unit of study in the environment is ……….
\nAnswer:
\nOrganism<\/p>\n

Question 3.
\nA group of individuals belonging to the same species is ……….
\nAnswer:
\nPopulation<\/p>\n

Question 4.
\nDifferent kinds of the ecosystem together constitute ………….
\nAnswer:
\nBiosphere<\/p>\n

Question 5.
\nIn a parasitic food chain, the pyramid of the number will be ……….
\nAnswer:
\ninverted.<\/p>\n

III. Answer the following:<\/p>\n

Question 1.
\nList the factors which have made life to exist on the Earth.
\nAnswer:
\nThe factors which have made the life to exist on the earth are as follow<\/p>\n

    \n
  1. The presence of water has some unique physical and chemical properties that are essential for supporting life\u2019s existence.<\/li>\n
  2. As the photosynthetic algae appeared on earth the oxygen concentration increased which is ideal for the other life forms.<\/li>\n
  3. An atmosphere which is a mixture of gases water vapour to support and Sustain life.<\/li>\n
  4. Lithosphere allows life to flourish unlike the barren surface of other plants.<\/li>\n<\/ol>\n

    Question 2.
    \nDefine the following
    \n1. Lithosphere
    \n2. Population
    \n3. Biotic community
    \n4. Food web
    \n5.Tropic level<\/p>\n

    Answer:<\/p>\n

      \n
    1. Lithosphere: The surface or crust of the earth is called the lithosphere. It accompanies the mountains, ocean floors, and the plane lands.<\/li>\n
    2. Population:\u00a0 A collection of individuals belonging to the same species occupying a given area at a given time is called population.<\/li>\n
    3. Biotic community: The living components are called biotic components.
      \nEg: plants, animals, bacteria, and fungi.<\/li>\n
    4. Food web: Since most organisms feed on more than one kind of food item. Every organism at even tropic level becomes linked to several food chains at the same time. A complex network of interconnected food chains forming a food web.<\/li>\n
    5. Tropic level: Representation of the different levels of feeding in the ecosystem is described as tropic levels.<\/li>\n<\/ol>\n

      Question 3.
      \nWhat is an ecosystem?
      \nAnswer:
      \nAn interaction between living and non-living components is known as the ecosystem.<\/p>\n

      Question 4.
      \nWhy is the use of DDT not advisable.
      \nAnswer:
      \nThe indiscriminate use of DDT has resulted in biomagnification in the tropic level. A gradual increase in the concentration of DDT is has been detected in the tissues of small fishes; predatory birds and also in mother\u2019s milk, therefore it is not advisable to use DDT.<\/p>\n

      Question 5.
      \nConstruct a simple food chain.
      \nAnswer:
      \nGrass \u2192 deer \u2192 tiger<\/p>\n

      Question 6.
      \nWhat may happen if all herbivores arc killed in a tern trial ecosystem?
      \nAnswer:
      \nIf all the herbivores are killed the number of producers will increase and the secondary and tertiary consumers will die of starvation, Thus the nutritional relationship \u2018eating and being eaten\u2019 will be unstable.<\/p>\n

      Question 7.
      \nIn any food chain tropic level – 1 is occupied by green plants. Give reason.
      \nAnswer:
      \nThe first trophic level of the food chain is always occupied by green plants which are termed to be producers. This is because producers directly absorb sunlight, the abiotic factor, and fix it into the food chain. This energy is transferred to organisms in other trophic levels of the food chain.<\/p>\n

      KSEEB Class 8 Science Chapter 2 Additional Questions & Answers<\/h3>\n

      Question 1.
      \nExplain the formation of the earth.
      \nAnswer:
      \nWhen the earth was formed about 4.8 billion of years ago. Earth was a hot revolving ball of gas. The extremely high temperature and the dry climate of the earliest earth would have made it impossible for the life to appear and exist. The first multicellular organisms appeared about 1.4 billion years ago. These organisms and the other forms of life which evolved from them could survive when the condition on earth began to stabilize gradually.<\/p>\n

      Question 2.
      \nWhat is hydrosphere?
      \nAnswer:
      \nThe surface of the earth is covered by water. This part of the earth is called hydrosphere.<\/p>\n

      Question 3.
      \nWater has some unique physical \u2018and chemical properties seen in other substances. Which are essential for supporting life\u2019s existence. What are they?
      \nAnswer:<\/p>\n

        \n
      1. Water requires a considerable amount of energy to get heated up and also to get converted from a liquid state into a gaseous state. On a very hot day, water bodies help maintain atmosphere temperature cool by absorbing heat from the sun. When the sun\u201d sets. The heat which water has absorbed is returned to the atmosphere, as water evaporates. Such regulation is crucial for the survival of living organisms.<\/li>\n
      2. Water has a high resistance to sudden changes in temperature and this feature makes water an excellent habitat for most organisms.<\/li>\n
      3. At 4\u00b0 water can expand on cooling or heating this feature ensures that all the water in a water body will be close to 0\u00b0 c before any freezing can occur.<\/li>\n
      4. The high surface tension of water and its tendency to expand on freezing helps in the weathering of rocks. 1 ending to soil formation.<\/li>\n<\/ol>\n

        Question 4.
        \nExplain How did friendly atmosphere evolve on the earth?
        \nAnswer:
        \nAtmosphere of the earth at its beginning was rich in carbon dioxide and oxygen content was very less. As photosynthetic algae appeared on earth oxygen concentration increased resulting in a shift from reducing the type of atmosphere to an oxidizing type Gradually atmosphere reached its present composition. Which is ideally suited for humans and other forms of life?<\/p>\n

        Question 5.
        \nWhat is Lithosphere?
        \nAnswer:
        \nThe Surface or crust of the earth is called the lithosphere.<\/p>\n

        Question 6.
        \nWhat is the biosphere?
        \nAnswer:
        \nThe hydrosphere, atmosphere, and lithosphere of the earth together constitute the biosphere. It is the sum total of all organisms and their places of living.<\/p>\n

        Question 7.
        \nWhat is ecology?
        \nAnswer:
        \nThe Scientific studies which enable us to understand the totality and pattern of the relations between organisms and their environment is called ecology.<\/p>\n

        Question 8.
        \nWhat are the basic laws of ecology?
        \nAnswer:
        \nThe basic laws of ecology are.<\/p>\n

          \n
        1. We can never continue to do anything in nature.<\/li>\n
        2. In nature, everything is connected to everything else.<\/li>\n<\/ol>\n

          Question 9.
          \nWrite the levels of organization in nature.
          \nAnswer:
          \nThe level of organization in nature is Species \u2192 Population \u2192 biotic community \u2192 ecosystem \u2192 biosphere.<\/p>\n

          Question 10.
          \nDefine the following terms.
          \n1. Organism
          \n2. Species
          \n3. Population
          \n4. Biotic components
          \n5. Ecosystem
          \n6. biotic components.
          \nAnswer:<\/p>\n

            \n
          1. Organism:\u00a0 Any form of life can be called an organism.<\/li>\n
          2. Species: Species is a group of similar organisms sharing common genetic structure and capable of breeding among themselves.<\/li>\n
          3. Population:\u00a0 A collection of individuals belonging to the same species occupying a given area at a given time is called population.<\/li>\n
          4. Biotic components:\u00a0 The living components are called biotic components.
            \nEg: plants, animals, bacteria, and fungi.<\/li>\n
          5. Ecosystem:\u00a0 An interaction between living and non-living components is known as the ecosystem.<\/li>\n
          6. biotic component:\u00a0 The non\u00acliving components are called as biotic components.
            \nEg: Air, water, land, sun, light<\/li>\n<\/ol>\n

            Question 11.
            \nName the types of ecosystems.
            \nAnswer:
            \nNatural ecosystem can be broadly classified into two types. They are ;<\/p>\n

              \n
            1. aquatic ecosystem<\/li>\n
            2. terrestrial ecosystem.<\/li>\n<\/ol>\n

              Question 12.
              \nList a few examples of the man-made ecosystem.
              \nAnswer:
              \nAquarium, Garden, Terrace Garden, zoological park.<\/p>\n

              Question 13.
              \nWhat is meant by a food chain? write any two food chains.
              \nAnswer:
              \nThe kind of nutritional relationship where the food energy is getting transferred from one tropic level to another is called a food chain.
              \nEg:
              \n1. Grass \u2192 Grasshopper \u2192 Frog \u2192 Snake.
              \n2. Algae \u2192 Insect large \u2192 fishes \u2192 Aquatic birds.
              \n3. Grass \u2192 Rabbit \u2192 Wolf.<\/p>\n

              Question 14.
              \nWhat is meant by grazing or herbivorous food chain?
              \nAnswer:
              \nThe food chain in which the primary consumers are plant-eating animals is called grazing or herbivorous food chain. This is also called a predatory food chain.
              \nEx: Grass \u2192 deer\u2192 tiger.
              \nGrass \u2192 Rabbit \u2192 wolf.<\/p>\n

              Question 15.
              \nWhat is a detritivorous food chain? give example.
              \nAnswer:
              \nThe food chain in which, the primary consumers are a detrivore is called a detritivorous food chain.
              \nEx: Fallen leaves \u2192 termites \u2192 birds.<\/p>\n

              Question 16.
              \nWhat is meant by the parasitic food chain? give example.
              \nAnswer:
              \nThe food chain in which the transfer of food energy occurs through a series of parasites at each trophic level is called the parasitic food chain.
              \nEx: Tree \u2192 birds \u2192 lice \u2192 protozoans.<\/p>\n

              Question 17.
              \nAnts, termites are called detrivore why?
              \nAnswer:
              \nAnts, termites, earthworms are called detrivores because they feed on detritus.<\/p>\n

              Question 18.
              \nDefine the food web? draw a simple food web.
              \nAns. A complex network of interconnected food chains forming a food web.
              \n\"KSEEB<\/p>\n

              Question 19.
              \nHow does food become energy in an organism?
              \nAnswer:
              \nVarious organisms found in an ecosystem are constantly growing, reproducing, dying, and decaying. They need energy for all their activities. When organisms consume food the carbohydrates in their food become the source of energy. This energy their food becomes the source of energy. This energy is released as you are aware through a process called respiration. It makes the stored energy in the carbohydrates available for biological work.<\/p>\n

              Question 20.
              \nWhich is the main source of energy for all ecosystem?
              \nAnswer:
              \nThe main source of energy for all ecosystems is solar energy.<\/p>\n

              Question 21.
              \nDraw a food chain with five tropic levels.
              \nAnswer:<\/p>\n

              \"KSEEB<\/p>\n

              Question 22.
              \nDraw a picture of energy flow in nature.
              \nAnswer:<\/p>\n

              \"KSEEB<\/p>\n

              Question 23.
              \nDefine ecological pyramids?
              \nAnswer:
              \nThe graphical representation of the relationship between the energy number of individuals and their biomass at each tropic level in the form of a pyramid are called ecological pyramids.<\/p>\n

              Question 24.
              \nDefine the following.
              \n1. Pyramid of numbers
              \n2. Pyramid of biomass
              \n3. Pyramid of energy
              \nAnswer:<\/p>\n

                \n
              1. Pyramid of biomass: A Pyramid constructed in the view of biomass, which is the dry weight of all the matter in the organisms at a tropic level is called the pyramid of biomass.<\/li>\n
              2. \u00a0Pyramid of numbers: A Pyramid constructed based on the number of individuals occupying a given tropic level at a given period of time is called the pyramid of numbers.<\/li>\n
              3. \u00a0Pyramid of energy: A Pyramid constructed on the basis of the amount of energy fixed at each level is called the pyramid of energy.<\/li>\n<\/ol>\n

                Question 25.
                \nDraw a graphical representation of an upright pyramid of number
                \nAnswer:
                \n\"KSEEB<\/p>\n

                Question 26.
                \nDraw an Inverted pyramid of numbers.
                \nAnswer:
                \n\"KSEEB<\/p>\n

                Question 27.
                \nThe pyramid of energy will be always upright. Give reason
                \nAnswer:
                \nIn any ecosystem. For any food chain, the pyramid of energy. Will be always upright because the amount of usable energy available at each trophic level is about 10% of the energy that was available at the previous tropic level.<\/p>\n

                Question 28.
                \nWhat is meant by biomagnification?
                \nAnswer:
                \nAn increase in the concentration of a toxic substance or a pollutant, with every link in the food chain, is called biomagnification.<\/p>\n

                Question 29.
                \nWhy is the use of DDT not advisable?
                \nAnswer:
                \nThe indiscriminate use of DDT has resulted in biomagnification in the tropic level. A gradual increase in the concentration of DDT is has been detected in the tissues of small fishes; predatory birds and also in mother\u2019s milk, therefore it is not advisable to use DDT. It is a non-biodegradable substance. DDT is chemically called Dichloro Diphenyl Trichloroethane<\/p>\n

                KSEEB Solutions for Class 8 Science<\/a><\/h4>\n","protected":false},"excerpt":{"rendered":"

                Karnataka Board Class 8 Science Chapter 2 Our Environment KSEEB Class 8 Science Chapter 2 Textual Questions & Answers I. Four alternatives are given to each of the following incomplete statements. Choose the right answer. Question 1. Fill in the box with an appropriate organism. Grass \u2192 ____________ \u2192 Frog\u2192 Snake \u2192 Eagle (a) deer …<\/p>\n","protected":false},"author":5,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[6],"tags":[],"jetpack_sharing_enabled":true,"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/kseebsolutions.guru\/wp-json\/wp\/v2\/posts\/4336"}],"collection":[{"href":"https:\/\/kseebsolutions.guru\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/kseebsolutions.guru\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/kseebsolutions.guru\/wp-json\/wp\/v2\/users\/5"}],"replies":[{"embeddable":true,"href":"https:\/\/kseebsolutions.guru\/wp-json\/wp\/v2\/comments?post=4336"}],"version-history":[{"count":0,"href":"https:\/\/kseebsolutions.guru\/wp-json\/wp\/v2\/posts\/4336\/revisions"}],"wp:attachment":[{"href":"https:\/\/kseebsolutions.guru\/wp-json\/wp\/v2\/media?parent=4336"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/kseebsolutions.guru\/wp-json\/wp\/v2\/categories?post=4336"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/kseebsolutions.guru\/wp-json\/wp\/v2\/tags?post=4336"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}