{"id":648,"date":"2016-02-28T08:12:00","date_gmt":"2016-02-28T02:42:00","guid":{"rendered":""},"modified":"2020-08-01T01:27:10","modified_gmt":"2020-07-31T19:57:10","slug":"textbook-answers-and-solutions-of-cbse-class-viii-science-chapter-7-conservation-of-plants-and-animals","status":"publish","type":"post","link":"https:\/\/cbsencertanswers.com\/2016\/02\/textbook-answers-and-solutions-of-cbse-class-viii-science-chapter-7-conservation-of-plants-and-animals.html","title":{"rendered":"TEXTBOOK ANSWERS AND SOLUTIONS OF CBSE CLASS VIII SCIENCE Chapter 7 CONSERVATION OF PLANTS AND ANIMALS"},"content":{"rendered":"
\n
\n<\/div>\n
\n<\/div>\n
\n<\/div>\n
\nExercise<\/span><\/u><\/b><\/o:p><\/span><\/u><\/b><\/div>\n
\n<\/div>\n
\n1)
\nFill in the blanks<\/o:p><\/span><\/b><\/div>\n
\n
<\/span><\/b><\/div>\n
\n(a) A place where animals are
\nprotected in their natural habitat is called a __sanctuary__.<\/o:p><\/span><\/div>\n
\n(b) Species found only in a particular
\narea are known as __endemic__.<\/span><\/o:p><\/span><\/div>\n
\n(c) Migratory birds fly to far away
\nplaces because of __climatic__ changes.<\/span><\/o:p><\/span><\/div>\n
\n<\/div>\n
\n2)
\nDifferentiate between the following.<\/o:p><\/span><\/b><\/div>\n
\n(a)
\nWildlife sanctuary and biosphere reserve<\/o:p><\/span><\/b><\/div>\n
\n(b)
\nZoo and wildlife sanctuary<\/o:p><\/span><\/b><\/div>\n
\n(c)
\nEndangered and extinct species<\/o:p><\/span><\/b><\/div>\n
\n(d)
\nFlora and fauna<\/o:p><\/span><\/b><\/div>\n
\n<\/div>\n
\nANSWER:-<\/span><\/o:p><\/span><\/div>\n
\na) Wildlife Sanctuary:-It is an<\/span> area within which
\nanimals are protected from possible dangers
\nsuch as hunting. Their habitat is also conserved in this area.<\/o:p><\/span><\/div>\n
\n-It provides protection and<\/span> suitable living
\nconditions to wild animals.<\/o:p><\/span><\/div>\n
\n<\/div>\n
\nBiosphere Reserve:-It is a large<\/span> protected area
\nconstructed for the conservation of
\nbiodiversity.<\/o:p><\/span><\/div>\n
\n-It helps in the conservation of
\nvarious life forms such as plants, animals, and micro- organisms.<\/span><\/o:p><\/span><\/div>\n
\n<\/div>\n
\nb) Zoo-Zoos are smaller places<\/span> having some animals
\nprotected for the public view.<\/o:p><\/span><\/div>\n
\n-It is an artificial habitat.<\/span><\/o:p><\/span><\/div>\n
\n-It provides protection only.<\/span><\/o:p><\/span><\/div>\n
\n<\/div>\n
\nWildlife Sanctuary:-Wildlife<\/span> Sanctuary are larger places
\nhaving wild animals in their natural habitat<\/o:p><\/span><\/div>\n
\n-It conserves the natural habitat of
\nanimals.<\/span><\/o:p><\/span><\/div>\n
\n-It provides protection and suitable
\nliving condition to wild<\/span> animals.<\/o:p><\/span><\/div>\n
\n<\/div>\n
\nc) Endangered-It is a population of<\/span> species that is on the
\nverge of becoming extinct.<\/o:p><\/span><\/div>\n
\n<\/div>\n
\nExtinct-It is a
\npopulation of species that no longer exists. Hence, it is extinct.<\/o:p><\/span><\/div>\n
\n<\/div>\n
\nd) Flora-It refers to all living
\nplants in a particular area.<\/span><\/o:p><\/span><\/div>\n
\n<\/div>\n
\nFauna-It refers to all
\nanimals living in a particular area.<\/o:p><\/span><\/div>\n
\n<\/div>\n
\n3) Discuss the effects of deforestation
\non the following.<\/o:p><\/span><\/b><\/div>\n
\n
<\/span><\/b><\/div>\n
\n<\/div>\n
\n
<\/span><\/b><\/div>\n
\n<\/div>\n
\nANSWER:-<\/span>a) Wild animals: When forests are cut,
\nthe natural habitat of the animals is destroyed. Without the natural habitat
\nthe animals are left with no place to live and breed. As a result of this many
\nanimals are at<\/span> the verge of extinction.<\/o:p><\/span><\/div>\n
\n
<\/span><\/div>\n
\nb) Effects of deforestation on the
\nenvironment: Plants absorb <\/span>CO<\/span>2<\/sub> from the atmosphere to perform photosynthesis.
\nIf plants are destroyed, then the level of <\/span>CO<\/span>2<\/sub> in the atmosphere will rise.<\/span><\/o:p><\/span><\/div>\n
\nAs a result, <\/span>CO<\/span>2 <\/sub>will trap more heat
\nradiations, thereby adding to global warming. An increase in<\/span> the temperature of the
\nEarth will disturb the natural water cycle. As a result, there will be a change
\nin the rainfall pattern. This could lead to floods or droughts.<\/o:p><\/span><\/div>\n
\n
<\/span><\/div>\n
\nc) Roots of plants hold
\nsoil particles together. In the absence of plants, the top layer of the soil
\nwill be easily removed by the action of high speed
\nwinds or water flow. Thus, deforestation increases
\nthe chances of soil erosion. As a result, soil loses humus and become less
\nfertile.<\/o:p><\/span><\/div>\n
\n
<\/span><\/div>\n
\nd)Deforestation in
\ncities can increase the risk of many natural calamities such as floods and
\ndroughts in that area. Also, it can lead to global warming due to an increase
\nin the level of <\/span>CO<\/span>2<\/sub> in the atmosphere as a result of vehicular and industrial pollution.<\/o:p><\/span><\/div>\n
\n
<\/span><\/div>\n
\ne) As a result of deforestation,
\nchances of desertification, droughts, floods, etc. increase. Deforestation can
\nalso increase the level of <\/span>CO<\/span>2<\/sub> in the Earth. It will lead to an increase in
\ntemperature i.e., global warming. As a result, the entire natural water cycle
\nwill get disrupted<\/span><\/o:p><\/span><\/div>\n
\n
<\/span><\/div>\n
\nf) Deforestation is slowly changing
\nour environmental conditions. It is responsible for global warming, soil
\nerosion, greenhouse effect,<\/span> drought, floods, and many other global problems. As a
\nresult, the next generation will have to face severe
\nconsequences of deforestation.<\/o:p><\/span><\/div>\n
\n<\/div>\n
\n4)
\nWhat will happen if?<\/o:p><\/span><\/b><\/div>\n
\n(a)
\nWe go on cutting trees.<\/o:p><\/span><\/b><\/div>\n
\n(b)
\nThe habitat of an animal is disturbed.<\/o:p><\/span><\/b><\/div>\n
\n(c)
\nThe top layer of soil is exposed<\/o:p><\/span><\/b><\/div>\n
\n<\/div>\n
\nANSWER:<\/span>-a) If we go on cutting trees, the
\nnatural habitat of many animals will get completely destroyed. As a result, the
\nbiodiversity of many areas will be<\/span>
\nseverely affected. Also, there will be an increase in
\nthe temperature of the Earth as a result of global
\nwarming, which can disturb the natural water cycle. As a result, there will be
\na change in the rainfall pattern. This could
\nlead to floods or droughts. This will also increase the risk of soil erosion,
\ndesertification, and natural calamities.<\/o:p><\/span><\/div>\n
\n
<\/span><\/div>\n
\n(b) The habitat of an animal provides
\nit with necessities such as shelter, food, and protection.<\/span><\/o:p><\/span><\/div>\n
\n
<\/span><\/div>\n
\nIf the habitat of an animal is disturbed,
\nthen it will be forced to go to other places in search of<\/span> food and shelter. The
\nanimal could get killed by other animals in this process.<\/o:p><\/span><\/div>\n
\n
<\/span><\/div>\n
\n(c) If the top layer of soil is l
\nexposed, then it will gradually expose the lower layer of soil, which is hard
\nand rocky in nature. This type of soil is less fertile as it contains less
\nhumus. Continued soil erosion will make the land barren or infertile.<\/span><\/o:p><\/span><\/div>\n
\n<\/div>\n
\n5)
\nAnswer in brief:<\/o:p><\/span><\/b><\/div>\n
\n(a)
\nWhy should we conserve biodiversity?<\/o:p><\/span><\/b><\/div>\n
\n(b)
\nProtected forests are also not completely safe for wild animals. Why?<\/o:p><\/span><\/b><\/div>\n
\n(c)
\nSome tribals depend on the jungle. How?<\/o:p><\/span><\/b><\/div>\n
\n(d)
\nWhat are the causes and consequences of deforestation?<\/o:p><\/span><\/b><\/div>\n
\n(e)
\nWhat is Red Data Book?<\/o:p><\/span><\/b><\/div>\n
\n(f)
\nWhat do you understand by the term migration?<\/o:p><\/span><\/b><\/div>\n
\n<\/div>\n
\nANSWER
\n:<\/span>– (a) Biodiversity
\nrefers to the number and variety of various life forms such as plants, animals,
\nand micro-organisms in an area. Plants and animals<\/span> depend on each other
\nfor survival. This means that the destruction of either of the two will affect
\nthe life of the other. Hence, we need to conserve
\nbiodiversity to maintain the balance of nature.<\/o:p><\/span><\/div>\n
\n
<\/span><\/div>\n
\n(b) Protected forests are not
\ncompletely safe for wild animals because people who live near or<\/span> adjacent to forests use
\nresources from forests to <\/span>fulfill<\/span> their own requirements. In this process, wild<\/span><\/span>
\nanimals are killed and sold for lucrative amounts of
\nmoney.<\/o:p><\/span><\/span><\/div>\n
\n
<\/span><\/span><\/div>\n
\n(c) Tribals gather food, fodder, and
\nfallen branches of trees from forests. Hence, they depend on forests for their
\ndaily requirement<\/span><\/o:p><\/span><\/div>\n
\n
<\/span><\/div>\n
\n(d) Causes of deforestation:<\/span><\/o:p><\/span><\/div>\n
\n(i) Forests are cleared for accommodating
\nexpanding urban areas and for fulfilling their<\/span>
\never-increasing requirements.<\/o:p><\/span><\/div>\n
\n(ii) Forests are destroyed to clear
\nland for crops and cattle grazing.<\/span><\/o:p><\/span><\/div>\n
\n(iii) Trees are cut down to be used
\nfor firewood.<\/span><\/o:p><\/span><\/div>\n
\nConsequences of deforestation:<\/span><\/o:p><\/span><\/div>\n
\n(i) Soil erosion<\/span><\/o:p><\/span><\/div>\n
\n(ii) Loss of biodiversity<\/span><\/o:p><\/span><\/div>\n
\n(iii) Floods and droughts<\/span><\/o:p><\/span><\/div>\n
\n(iv) Climate change due to global
\nwarming<\/span><\/o:p><\/span><\/div>\n
\n(v) Disruption of water cycle<\/span><\/o:p><\/span><\/div>\n
\n
<\/span><\/div>\n
\n(e) Red Data Book is a source book
\nthat maintains an international list of all endangered<\/span> animal and plant
\nspecies. This book is maintained by IUCN (International Union for Conservation of Nature and Natural resources).<\/o:p><\/span><\/div>\n
\n
<\/span><\/div>\n
\n(f) Migration refers to the movement
\nof an organism or a group of organisms from its<\/span>
\nnatural habitat to another place at a particular time
\nevery year<\/o:p><\/span><\/div>\n
\n<\/div>\n
\n6)
\nIn order to meet the ever-increasing demand in factories and for shelter, trees
\nare being continually cut. Is it justified to cut trees for such projects?
\nDiscuss and prepare a brief report.<\/o:p><\/span><\/b><\/div>\n
\n
<\/span><\/b><\/div>\n
\n<\/div>\n
\n
<\/span><\/b><\/div>\n
\n<\/div>\n
\nANSWER:-<\/span>No. It is not at all justified to cut
\ntrees to meet the ever increasing demands of human population. Forests are the
\nhabitat of several organisms including wild animals. They provide us with good
\nquality air as they give out O<\/span>2<\/span> and absorb the harmful <\/span>CO2<\/sub><\/span> gas from the
\natmosphere. In the process, they prevent the excessive heating of the
\natmosphere. They prevent soil erosion and natural calamities such as floods and
\ndroughts. They increase the fertility of the soil and help conserve
\nbiodiversity. The cutting of forests to meet the demands of growing human
\npopulation will lead to global<\/span> warming, soil erosion, greenhouse effect, droughts, floods,
\nand many more problems. The destruction of forests will disturb the balance of
\nnature.<\/o:p><\/span><\/div>\n
\n<\/div>\n
\n7)
\nHow can you contribute to the maintenance of green wealth of your locality?
\nMake a list of actions to be taken by you.<\/o:p><\/span><\/b><\/div>\n
\n<\/div>\n
\nANSWER:-<\/span>I can help in maintaining the green
\nwealth of locality by taking care of the plants and trees growing in or around
\nmy locality. I can plant more and more trees. I can also encourage the<\/span> people in my locality
\nto plant more trees by informing them about the importance of growing trees. I
\ncan make young children aware of the effects
\nthat deforestation has on our environment and on our planet. I can also ask them
\nto water the plants daily, which will take very little of their time.<\/o:p><\/span><\/div>\n
\n<\/div>\n
\n8)
\nExplain how deforestation leads to reduced rainfall.<\/o:p><\/span><\/b><\/div>\n
\n<\/div>\n
\nANSWER:<\/span>-Deforestation is the removal of trees
\nor other vegetation from an area for industrial, agricultural, or other purposes.
\nPlants or trees absorb <\/span>CO<\/span>2<\/sub> from the atmosphere. If plants are destroyed, then
\nthe level of <\/span>CO<\/span>2<\/sub> in the atmosphere will rise. The high levels of <\/span>CO<\/span>2<\/sub> in<\/span> the atmosphere will
\ntrap more heat radiations, leading to global warming. This increase in
\ntemperature of the Earth will disturb the natural water cycle. As a result of
\ndisruption in the water cycle, there will be a
\nchange in the rainfall pattern.<\/o:p><\/span><\/div>\n
\n<\/div>\n
\n10)
\nWhy should paper be saved? Prepare a list of ways by which you can save paper.<\/o:p><\/span><\/b><\/div>\n
\n<\/div>\n
\nANSWER:<\/span> – Paper should be saved because it
\ntakes around<\/span> seventeen full grown trees to make one tonne of paper.
\nTrees, as we know, are important to maintain a
\nbalance of nature. Therefore, in order to save trees and prevent the impact of
\ntheir loss on living organisms, we need to save
\npaper.<\/o:p><\/span><\/div>\n
\nWays by which paper can be saved:<\/span><\/o:p><\/span><\/div>\n
\n
<\/span><\/div>\n
\n(i) Collect used paper and recycle it.<\/span><\/o:p><\/span><\/div>\n
\n(ii) Use both sides of a paper for
\nwriting.<\/span><\/o:p><\/span><\/div>\n

<\/p>\n

\n<\/div>\n<\/div>\n