How are even small animals
Question: How are even small animals important in an ecosystem? Solution: Small animals might be small in size but their role in ecosystem is very important which cannot be ignored. They are the part of food chains and food webs which are essential for maintaining balance in nature....
Read More →Why are endemic organisms
Question: Why are endemic organisms in greater danger of becoming extinct? Solution: Endemic organisms are confined to a limited geographical area. They cannot adapt or live outside their natural habitat. This means any disturbance to their habitat will adversely affect them. Thus, they are in greater danger of becoming extinct....
Read More →If the radius of a sphere is measured as 7 m with an error of 0.02 m, find the approximate error in calculating its volume.
Question: If the radius of a sphere is measured as 7 m with an error of 0.02 m, find the approximate error in calculating its volume. Solution: Letxbe the radius of the sphere andybe its volume. $y=\frac{4}{3} \pi x^{3}$ Let $\Delta x$ be the error in the radius. $x=7$ $\Delta x=0.02$ $\frac{d y}{d x}=4 \pi x^{2}$ $\Rightarrow\left(\frac{d y}{d x}\right)_{x=7}=196 \pi$ $\therefore \Delta y=d y=\frac{d y}{d x} d x=196 \pi \times 0.02=3.92 \pi$ Hence, the approximate error in calculating the volum...
Read More →Why are wildlife sanctuaries
Question: Why are wildlife sanctuaries important for conservation of plants and animals? Solution: In a wildlife sanctuary, killing and capturing of wild animals is strictly prohibited. Any human activity which disturbs the wild animals and plants or their habitat is not allowed. So, in these areas, animals live in natural environment protected from any interference. This is why, sanctuaries are important....
Read More →Name the first reserve forest of India.
Question: Name the first reserve forest of India. Solution: Satpura National Park located in Madhya Pradesh is the first reserve forest of India....
Read More →Can a forest regenerate
Question: Can a forest regenerate naturally in a short period of time? Solution: Reforestation (i.e. regeneration of a forest) can take place naturally by leaving the deforested area undisturbed for some time. During this period, the area re-establishes itself without the interference of human beings by the natural growth of trees. This process, however takes a long time in terms of years....
Read More →State whether the following statements
Question: State whether the following statements are True or False. Correct the false statements. (i) There can be a wildlife sanctuary within a biosphere reserve. (ii) Plants of a particular area are collectively termed as fauna. (iii) Deforestation leads to an increase in the water holding capacity of the soil. (iv) Bison is an endemic fauna of Pachmarhi biosphere reserve. Solution: 1.True 2.False, Plants of a particular area are collectively termed as flora. 3.False, Deforestation leads to de...
Read More →Find the approximate change in the surface area
Question: Find the approximate change in the surface area of a cube of sidexmetres caused by decreasing the side by 1%. Solution: Letybe the surface area of the cube. $y=6 x^{2}$ We have $\frac{\Delta x}{x} \times 100=1$ Now, $\frac{d y}{d x}=12 x$ $\Rightarrow \Delta y=d y=\frac{d y}{d x} d x=12 x \times \frac{x}{100}=0.12 x^{2} \mathrm{~m}^{2}$ Hence, approximate change in the surface area of the cube is $0.12 x^{2} \mathrm{~m}^{2}$....
Read More →Mention any one action
Question: Mention any one action that you have undertaken to conserve trees. Solution: I take part in various afforestation programmes where I also spread awareness about individual measures that can be taken by people for conservation of trees such as recycling paper, planting a tree on special occasions, etc....
Read More →Find the sum of the series:
Question: Find the sum of the series: $(1 \times 2 \times 4)+(2 \times 3 \times 7)+(3 \times 4 \times 10)+\ldots$ to $n$ terms Solution: In the given question we need to find the sum of the series. For that, first, we need to find the $\mathrm{n}^{\text {th }}$ term of the series so that we can use summation of the series with standard identities and get the required sum. The series given is $(1 \times 2 \times 4)+(2 \times 3 \times 7)+(3 \times 4 \times 10)+\ldots$ to $n$ terms. The series can ...
Read More →Why is it important to conserve
Question: Why is it important to conserve forests? Solution: It is important to conserve forests because forests: 1. maintain the level of C02 in atmosphere. 2. bind the top layer of soil that increases its fertility. 3. help in absorbing rain water and thus, preventing floods. 4. maintain the water cycle. 5.serve as natural habitat of various species....
Read More →In our country, large patches
Question: In our country, large patches of forests are being cleared for cultivation of crops. The environmental impact of such a practice will lead to : (a) soil erosion (b) soil pollution (c) soil conservation (d) soil fertility Solution: (a) Soil erosion will be the environmental impact of clearing larger patches of forests (deforestation). When trees are cut down, then there are no roots to bind the soil particles and prevent them from being carried away by strong wind or water. This removal...
Read More →If the radius of a sphere is measured as 9 cm with an error of 0.03 m,
Question: If the radius of a sphere is measured as 9 cm with an error of 0.03 m, find the approximate error in calculating its surface area. Solution: Letxbe the radius andybe the surface area of the sphere. Then, $x=9$ $\Delta x=0.03 \mathrm{~m}=3 \mathrm{~cm}$ $\Rightarrow x+\Delta x=9+3=12 \mathrm{~cm}$ $y=4 \pi \mathrm{x}^{2}$ For $\mathrm{x}=9$ $\mathrm{y}=4 \pi \times 9^{2}=324 \pi$ $\frac{\mathrm{dy}}{\mathrm{dx}}=8 \pi \mathrm{x}$ $\Rightarrow\left(\frac{\mathrm{dy}}{\mathrm{dx}}\right)_...
Read More →Migratory birds fly to far away areas during
Question: Migratory birds fly to far away areas during a particular time of a year. Which of the following conditions present in their habitat during that time are responsible for this behaviour? (i) Unavailability of food. (ii) Extreme weather conditions. (iii) Over crowding. (iv) Lack of nesting areas. (a) (ii) and (iii) (b) (i) and (ii) (c) (i) and (iv) (d) (ii) and (iv) Solution: (d) The process of a bird moving from one place to another due to the climatic changes is called migration. It is...
Read More →The Red Data Book keeps a record of all the
Question: The Red Data Book keeps a record of all the (i) endemic species (ii) extinct species (iii) endangered plants (iv) endangered animals (a) (i) and (ii) (b) (ii) and (iii) (c) (iii) and (iv) (d) (i) and (iv) Solution: (c) Red Data Book is the source book which keeps a record of all the endangered animals and plants. There are different Red Data Books for plants, animals and other species....
Read More →What do blackbuck, elephant, python
Question: What do blackbuck, elephant, python and golden cat together represent in a forest? (a) Fauna (b) Ecosystem (c) Flora (d) Species Solution: (a) Blackbuck, elephant, python and golden at together represent fauna in a forest. The animals of particular area called fauna of that area.Flora is the plants of a particular area. Ecosystem includes all the living organisms of an area and their physical environment. Species is a group of population which are capable of interbreeding....
Read More →Which statement is incorrect
Question: Which statement is incorrect about endangered species? (a) Their number has decreased drastically (b) They might become extinct in the near future (c) They pose a danger to other animals (d) Their natural habitat needs to be protected Solution: (c) The species which are facing the risk of extinction due to their diminishing numbers : are called endangered species. An animal species become endangered due to: (i) they are few in number. (ii) they are being killed by predators. (iii) hunt...
Read More →Which of the following feature
Question: Which of the following feature is correct for a wildlife sanctuary? (a) It is an artificially created area for animals protection (b) It is a protected area for threatened and endangered wild animals (c) It is meant for conservation of only plant species (d) Capturing and poaching of anjmals is strictly prohibited here Solution: (a) A wildlife sanctuary is a protected area, which is artificially created for the protection of wild animals in their natural habitat. Killing (poaching) or ...
Read More →Find the sum of the series:
Question: Find the sum of the series: $(1 \times 2 \times 3)+(2 \times 3 \times 4)+(3 \times 4 \times 5)+\ldots$ to $n$ terms Solution: In the given question we need to find the sum of the series. For that, first, we need to find the $\mathrm{n}^{\text {th }}$ term of the series so that we can use summation of the series with standard identities and get the required sum. The series given is $(1 \times 2 \times 3)+(2 \times 3 \times 4)+(3 \times 4 \times 5)+\ldots$ to $n$ terms. The series can be...
Read More →Which one of the following statement
Question: Which one of the following statement is true about endemic species? (a) They are found exclusively in a specific habitat (b) Endemic species can never become endangered (c) They are found only in zoos and botanical gardens (d) They are not affected by the destruction of their habitat Solution: (a) Endemic species are those species of plants and animals which are found exclusively in a specific habitat. e.g. Sal and wild mango are endemic plants of Pachmarhi Biosphere Reserve. Their exi...
Read More →Find the approximate value of log10 1005, given that log10 e = 0.4343.
Question: Find the approximate value of log101005, given that log10e= 0.4343. Solution: Let: $y=f(x)=\log _{10} x$ Here, $x=1000$ $x+\Delta x=1005$ $\Rightarrow \Delta x=5$ $\Rightarrow d x=\Delta x=5$ For $x=1000$ $y=\log _{10} 1000=\log _{10}(10)^{3}=3$ Now, $y=\log _{10} x=\frac{\log _{e} x}{\log _{e} 10}$ $\therefore \frac{d y}{d x}=\frac{0.4343}{x}$ $\Rightarrow\left(\frac{d y}{d x}\right)_{x=1000}=\frac{0.4343}{1000}=0.0004343$ $\Delta y=d y=\frac{d y}{d x} d x=0.0004343 \times 5=0.0021715...
Read More →The places meant for conservation
Question: The places meant for conservation of biodiversity in their natural habitat are (i) Zoological garden (ii) Botanical garden (iii) Wildlife sanctuary (iv) National park (a) (i) and (ii) (b) (ii) and (iii) (c) (iii) and (iv) (d) (i) and (iv) Solution: (c) Wildlife sanctuary, national parks are in situ conservation methods of biodiversity. These places are meant for conservation of species in their natural habitat. The other options, i.e. zoological and botanical gardens are ex situ conser...
Read More →Which one of the following statements
Question: Which one of the following statements is true about a Biosphere Reserve? (a) It is a protected area where only endemic species live (b) It is meant only for the conservation of plants and animals (c) It is meant to conserve both, the biodiversity and the culture of that area (d) There are no other protected areas within its limits Solution: (c) A Biosphere Reserve is large, protected area of land meant for the conservation of wildlife, biodiversity and the traditional lifestyle of trib...
Read More →Which one of the following changes
Question: Which one of the following changes may occur due to desertification? (a) Decrease in atmospheric temperature (b) Increase in water holding capacity of soil (c) Increased chances of floods (d) Conversion of fertile land into a desert Solution: (d) The process by vhich fertile land becomes desert is called desertification. It takes place due to the deforestation. When forest trees are cut, there will be no roots to bind the soil particles together and prevent them from carrying away. Thu...
Read More →Which one of the following changes
Question: Which one of the following changes may occur due to desertification? (a) Decrease in atmospheric temperature (b) Increase in water holding capacity of soil (c) Increased chances of floods (d) Conversion of fertile land into a desert Solution: (d) The process by vhich fertile land becomes desert is called desertification. It takes place due to the deforestation. When forest trees are cut, there will be no roots to bind the soil particles together and prevent them from carrying away. Thu...
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