MCQ Questions Chapter 15 Our Environment Class 10 Science

Please refer to MCQ Questions Chapter 15 Our Environment Class 10 Social Science with answers provided below. These multiple-choice questions have been developed based on the latest NCERT book for class 10 Social Science issued for the current academic year. We have provided MCQ Questions for Class 10 Social Science for all chapters on our website. Students should learn the objective based questions for Chapter 15 Our Environment in Class 10 Social Science provided below to get more marks in exams.

Chapter 15 Our Environment MCQ Questions

Please refer to the following Chapter 15 Our Environment MCQ Questions Class 10 Social Science with solutions for all important topics in the chapter.

MCQ Questions Answers for Chapter 15 Our Environment Class 10 Social Science

Question: The existence of decomposers is essential in the biosphere because
(a) Replenishment of nutrients in the soil naturally
(b) Helps in removing the biodegradable wastes from the environment
(c) Helps in breaking complex organic matter into simpler inorganic matter
(d) all of the above   

Question. Choose the incorrect statement from the following:
(a) Ozone is a molecule formed by three atoms of oxygen.
(b) Ozone shields the surface of the Earth from ultraviolet radiations.
(c) Ozone is deadly poisonous.
(d) Ozone gets decomposed by UV radiations.

Question. In a food chain, the third trophic level is always occupied by
(a) carnivores
(b) herbivores
(c) decomposers
(d) producers

Question. An ecosystem includes
(a) all living organisms
(b) non-living objects
(c) both living organisms and non-living objects
(d) sometimes living organisms and sometimes non-living objects

Question. In the given food chain, suppose the amount of energy at fourth trophic level is 5 kJ, what will be the energy available at the producer level?
Grass → Grasshopper → Frog → Snake → Hawk
(a) 5 kJ
(b) 50 kJ
(c) 500 kJ
(d) 5000 kJ

Question. In an ecosystem, 10% of energy available for transfer from one trophic level to the next is in the form of:
(a) heat energy
(b) chemical energy
(c) mechanical energy
(d) light energy 

Question. Which of the following are water intensive crops?
(a) Wheat are rice
(b) Wheat and sugarcane
(c) Sugarcane and rice
(d) Wheat and gram 

Question. How much of the net primary productivity of a terrestrial ecosystem is eaten and digested by herbivores?
(a) 100%
(b) 10%
(c) 1%
(d) 0.1%

Question. Which one of the following is an artificial ecosystem?
(a) Pond
(b) Crop field
(c) Lake
(d) Forest

Question. Excessive exposure of humans to UV-rays results in
(i) damage to immune system (ii) damage to lungs
(iii) skin cancer (iv) peptic ulcers
(a) (i) and (ii)
(b) (ii) and (iv)
(c) (i) and (iii)
(d) (iii) and (iv)

Question. The decomposers in an ecosystem
(a) convert inorganic material, to simpler forms
(b) convert organic material to inorganic forms
(c) convert inorganic materials into organic compounds
(d) do not breakdown organic compounds

Question. Depletion of ozone is mainly due to
(a) chlorofluorocarbons
(b) carbon monoxide
(c) methane
(d) pesticides

Question. The most poisonous product formed by incomplete combustion of fossil fuels is
(a) Carbon dioxide
(b) Nitrogen dioxide
(c) Carbon monoxide
(d) Sulphur dioxide 

Question. Food web is constituted by
(a) relationship between the organisms and the environment.
(b) relationship between plants and animals.
(c) various interlinked food chains in an ecosystem.
(d) relationship between animals and environment. 

Question: The chemical which is mainly responsible for the depletion of ozone layer
(a) AFC
(b) H₂S
(c) CFC
(d) CCl₄   

Question: Which of the following limits the number of trophic levels in a food chain
(a) decrease in energy at higher trophic levels
(b) Deficiency of food supply
(c) supply of chemicals
(d) availability of solar input   

Question: The component that is required for the conversion of O₂ into O₃
(a) X – rays
(b) UV –rays
(c) infra – red rays
(d) α – rays   

Question: Why do we see greater number of individuals at the lower trophic level?
(a) Because they are plant eaters
(b) because they are Producers
(c) because they are carnivores
(d) because they are decomposers   

Question: The decomposers in an ecosystem
(a) Convert solar energy in to chemical energy
(b) Produce their own food
(c) convert complex organic compounds into simple inorganic compounds
(d) Convert simple inorganic compounds into complex organic compound 

Question: An aquarium need to be cleaned frequently but a pond need not be cleaned
(a) because pond has decomposers in it so it will be cleaned naturally
(b) because there is a pond cleaner in it
(c) Because it is exposed sun light
(d) Because of rich iodine content     

Question. In an ecosystem , 10 % 0f energy available for transfer from one trophic level to the net is in the form of   
(a) Heat energy
(b) Light energy
(c) Chemical energy
(d) mechanical energy

Question. Bio degradable wastes can be decomposed by decomposers because         
(a) they use enzymes for their life processes
(b) they use hormones for their life processes
(c) they use oxygen for their life processes
(d) They do not use enzymes for their life processes

Question. The decomposers in an ecosystem       
(a) Convert solar energy in to chemical energy
(b) Produce their own food
(c) convert complex organic compounds into simple inorganic compounds
(d) Convert simple inorganic compounds into complex organic compound

Question. The consequences of ozone depletion are           
(a) Greenhouse effect and global warming
(b) Cataract and skin cancer
(c) Bio magnification and eutrophication
(d) acid rain fall and pollution

Question. The percentage of solar radiation absorb by all the green plants for the process of     
(a) 10 %
(b) 100%
(c) 9%
(d) 1 %

Question. In a food chain , the first trophic level is always occupied by   
(a) Carnivores
(b) Detritivores
(c) Herbivores
(d) Producers

Question. The existence of decomposers is essential in the biosphere because       
(a) Replenishment of nutrients in the soil naturally
(b) Helps in removing the biodegradable wastes from the environment
(c) Helps in breaking complex organic matter into simpler inorganic matter
(d) all of the above

Question. Which of the following limits the number of trophic levels in a food chain       
(a) decrease in energy at higher trophic levels
(b) Deficiency of food supply
(c) supply of chemicals
(d) availability of solar input

Question. Which two of the following statements regarding food chains are correct?   
(i) Removal of 80% tigers resulted in increased growth of vegetation.
(ii) Removal of most carnivores resulted in increased population of deer.
(iii) Length of food chain is limited to 3 – 4 trophic levels due to energy loss.
(iv) Length of food chain may vary from 2 – 3 trophic levels.
(a) (i) and (iv)
(b) (i) and (ii)
(c) (ii) and (iii)
(d) (iii) and (iv)

Question. Match the terms given in column-I with their definition given in column-II and choose the correct option.   

Column – I	Column – II
A. Food chain	I. An organism that eats meat.
B. Food web	II. An organism that eats plants.
C. Heterotrophs	III. An organism that makes its food from light or chemical energy.
D. Autotrophs	IV. An organism that gets its energy by eating other organisms.
E. Carnivore	V. The sequence of organisms of who eats whom in a biological community.
F. Herbivore	VI. The network of all the interrelated food chains in a biological community.

(a) A – V; B – VI; C – IV; D – III; E – I; F – II
(b) A – VI; B – IV; C – III; D – I; E – II; F – V
(c) A – III; B – I; C – II; D – V; E – VI; F – IV
(d) A – II, B – V; C – VI; D – IV; E – III; F – I

Question. If a grasshopper is eaten by a frog, then the energy transfer will be from           
(a) producer to decomposer
(b) producer to primary consumer
(c) primary consumer to secondary consumer
(d) secondary consumer to primary consumer

Question. Which of the following constitute a food-chain?   
(a) Grass, wheat and mango
(b) Grass, goat and human
(c) Goat, cow and elephant
(d) Grass, fish and goat

Question. Prolonged exposure to the fumes released by incomplete combustion of coal may cause death of a human because of   
(a) inhalation of unburnt carbon particles.
(b) continuous exposure to high temperature.
(c) increased level of carbon monoxide.
(d) increased level of carbon dioxide.

Question. Which of the following ecological pyramid is never inverted?     
(a) Pyramid of number in forest ecosystem
(b) Pyramid of biomass in pond ecosystem
(c) Pyramid of energy in parasitic food chain
(d) Pyramid of biomass in parasitic food chain

Question. Which among grass, goat, tiger and vulture in a food chain, will have the maximum concentration of harmful chemicals in its body due to contamination of pesticides in the soil? 
(a) Grass since it grows in the contaminated soil
(b) Goat since it eats the grass
(c) Tiger since it feeds on the goat which feeds on the grass
(d) Vulture since it eats the tiger, which in turn eats the goat, which eats the grass

Question. Which of the following groups contain only biodegradable items ?     
(a) Grass, flowers and leather
(b) Grass, wood and plastic
(c) Fruit-peels, cake and lime-juice
(d) Cake, wood and grass

Question. Which of the following is an result of biological magnification?   
(a) Top level predators may be harmed by toxic chemicals in environment.
(b) Increase in carbon dioxide
(c) The green-house effect will be most significance at the poles
(d) Energy is lost at each trophic level of a food chain

Question. The diagram below shows a food pyramid.   

Which level of the food pyramid contains consumers with the least biomass?
(a) snakes
(b) frogs
(c) crickets
(d) green plants

Question. Match column – I with column – II and select the correct answer using the codes given below.   
Column – I              Column – II
A. Phosphorus       I. Atmosphere
B. Carbon             II. Producers
C. Goat                III. Rock
D. Grasses            IV. T2
(a) A – III; B – II; C – IV; D – I
(b) A – III; B – I; C – IV; D – II
(c) A – I; B – III; C – II; D – IV
(d) A – II; B – III; C – IV; D – I

Question. The component that is required for the conversion of O₂ into O₃         
(a) X – rays
(b) UV –rays
(c) infra – red rays
(d) α – rays

Question. Which is the pond ecosystem?     
(a) Phytoplankton → Zooplankton → Snail → Fish → King → Fisher
(b) Phytoplankton → Snail → Zooplankton → Fish →King → Fisher
(c) Plants → Fish → King → Fisher
(d) Plants → King → Fisher → Fish

Question. An aquarium need to be cleaned frequently but a pond need not be cleaned       
(a) because pond has decomposers in it so it will be cleaned naturally
(b) because there is a pond cleaner in it
(c) Because it is exposed sun light
(d) Because of rich iodine content

Question. The accumulation of chemicals at various trophic levels in a food chain is known as     
(a) Chemical magnification
(b) Physical magnification
(c) bio magnification
(d) Eutrophication

Question.

In the above pyramid tigers occupy     
(a) Producers
(b) Primary consumer
(c) Secondary consumer
(d) Tertiary consumer

Question. The limitation of number of trophic levels in a food chain is due to     
(a) Sufficient food supply
(b) decrease in energy level at higher trophic level
(c) Increase in energy level at higher trophic level
(d) supply of water

Question. Depletion of oxygen in the water is called             
(a) Photosynthesis
(b) Respiration
(c) Eutrophication
(d) Bio magnification

Question. Identify the biotic factors of an ecosystem from the following     
(a) Temperature , rain fall , soil
(b) Plants , animals and microorganisms
(c) Temperature , microbes and rainfall
(d) plants , animals and soil

Question. Why do we see greater number of individuals at the lower trophic level?       
(a) Because they are plant eaters
(b) because they are Producers
(c) because they are carnivores
(d) because they are decomposers

Question. What will happen if frog is missing in the food chain given below?     
Grass → Grass → hopper → Frog → Snake
(a) population of grass increases and grass hopper decreases
(b) Population of snake increases and grass hopper decreases
(c) Population of grass hopper increases and population of snake decreases
(d) population of grass hopper decreases and snake increases

Question. From the given diagram state which statement is TRUE.   

(a) Picture A represents food web
(b) Picture B represents food chain
(c) Picture A represents pond ecosystem
(d) Picture A represents Food chain and Picture B represents Food web respectively

Question. One organism may be the food for many organism will constitute the     
(a) Food chain
(b) Food web
(c) food pyramid
(d) food trophic level

Question: Minimata a disease caused due to
(a) land pollution
(b) Air pollution
(c) Bio magnification
(d) water pollution     

Question: The element which is highly responsible for destruction of ozone molecule is
(a) Fluorine
(b) Chlorine
(c) Methane
(d) Carbon   

Question: The consequences of ozone depletion are
(a) Greenhouse effect and global warming
(b) Cataract and skin cancer
(c) Bio magnification and eutrophication
(d) acid rain fall and pollution   

Question: Depletion of oxygen in the water is called
(a) Photosynthesis
(b) Respiration
(c) Eutrophication
(d) Bio magnification 

Question: Non-biodegradable wastes can be disposed by
(a) Decomposition
(b) throwing into water bodies
(c) buried under the soil
(d) Incineration   

Question: Bio degradable wastes can be decomposed by decomposers because
(a) they use enzymes for their life processes
(b) they use hormones for their life processes
(c) they use oxygen for their life processes
(d) They do not use enzymes for their life processes

True Or False :

Question. Specific enzymes are needed for the break-down of a particular substance.

Question. Organisms can make organic compounds from inorganic substances by using the radiant energy of the sun in the presence of chlorophyll.

Question. Non-biodegradable articles are the ones which cannot be digested. 

Question. The materials like plastics are not acted upon by physical process.

Question. The amount of usable energy remains constant as it is passed from one trophic level to another.

Assertion-reason type Questions :

For question numbers 2 two statements are given-one labeled as Assertion (A) and the other labeled
Reason (R). Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below:
(a) Both ‘A’ and ‘R’ are true and ‘R’ is correct explanation of the Assertion.
(b) Both ‘A’ and ‘R’ are true but ‘R’ is not correct explanation of the Assertion.
(c) ‘A’ is true but ‘R’ is false.
(d) ‘A’ is false but ‘R’ is true.

Question. Assertion: Ozone is formed in upper atmosphere by O2 in presence of UV radiations.
Reason: Ozone depletion will lead to UV rays reaching earth which may cause skin cancer.

Question. Assertion: Polythene bags and plastic containers are non-biodegradable substances.
Reason: They can be broken down by microorganisms in natural simple harmless substances.

For question numbers 2 two statements are given-one labeled as Assertion (A) and the other labeled
Reason (R). Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below:
(a) Both ‘A’ and ‘R’ are true and ‘R’ is correct explanation of the Assertion.
(b) Both ‘A’ and ‘R’ are true but ‘R’ is not correct explanation of the Assertion.
(c) ‘A’ is true but ‘R’ is false.
(d) ‘A’ is false but ‘R’ is true.

Question. Assertion: Aquarium needs regular cleaning
Reason: There are no microbes to clean water in aquarium, therefore, it needs to be regularly cleaned.

Question. Assertion: The concentration of harmful chemicals is least in human beings.
Reason: Man is at the apex of the food chain.

(a) If both Assertion and Reason are correct and Reason is the correct explanation of Assertion.
(b) If both Assertion and Reason are correct, but Reason is not the correct explanation of Assertion.
(c) If Assertion is correct but Reason is incorrect.
(d) If Assertion is incorrect but Reason is correct.

Question. Assertion: Abiotic component of an ecosystem involves cycling of material and flow of energy. 
Reason: This is essential to keep biotic factors alive.

Question. Assertion: Supersonic jets cause pollution as they thin out ozone. 
Reason: Depletion of ozone cause green house effect.

Question. Assertion: The crown fires are most destructive as they burn the tree top. 
Reason: Due to crown fire, the temperature of that area may rise upto 700°C.

Question. Assertion: Animals adopt different strategies to survive in hostile environment. 
Reason: Praying mantis is green in colour which merges with plant foliage.

Question. Assertion: Trophic levels are formed by only plants.   
Reason: Food chains and webs are formed due to linked organisms on the basis of their nutrition.

Question. Assertion: In an ecosystem, the function of producers is to convert organic compounds into inorganic compounds. 
Reason: Green plants, the producers, transduce solar energy.

Question. Assertion: Tropical rain forests are disappearing fast from developing countries such as India.   
Reason: No value is attached to these forests because these are poor in biodiversity.

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