MCQs For NCERT Class 10 Science Chapter 15 Our Environment

Please refer to the MCQ Questions for Class 10 Science Chapter 15 Our Environment with Answers. The following Our Environment Class 10 Science MCQ Questions have been designed based on the current academic year syllabus and examination guidelines for Class 10. Our faculty has designed MCQ Questions for Class 10 Science with Answers for all chapters as per your NCERT Class 10 Science book.

Our Environment Class 10 MCQ Questions with Answers

Please see below Our Environment Class 10 Science MCQ Questions, solve the questions and compare your answers with the solutions provided below.

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

Question. Disposable plastic plates should not be used because:   
(a) they are made of materials with light weight
(b) they are made of toxic materials
(c) they are made of biodegradable materials
(d) they are made of non-biodegradable materials

Question. Which of the follwoing are environment friendly practices?   
(a) Carrying cloth-bags to put purchases in while shopping.
(b) Switching off unncessary lights and fans.
(c) Walking to school instead of getting your mother to drop you on her scooter.
(d) All of the above

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

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 the given figure, the various trophic levels are shown in a pyramid. At which trophic level is maximum energy available? 
(a) T4
(b) T2
(c) T1
(d) T3

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

Question. Expand the abbreviation GAP:     
(a) Governmental Agency for Pollution Control
(b) Gross Assimilation by Photosynthesis
(c) Ganga Action Plan
(d) Governmental Agency for Animal Protection

Question. The flow of energy in an ecosystem is always: 
(a) unidirectional
(b) bidirectional
(c) multidirectional
(d) no specific direction

Question. Which of the following are biodegradable substances?   
(a) Glass bottole, Grass
(b) Jutebag, polythene bag
(c) Cotton cloth, vegetable peels
(d) DDT, Pen refill

Question. In the following groups of materials, which group(s) contain(s) only non-biodegradable items?                 
(i) Wood, paper, leather
(ii) Polythene, detergent, PVC
(iii) Plastic, detergent, grass
(iv) Plastic, Bakelite, DDT
(a) (i)
(b) (ii)
(c) (i) and (ii)
(d) (ii) and (iv)

Question. Which of the statement is incorrect?   
(a) Producers form the first prophic level.
(b) Produces trap solor energy and transform it into chemical energy in food.
(c) All plants are producers.
(d) Nutrients and energy enter the living world through producers.

Question. Which of the following limits the number of trophic levels in a food chain?     
(a) Decrease in energy at higher trophic levels
(b) Deficient food supply
(c) Polluted air
(d) Water

Question. The percentage of solar radiation absorbed by all the green plants for the process of photosynthesis is about:   
(a) 1%
(b) 5%
(c) 8%
(d) 10%

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. It was found that water from a river was contaminated with Coliform bacteria. Which one of the following pollutant might have got mixed with the water? 
(a) Fertilizer run off
(b) Industrial waste
(c) Pesticides
(d) Human faecal matter

Question: Which of the following does not form part of particulate matter?
(a) Dust
(b) Fly ash
(c) Aerosols
(d) Nitric oxide   

Question: Habitat together with functions of species constitute:
(a) Trophic level
(b) Boundary
(c) Topography
(d) Niche 

Question: Plants are killed in winter by frost:
(a) Because of dessication and mechanical damage to the tissue.
(b) Because no photosynthesis take place at such a low temperature.
(c) Because respiration ceases at such low temperature.
(d) Because there is no transpiration. 

Question: An example of a producer in the aquatic food web would be:
(a) Duckweed
(b) Ducks
(c) Fish
(d) Insects   

Question: Which one is recyclable waste?
(a) Paper
(b) Torn clothes
(c) Metallic and plastic discards
(d) All the above 

Question: In order to maintain proper ecological balance
(a) the existing forests would be cleared and new ones should be planted.
(b) some quick growing annuals should be planted if a tree must be cut for other uses.
(c) tree must be cut whenever necessary because the underground part performs the useful purpose.
(d) a tree should be planted in place of one to be cut.   

Question: It is said, the Tajmahal may be destroyed due to
(a) Flood in Yamuna river
(b) Decomposition of marble as a result of high temperature
(c) Air pollutants released from oil refinery of Mathura
(d) All the above   

Question: Which of the following are environment-friendly practices?
(a) Carrying cloth-bags to put purchases in while shopping
(b) Switching off unnecessary lights and fans
(c) Walking to school instead of getting your mother to drop you on her scooter
(d) All of the above   

Question: Free services provided to humans by ecosystems include
(a) control of atmospheric carbon dioxide concentration.
(b) prevention of soil erosion.
(c) filtering of pollutants from water and air.
(d) all of the above 

Question: Each step in a food chain is called a
(a) trophic level.
(b) consumer level.
(c) food web. 
(d) producer. 

Question: Carcinogenic chemicals produced during recycling of plastics and polythene is/are
(a) formaldehyde
(b) polycyclic aromatic compounds
(c) vinyl chloride
(d) dioxins and furans 

Question: Organisms of a higher trophic level which feed on several types of organisms belonging to a lower trophic level constitute the
(a) food web
(b) ecological pyramid
(c) ecosystem
(d) food chain 

Question: Several factories were pouring their wastes in rivers A and B. Water samples were collected from these two rivers. It was observed that sample collected from river A was acidic while that of river B was basic. The factories located near A and B are :
(a) Soaps and detergents factories near A and alcohol distillery near B.
(b) Soaps and detergents factories near B and alcohol distillery near A.
(c) Lead storage battery manufacturing factories near A and soaps and detergents factories near B.
(d) Lead storage bettery manufacturing factories near B and soaps and detergents factories near A.
Answer : (c) Lead storage battery manufacturing factories near A and soaps and detergents factories near B.

Question: The % of solar radiation absorbed by all the green plants for the process of photosynthesis is about
(a) 1%
(b) 5%
(c) 8%
(d) 10%
Answer : (a) 1%

Question: What will happen if dear is missing in the food chain given below ?
Grass → Dear → Tiger
(a) The population of tiger increases
(b) Tiger will start eating grass
(c) The population of grass decreases
(d) The population of tiger decreases and the population of grass increases
Answer : (d) The population of tiger decreases and the population of grass increases

Question: Disposable plastic plates should not be used because :
(a) They are made of materials with light weight.
(b) They are made of toxic materials.
(c) They are made of biodegradable materials.
(d) They are made of non-biodegradable materials.
Answer : (d) They are made of non-biodegradable materials.

Question: Which of the following statement is incorrect ?
(a) All green plants and blue green algae are producers.
(b) Green plants get their food from organic compounds.
(c) Producers prepare their own food from inorganic compounds.
(d) Plants convert solar energy into chemical energy.
Answer : (b) Green plants get their food from organic compounds.

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
Answer : (b) Grass, goat and human

Question: In an ecosystem, the function of the producers is to
(a) convert organic compounds into inorganic compounds.
(b) trap solar energy and convert it into chemical energy.
(c) utilize chemical energy.
(d) release energy.   

Question: Why do scientists think that human-induced global warming will be more harmful to plants and animals than were past, natural climate fluctuations ?
(a) Because temperatures will change faster
(b) Because the temperature changes will be larger
(c) Because species now are less adaptable than species in the past
(d) Because ecosystems are now more complicated than
they used to be 

Question: A decrease in the grass population will most immediately decrease the available energy for the
(a) mouse
(b) snake
(c) hawk
(d) frog 

Question: The last chain of food is
(a) producers
(b) decomposers
(c) parasites
(d) none of these 

Question: As a biologist, if you become very interested in the study of the interaction of organisms with each other and the environment your subspeciality would be
(a) Zoology
(b) Ecology
(c) Botany
(d) Herpetology   

Question: The part of earth comprising water is called an
(a) atmosphere
(b) hydrosphere
(c) lithosphere 
(d) none of the above

Question: Trophic levels are formed by –
(a) only plants
(b) only animals
(c) only carnivores
(d) organisms linked in food chain 

Question: The maximum energy is stored at following tropical level in any ecosystem
(a) Producers
(b) Herbivores
(c) Carnivores
(d) Top carnivo 

Question. The accumulation of non-biodegradable pesti- cides in the food chain in increasing amount at each higher trophic level is known as:         
(a) eutrophication
(b) pollution
(c) bio-magnification
(d) accumulation

Fill in the blanks

Question. In nature, all green plants are …………………………. whereas animals are consumer.

Question. Decomposer organisms are …………………………. in their action.

Question. A series of organisms, each of which feeds on the next organism, the beginning of which is a green plant, is called a …………………….

True Or False :

Question. Ecology is the scientific study of the interaction of organisms with each other and the environment. 

Question. Blue green algae are producers. 

Question. The energy within an ecosystem is fixed and never changes. 

Question. The reproduction and other activities of living organisms are affected by the abiotic components of ecosystem.

Question. Ozone is formed in stratosphere by action of ultraviolet radiations on oxygen. 

Question. The abiotic components of the environment are the living factors.

Match the column :

Question.

Column I	Column II
(A) Grass	(p) Primary carnivore
(B) Grasshopper	(q) Secondary carnivore
(C) Frog	(r) Producer
(D) Hawk	(s) Primary consumer

Question.

Column A	Column B
(A) Third trophic level	(p) Ozone
(B) Accumulation of pesticides at higher trophic level	(q) CFCs
(C) Green plants	(r) Herbivore
(D) Flow of energy in an ecosystem	(s) Biomagnification
(E) Consists of 3 atoms of oxygen	(t) Decomposers
(F) Main cause of depletion of ozone layer	(u) Producers
(G) Second trophic level	(v) Unidirectional
(H) Break-down of dead organic compounds	(w) Carnivores

Assertion and Reasoning Based Questions

Directions : In the following questions, a statement of assertion is followed by a statement of reason. Mark the correct choice as :
(a) If both assertion and reason are true and reason is the correct explanation of assertion.
(b) If both assertion and reason are true, but reason is not the correct explanation of assertion.
(c) If assertion is true, but reason is false.
(d) If assertion is false but reason is true.

Question. Assertion : Energy available at each trophic level gets diminished progressively.
Reason : Little usable energy remains after four trophic levels.
Answer : (c) The energy available at each trophic level gets diminished progressively due to loss of energy at each level. Thus assertion is true, but reason is false.

Question. Assertion : Arctic’s ozone depletion tends to be milder and short lived than the Antarctic’s.
Reason : CFCs, frigid temperatures and sunlight are not present at the Arctic at the same time.
Answer : (a) It is necessary to have all three at the same time for ozone layer to deplete. Thus both assertion and reason are true and reason is the correct explanation of the assertion.

Question. Assertion : Plastics are non- biodegradable.
Reason : Enzymes cannot degrade plastics.
Answer : (a) Substances which cannot be decomposed by the action of microorganisms are known as nonbiodegradable.
Mircroorganisms release enzymes which decompose the materials but these enzymes are specific in their action that’s why enzymes cannot decompose all the materials. Thus both assertion and reason are true and reason is the correct explanation of the assertion.

Question. Assertion : Chemicals and toxins accumulate more and more as you move up the food chain.
Reason : Anything that gets into biological tissue, that is not normally there, has the potential to accumulate and magnify.
Answer : (a) Biomagnification, is the increase in concentration of toxins up the food chain. Chemicals and toxins accumulate more and more as we move up the food chain, because they do not get broken down in the body. Anything that gets into biological tissue, that is not normally there, has the potential to accumulate and magnify as it moves up the food chain. Thus both assertion and reason are true and reason is the correct explanation of the assertion.

Question. Assertion : The flow of energy is unidirectional.
Reason : Energy as it progresses through the various trophic levels it is no longer available to the previous level.
Answer : (a) The flow of energy is unidirectional. The energy that is captured by the autotroph does not revert back to the solar input and the energy which passes to the herbivores does not come back to autotroph. As it moves progressively through the various trophic levels it is no longer available to the previous level. Moreover, the energy available at each trophic level gets diminished progressively due to loss of energy at each level. Thus both assertion and reason are true And reason is the correct explanation of the assertion.

Creating Based Questions

Question. The amount of ozone in the atmosphere began to drop sharply in the 1980s. This decrease has been linked to synthetic chemicals like chlorofluorocarbons (CFCs) which are used as refrigerants and in fire extinguishers.
In 1987, the United Nations Environment Programme (UNEP) succeeded in forging an agreement to freeze CFC production at 1986 levels. It is now mandatory for all the manufacturing companies to make CFC free refrigerators throughout the world. Suggest an alternative coolant that can be used.
Answer : HFCs have replaced CFCs and HCFCs as coolant for refrigerators. HFCs pose no harm to the ozone layer.
They are potent green house gases. HFCs are generated during the manufacturing of HCFCs.

Question. Using the following information, form a pathway which shows the flow of energy at each trophic level.
And also include information that is not mentioned below to complete it. light energy, organic products, first trophic level, herbivores, second trophic level, energy. 
Answer : Light energy green surfaces of plants → chemical energy stored in various → organic products in the plants first trophic level herbivores consume → plants
as → food second trophic level convert chemical energy into kinetic energy herbivores → are consumed by carnivores of the first order → (secondary consumers) third → trophic level → primary carnivores are consumed by → top carnivores (last level) energy will be degraded.

Question. Rita wants to have an aquarium at home. What are the things that she needs to keep in mind in designing an aquarium ?
Answer : The fish would need a free space for swimming, water, oxygen and food. Thus, she need a good aquarium tank, oxygen can be provided through an oxygen pump (aerator) and fish food is available in the market. Water parameters for nitrate, nitrite, ammonia and pH levels are to be maintained. To condition water properly, use a de-chlorinating and biological aquarium supplement. It is recommended to change 25 percent of the aquarium water at least once a month. This will help maintain a clean and healthy tank, plus it keeps nitrate concentrations at a safe level. Overcrowding can lead to low oxygen levels in the water. Another crisis of overcrowding includes excess waste, which clogs the filter and degrades the aquarium water.

Question. Using the following information form a pathway showing the formation of ozone at higher levels. And also include information that is not mentioned below to complete it.
Ozone, UV, Molecular oxygen.
Answer : Ozone production → UV radiation acting on oxygen (O₂) molecule → the higher energy UV radiation split apart some molecular oxygen (O₂) →

free oxygen (O) atoms then → combine with molecular oxygen ozone O + O₂ → O₃. (Ozone)

Question. Shyam was very upset after reading the news of a whale shark that was found dead in waters off the TanjungAru beach in Menumbok. Postmortem results showed the shark had died of starvation and indigestion as it had a huge plastic bag stuck in its stomach. Suggest some measures that can be taken to reduce plastic waste.
Answer : Cloth bags can be used instead of using plastic bags as they are washable, strong and more durable than plastic bags. They are made of biodegradable material and do not pollute the environment. They can be recycled and reused and are capable of carrying more things.
These days, new types of plastics which are said to be biodegradable, are available.

Paragraph/Table and Case Study Based Questions

1. Read the following and answer any four questions from 1(i) to 1(v):
The energy flow in the ecosystem is one of the major factors that support the survival of such a great number of organisms. For almost all organisms on earth, the primary source of energy is solar energy. It is amusing to find that we receive less than 50 per cent of the sun’s effective radiation on earth. When we say effective radiation, we mean the radiation, which can be used by plants to carry out photosynthesis.

Question. If 100 J energy is available at the producer level in a food chain then the energy available to the secondary consumer will be:
(a) 10 J
(b) 0.1 J
(c) 1 J
(d) 0.01 J

Question. Green plants utilise …………… percent of sun’s energy to prepare their food by the process of photosynthesis.
(a) 1 percent
(b) 10 percent
(c) 20 percent
(d) 99 percent

Question. Which of the two sets belong to the same trophic level?
(a) Frog: Lizard
(b) Rabbit: Tiger
(c) Vulture: crow
(d) Deer: Hawk

Question. The ____________ is the functional unit of environment.
(a) Genus
(b) Ecosystem
(c) Class
(d) Biome

Question. A food chain comprising birds, green plants, fish and man. The concentration of harmful chemical entering the food chain will be maximum in:
(a) plant
(b) man
(c) birds
(d) fish

2. Read the following and answer any four questions from 2(i) to 2(ii):
The amount of ozone in the atmosphere has begun to drop sharply from 1980s. This decrease has been linked to synthetic chemicals. In 1987, the United Nations Environment Programme (UNEP) succeeded in forging an agreement to freeze harmful chemicals production at 1986 levels. Based on the paragraph answer the following questions:

(i) At what level of atmosphere ozone layer is found?
(a) Troposphere
(b) Stratosphere
(c) Biosphere
(d) Ionosphere

(ii) At higher level of atmosphere radiations act upon oxygen molecule to form:
(a) Oxygen
(b) Ozone
(c) Carbon monoxide
(d) All of these

(iii) What is the major cause of ozone depletion?
(a) Chlorofluorocarbons
(b) Hydrochlorofluorocarbons
(c) Carbon tetrachloride and methyl chloroform
(d) All of these

(iv) Which of the following source is responsible for the depletion of ozone layer?

(v) In which of the following country Ozone hole has appeared?
(a) Africa
(b) North America
(c) Japan
(d) Antarctica