CBSE Class 10 Biology Case Study Questions Our Environment MCQs

Case/Passage – 1
Food chains are very important for the survival of most species. When only one element is removed from the food chain it can result in extinction of a species in some cases. The foundation of the food chain consists of primary producers. Primary producers, or autotrophs, can use either solar energy or chemical energy to create complex organic compounds, whereas species at higher trophic levels cannot and so must consume producers or other life that itself consumes producers.
Because the sun’s light is necessary for photosynthesis, most life could not exist if the sun disappeared. Even so, it has recently been discovered that there are some forms of life,
chemotrophs, that appear to gain all their metabolic energy from chemosythesis driven by hydrothermal vents, thus showing that some life may not require solar energy to thrive.

Question: If 10,000 J solar energy falls on green plants in a terrestrial ecosystem, what percentage of solar energy will be converted into food energy?
(a) 10,000 J
(b) 100 J
(c) 1000 J
(d) It will depend on the type of the terrestrial plant.   

Answer: B

Question: If Ravi is consuming curd/yogurt for lunch, which trophic level in a food chain he should be considered as occupying ?
(a) First trophic level
(b) Second trophic level
(c) Third trophic level
(d) Fourth trophic level 

Answer: C

Question: The decomposers are not included in the food chain.The correct reason for the same is because decomposers:
(a) Act at every trophic level of the food chain
(b) Do not breakdown organic compounds
(c) Convert organic material to inorganic forms
(d) Release enzymes outside their body to convert organic material to inorganic forms 

Answer: A

Question: Matter and energy are two fundament  al inputs of an ecosystem. Movement of
(a) Energy is bidirectional and matter is repeatedly circulating.
(b) Energy is repeatedly circulation and matter is unidirectional.
(c) Energy is unidirectional and matter is repeatedly circulating.
(d) Energy is multidirectional and matter is bidirectional. 

Answer: C

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

Answer: A

Case/Passage – 2
The diagram below shows a food web from the sea shore

Question: The mussel can be described as
(a) Producer
(b) Primary consumer
(c) Secondary consumer
(d) decomposer   

Answer: C

Question: Which trophic level is incorrectly defined?
(a) Carnivores – secondary or tertiary consumers
(b) Decomposers – microbial heterotrophs
(c) Herbivores – primary consumers
(d) Omnivores – molds, yeast and mushrooms   

Answer: D

Question:  The given figure best represents:  

(a) Grassland food chain
(b) Parasitic food chain
(c) Forest food chain
(d) Aquatic food chain   

Answer: A

Question: Why do all food chains start with plants?
(a) Because plants are easily grown
(b) Because plants are nutritious
(c) Because plants can produce its own energy
(d) Because plants do not require energy 

Answer: C

Question: In the food web, what two organisms are competing for food?

(a) A and B
(c) A and C  
(b) D and F
(d) B and D   

Answer: D

Question: Consider the following statements concerning food chains:
(i) Removal of 80% tigers from an area resulted in greatly increased growth of vegetation 
(ii) Removal of most of the carnivores resulted in an increased population of herbivores.
(iii) The length of the food chains is generally limited to 3 – 4 trophic levels due to energy loss
(iv) The length of the food chains may vary from 2 to 8 trophic levels
Which two of the above statements are correct?
(a) (i), (iv)
(b) (i), (ii)
(c) (ii), (iii)
(d) (iii), (iv)   

Answer: C

Question: Which of the following group of organisms are not included in ecological food chain?
(a) Carnivores
(b) Saprophytes
(c) Herbivores
(d) Predators     

Answer: B

Case/Passage – 3
Biosphere is a global ecosystem composed of living organisms and abiotic factors from which they derive energy and nutrients.
And ecosystem is defined as structural and functional unit of the biosphere comprising of living and non-living environment that interact by means of food chains and chemical cyclesresulting in energy flow, biotic diversity and material cycling to form a stable, self-supporting system 

Question: Which trophic level is incorrectly defined?
(a) Carnivores – secondary or tertiary consumers
(b) Decomposers – microbial heterotrophs
(c) Herbivores – primary consumers
(d) Omnivores – molds, yeast and mushrooms   

Answer: D

Question: The given figure best represents: 

(a) Grassland food chain
(b) Parasitic food chain
(c) Forest food chain
(d) Aquatic food chain   

Answer: A

Case/Passage – 4
Food chains are very important for the survival of most species.

Question. Matter and energy are two fundamental inputs of an ecosystem. Movement of
(a) Energy is bidirectional and matter is repeatedly circulating.
(b) Energy is repeatedly circulation and matter is unidirectional.
(c) Energy is unidirectional and matter is repeatedly circulating.
(d) Energy is multidirectional and matter is bidirectional.

Answer: C

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

Answer: A

Question. If 10,000 J solar energy falls on green plants in a terrestrial ecosystem, what percentage of solar energy will be converted into food energy?
(a) 10,000 J
(b) 100 J
(c) 1000 J
(d) It will depend on the type of the terrestrial plant.

Answer: B

Question. If Ravi is consuming curd/yogurt for lunch , which trophic level in a food chain he should be considered as occupying ?
(a) First trophic level
(b) Second trophic level
(c) Third trophic level
(d) Fourth trophic level

Answer: C

Question. The decomposers are not included in the food chain.The correct reason for the same is because decomposers:
(a) Act at every trophic level of the food chain
(b) Do not breakdown organic compounds
(c) Convert organic material to inorganic forms
(d) Release enzymes outside their body to convert organic material to inorganic forms

Answer: A

Case/Passage – 5
Observe the following diagram and answer the questions any four from (i) and (v)

Question. Effective segregation of wastes at the point of generation is very important. Select the appropriate statements giving the importance of waste segregation.
I. less waste goes to the landfills
II. better for public health and the environment
III. help in reducing the waste
IV. resulting in deterioration of a waste picker’s health
(a) both I and II
(b) both I and III
(c) both II and III
(d) both I and IV

Answer: A

Question. The given graph shows the amount of waste generated, dumped and treated in percentage. Identify the reason of low success rate of waste management process.

(a) only 15% of urban India’s waste is processed
(b) less than 60% of waste is collected from households
(c) more than 60% of waste is collected from households
(d) both (a) and (b)

Answer: A

Question. Choose the waste management strategy that is matched with correct example.
(a) Refuse Choose products that use less packaging
(b) Reduce Give unwanted toys and books to hospitals or schools
(c) Reuse Not using single use plastic
(d) Repurpose Making flower pot from used plastic bottle

Answer: D

Question. Recycling of paper is a good practice but recycled paper should not be used as food packaging because
(a) recycled papers may release color /dyes on food items
(b) recycled papers are not absorbent
(c) recycled papers can cause infection due to release of methane
(d) recycled papers are costly

Answer: C

Question. According to the ‘Solid Waste Management Rule 2016’, the waste should be segregated into three categories. Observe the table below and select the row that has correct information

Answer: B

Case/Passage – 6
Biosphere is a global ecosystem composed of living organisms and abiotic factors from which they derive energy and nutrients. And ecosystem is defined as structural and functional unit of the biosphere comprising of living and non-living environment that interact by means of food chains and chemical cycles resulting in energy flow, biotic diversity and material cycling to form a stable, self-supporting system

Question. The given figure best represents:

(a) Grassland food chain
(b) Parasitic food chain
(c) Forest food chain
(d) Aquatic food chain

Answer: A

Question. Consider the following statements concerning food chains:
(i) Removal of 80% tigers from an area resulted in greatly increased growth of vegetation
(ii) Removal of most of the carnivores resulted in an increased population of herbivores.
(iii) The length of the food chains is generally limited to 3 – 4 trophic levels due to energy loss
(iv) The length of the food chains may vary from 2 to 8 trophic levels Which two of the above statements are correct?
(a) (i), (iv)
(b) (i), (ii)
(c) (ii), (iii)
(d) (ii), (iv)

Answer: C

Question. Which trophic level is incorrectly defined?
(a) Carnivores – secondary or tertiary consumers
(b) Decomposers – microbial heterotrophs
(c) Herbivores – primary consumers
(d) Omnivores – molds, yeast and mushrooms

Answer: D

Question. The diagram below shows a food web from the sea shore

The mussel can be described as
(a) Producer
(b) Primary consumer
(c) Secondary consumer
(d) Decomposer

Answer: C

Question. Which of the following group of organisms are not included in ecological food chain?
(a) Carnivores
(b) Saprophytes
(c) Herbivores
(d) Predators

Answer: B