Class 10 Science Chapter 15 Our Environment The answer to each chapter is provided in the list so that you can easily browse throughout different chapters NCERT Class 10 Science Chapter 15 Our Environment and select need one.
Class 10 Science Chapter 15 Our Environment
Also, you can read the SCERT book online in these sections Solutions by Expert Teachers as per SCERT (CBSE) Book guidelines. These solutions are part of SCERT All Subject Solutions. Here we have given Assam Board Class 10 Science Chapter 15 Our Environment Solutions for All Subjects, You can practice these here…
Multiple Choice Questions
Q.1. Which of the following constitutes a food chain?
( a ) Grass, wheat and mango.
( b ) Grass, goats and human.
( c ) Goat, cow and elephant.
( d ) Grass, fish and goat.
Ans :- ( b ) Grass, goats and human.
Q.2. In a food chain the initial organism is usually
( a ) Photosynthetic.
( b ) Herbivore.
( c ) Saprophytic.
( d ) Parasitic.
Ans :- ( a ) Photosynthetic.
Q.3. Which of the following represents a possible food chain found in a pond.
| Primary | Primary | Secondary |
| Producers | Consumers | Consumers |
| (a) Green algae | Fish | Mosquito Larvae |
| (b) Fish | Green algae | Mosquito Larvae |
| (c) Mosquito Larvae | Fish | Green algae |
| (d) Green algae | Mosquito Larvae | Fish |
Ans :- ( d ) Green algae Mosquito Larvae Fish
Q.4. Which of the following are decomposers of dead organisms?
Bacteria Fungi Viruses
( a ) No yes yes
( b ) Yes no yes
( c ) Yes yes no
( d ) Yes yes yes
Ans :- ( c ) Yes yes no
Q.5. Which of the following is an artificial ecosystem?
( a ) Pond.
( b ) Crop field.
( c ) Lake.
( d ) Forest.
Ans :- ( b ) Crop field.
Q.6. Disposable plastic plates should not be used because
( a ) They are made of light weight materials.
( b ) They are made of toxic materials.
( c ) They are made of biodegradable materials.
( d ) They are made of non-biodegradable materials.
Ans :- ( d ) They are made of non-biodegradable materials.
Q.7. In a food chain, the third trophic level is always occupied by :
( a ) Carnivores.
( b ) Herbivores.
( c ) Decomposers
( d ) Producers.
Ans :- ( a ) Carnivores.
Q.8. Accumulation of non-biodegradable pesticides in the food chain in increasing amount at each higher trophic level is known as :
( a ) Eutrophication.
( b ) Biomagnification.
( c ) Pollution.
( d ) Accumulation.
Ans :- ( c ) Pollution.
Q.9. 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 tarliery consumer.
Ans :- ( c ) Primary consumer to secondary consumer
Q.10. An ecosystem includes :
( a ) All living organisms.
( b ) Non-living objects.
( c ) Both living organisms and non-living objects.
( d ) All living organisms and input of sun’s energy.
Ans :- ( c ) Both living organisms and non-living objects.
Q.11. The decomposers in an ecosystem :
( a ) Convert inorganic material to simpler forms.
( b ) Convert organic material to inorganic forms.
( c ) Convert inorganic material into organic component.
( d ) Do not break down organic compound.
Ans :- ( b ) Convert organic material to inorganic forms.
Q.12. What will happen deer is missing in the food chain given below.
Grass → Deer → Tiger
( a ) The population of tigers increases.
( b ) The population of grass decreased.
( c ) Tigers will start eating grass.
( d ) The population of tigers decreases and the population of grass increases.
Ans :- ( d ) The population of tigers decreases and the population of grass increases.
Q.13. Organisms which synthesise carbohydrates from inorganic compounds by using radiant energy are called.
( a ) Decomposers.
( b ) Producers.
( c ) Herbivores.
( d ) Carnivores.
Ans :- ( b ) Producers.
Q.14. Organism of a higher trophic level which feed on several types of organisms belonging to a number of lower trophic levels constitute the :
( a ) Ecosystem.
( b ) Food web.
( c ) Ecological pyramid.
( d ) Food chain.
Ans :- ( b ) Food web.
Q.15. In the following groups of materials, which group/groups contain only non-biodegradable materials?
( i ) Wood, paper, leather.
( ii ) Polythene, detergent pvc.
( iii ) Plastic, detergent, grass.
( iv ) Plastic, bakelite, DDT.
( a ) ( iii )
( b ) ( iv )
( c ) ( i ) and ( iii )
( d ) ( ii ) and ( iv )
Ans :- ( d ) ( ii ) and ( iv )
Q.16. Which of the following statement is incorrect?
( a ) All green plants blue green algae are producers comperens.
( b ) Green Plants get their food from readymade organic comperens.
( c ) Producers prepare their own food from inorganic compounds.
( d ) Plants convert solar energy into chemical energy.
Ans :- ( b ) Green Plants get their food from readymade organic comperens.
Q.17. Which of the following group of organisms are not constituents of a food chain?
( i ) Grass, lion, rabbit, wolf.
( ii ) Plankton, man, fish, grasshopper.
( iii ) Wolf, grass, snake, tiger
( iv ) Frog, snake, eagle, grass, grasshopper.
( a ) ( i ) and ( iii )
( b ) ( iii ) and ( iv )
( c ) ( ii ) and ( iii )
( d ) ( i ) and ( iv )
Ans :- ( c ) ( ii ) and ( iii )
Q.18. In the figure given alongside, the various trophic levels are shown in the form of a pyramid. At which trophic level the maximum energy is available?
( a ) T₄
( b ) T₂
( c ) T₁
( d ) T₃
Ans :- ( c ) T₁
Q.19. One of the following is not a biodegradable material. This one is :
( a ) Cotton.
( b ) Animal bones.
( c ) Aluminium foil.
( d ) Wood.
Ans. ( c ) Aluminium foil.
Q.20. Which of the following is not a non-biodegradable maternal?
( a ) Nylon socks.
( b ) Plastic school bag.
( c ) Jute carry bag.
( d ) Polyester clothes.
Ans :- ( c ) Jute carry bag.
Q.21. The use of one of the following will pollute the environment. This one is :
( a ) Paper carry bags.
( b ) Cotton cloth carry bags.
( c ) Nylon cloth carry bags.
( d ) Jute carry bags.
Ans :- ( c ) Nylon cloth carry bags.
Q.22. One of the following is not a consumer. This one is :
( a ) Giraffe.
( b ) Antelope.
( c ) Algae.
( d ) Alligator.
Ans :- ( c ) Algae.
Q.23. Which of the following is not a producer?
( a ) Grass.
( b ) Zooplankton.
( c ) Phytoplankton.
( d ) Paddy.
Ans :- ( b ) Zooplankton.
Q.24. One of the following is a micro-consumer. This one is-
( a ) Ant.
( b ) Lice.
( c ) Fungi.
( d ) Mosquito.
Ans :- ( c ) Fungi.
Q.25. Which of the following act as decomposers in an ecosystem?
( a ) Lactobacillus bacteria.
( b ) Cyanobacteria.
( c ) Putrefying bacteria.
( d ) Rhizobium bacteria.
Ans :- ( c ) Putrefying bacteria.
Q.26. One of the following helps in the recycling of materials in an ecosystem. This one is :
( a ) Autotrophs.
( b ) Saprotrophs.
( c ) Omnivores.
( d ) Carnivores.
Ans :- ( b ) Saprotrophs.
Q.27. In the food chain comprising of a snake, grass, insect and frog, the secondary consumer is :
( a ) Insect.
( b ) Snake.
( c ) Frog.
( d ) Grass.
Ans :- ( c ) Frog.
Q.28. Sahara desert was formed over a period of time due to one of the following uncontrolled activities of man:
( a ) Excessive cutting down of forest plants and trees.
( b ) Excessive killing of large herbivores.
( c ) Excessive killing of large carnivores.
( d ) Excessive use of poisonous chemicals called herbicides.
Ans :- ( c ) Excessive killing of large carnivores.
Q.29. What provides the energy which then flows through a food chain?
( a ) Glucose.
( b ) Oxygen.
( c ) Respiration.
( d ) Sunlight.
Ans :- ( d ) Sunlight.
Q.30. Which pollutant released into the air during refrigeration and airconditioning is the greatest contributor to the depletion of ozone layer?
( a ) BHC.
( b ) DDT.
( c ) CFC.
( d ) UNEP.
Ans :- ( c ) CFC.
Q.31. In the food chain given below, if the amount of energy available at fourth trophic level is 5kj, what was the energy available at the producer level?
Grass → Grasshopper → Frog Snake →Hawk
( a ) 500 kj
( b ) 50 kj
( c ) 5000 kj
(d ) 5 kj
Ans :- ( c ) 5000 kj.
Q.32. Which of the following limits the number of trophic levels in a food chain?
( a ) Insufficient food supply from producer level.
( b ) Decrease in energy at higher trophic levels.
( c ) Increase in the number of organisms at higher trophic levels.
( d ) Accumulation of harmful chemicals at higher trophic levels.
Ans :- ( b ) Decrease in energy at higher trophic levels.
Q.33. What percentage of sun’s energy falling on the levels of green plants is utilised by the plants in the process of photosynthesis and stored as chemical energy of food?
( a ) 99 percent.
( b ) 10 percent.
( c ) 1 percent.
( d ) 20 percent.
Ans :- ( c ) 1 percent.
Q.34. The depletion of ozone layer in the upper atmosphere is mainly due to the emission of :
( a ) Unburnt hydrocarbons.
( b ) Chlorofluorocarbons.
( c ) Greenhouse gases.
( d ) Ultraviolet radiations.
Ans :- ( b ) Chlorofluorocarbons.
Q.35. In an ecosystem, the ten percent 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.
Ans :- ( c ) Chemical energy.
Q.36. The flow of energy in an ecosystem is always :
( a ) Unidirectional.
( b ) Bidirectional.
( c ) Cyclic.
( d ) Multidirectional.
Ans :- ( a ) Unidirectional.
Q.37. The excessive exposure of human to ultraviolet 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 )
Ans :- ( c ) ( i ) and ( iii )
Q.38. Which of the following gets the minimum energy through the food chain in an ecosystem?
( a ) Carnivore.
( b ) Large carnivore.
( c ) Producer.
( d ) Herbivore.
Ans :- ( b ) Large carnivore.
Q.39. A food chain comprises of cat, seed-eating bird, plants, and dog. The organism which will have the maximum concentration of harmful pesticides coming through the food chain is most-likely to be :
( a ) Cat.
( b ) Plants.
( c ) Dog.
( d ) Seed eating bird.
Ans :- ( c ) Dog.
Q.40. An aquatic food chain comprises of the organisms like tadpoles, weeds, fish and water beetles. The organism gets the minimum energy through this food chain is :
( a ) Water beetles.
( b ) Tadpoles.
( c ) Weeds
( d ) Fish.
Ans :- ( d ) Fish.
Q.41. Most of the water surface of a lake is covered with algae, This algae in a part of the food chain which also includes small fish, bird, larvae and big fish. Which of the following will obtain the maximum energy?
( a ) Big fish.
( b ) Bird.
( c ) Larvae.
( d ) Small fish.
Ans :- ( c ) Larvae.
Q.42. If the energy available at the producer level in a food chain is 150 J, how much energy will be transferred to tertiary consumer?
( a ) 15 J
( b ) 10 J
( c ) 1.50 J
( d ) 0.15 J
Ans :- ( d ) 0.15 J
Q.43. If the energy trans ferred to a tertiary consumer in a food chain is 10 J, how much energy was available to the primary consumer?
( a ) 100J
( b ) 500J
( c ) 1000 J
( d ) 5000 J
Ans :- ( c ) 1000 J
Q.44. In additions to wheat plants, a crop field ecosystem has organisms such as snake, peacock, eagle and mice. If the wheat plants are sprayed with pesticides periodically, which of the following will have the minimum concentration of pesticides in the body?
( a ) Snake.
( b ) Eagle.
( c ) Mice.
( d ) Peacock.
Ans :- ( c ) Mice.
Q.45. Which of the following in the best method to dispose of biological wastes from hospitals?
( a ) Landfill.
( b ) Recycling.
( c ) Incineration.
( d ) Composting.
Ans :- ( c ) Incineration.
Q.46. In an ecosystem :
( i ) The flow of energy is unidirectional
( ii ) The flow of materials is unidirectional.
( iii ) The flow of materials is cyclic.
( iv ) The flow of energy is cyclic.
( a ) ( i ) and ( ii )
( b ) ( ii ) and ( iii )
( c ) ( i ) and ( iv )
( d ) ( i ) and ( iii )
Ans :- ( d ) ( i ) and ( iii )
Q.47. The ten percent law is associated with
( a ) Transfer of energy from various trophic levels to decomposers ina food chain.
( b ) Transfer of ATP energy into muscular energy.
( c ) Transfer of chemicl energy from one organism to another.
( d ) Transfer of sun’s energy to the organisms called producers.
Ans :- ( c ) Transfer of chemical energy from one organism to another.
Q.48. The harmful chemical which is accumulating in human beings through food chain is :
( a ) Benzene hexachloride.
( b ) DDT.
( c ) Chlorofluorocarbon.
( d ) Abscisic acid.
Ans :- ( b ) DDT.
Q.49. O₂ is converted into O₃ by the action of :
( a ) Infrared radiations.
( b ) Ultraviolet radiations.
( c ) Gamma radiations.
( d ) Cosmic radiations.
Ans :- ( b ) Ultraviolet radiations.
Q.50. Which of the following can not be added in a composting pit to prepare compost?
( a ) Sunflower plants.
( b ) Fruit and vegetable peets.
( c ) Flowers of plastic.
( d ) Red worms.
Ans :- ( c ) Flowers of plastic.
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