Energy Flow MCQs and Answers

Are you looking for Energy Flow MCQs and Answers for medical entrance examinations? If yes, these are some most important multiple choice questions and answers on NCERT Class-12 Biology, Chapter-14 (Ecosystem).

Here we composed these Energy Flow MCQs and Answers after reading the chapter on Ecosystem from the NCERT book on Class 12 Biology. The questions are topics-wise and the students can relate the questions easily to the most important topics of this chapter.

Energy Flow MCQs and Answers

1. What is the only source of energy for all ecosystems on Earth?

a) Water

b) Sun

c) Plants

d) Animals

Answer: b


2. Which is an exception in an ecosystem where the sun is not the source of energy?

a) Deep-sea hydro-thermal ecosystem

b) Terrestrial ecosystem

c) Lake ecosystem

d) Desert ecosystem

Answer: a


3. What is the spectral range of solar radiation in that photosynthetic organisms are able to use in the process of photosynthesis called?

a) Photosynthetically Reactive Radiation

b) Photosynthetically Active Radiation

c) Photosynthetically Deactive Radiation

d) Photosynthetically Trapped Radiation

Answer: b


4. What percent of the incident solar radiation is photosynthetically active radiation (PAR)?

a) 100%

b) 85%

c) 20%

d) 50%

Answer: d


5. What percent of PAR is captured by plants?

a) 1%

b) 20-30%

c) 2-10%

d) 50%

Answer: c


6. On what are the organisms are dependent on their food?

a) Consumers

b) Producers

c) Decomposers

d) Scavengers

Answer: b


7. How is the flow of energy from the sun to producers and then to consumers?

a) Multidirectional

b) Bidirectional

c) No direction

d) Unidirectional

Answer: d


8. From which law of energy the ecosystem are not exempted?

a) Zeroth law

b) First law of thermodynamics

c) Second law of thermodynamics

d) Fifth law of thermodynamics

Answer: c


9. What are the green plants in the ecosystem termed as?

a) Scavengers

b) Consumers

c) Decomposers

d) Producers

Answer: d


10. Who are the major producers in a terrestrial ecosystem?

a) Phytoplankton

b) Zooplankton

c) Green plants

d) Birds

Answer: c


11. Who are the major producers in an aquatic ecosystem?

a) Zooplankton

b) Phytoplankton

c) Fungi

d) Bacteria

Answer: b


12. How sunlight is much is reflected back out of the total sunlight reaching Earth?

a) 100%

b) 50%

c) 34%

d) 10%

Answer: c


13. How much percent of light reaches the Earth’s surface out of the total sunlight?

a) 20%

b) 56%

c) 0.1%

d) 30%

Answer: b


14. What amount of sunlight is held the ozone layer, water vapor, and atmospheric gases out of total sunlight reaching Earth?

a) 50%

b) 8%

c) 20%

d) 10%

Answer: d


15. What does this statement “The energy passed from producers to consumers (herbivores) does not go back to producers (autotrophs)” states about the flow of energy?

a) Flow is unidirectional

b) Flow has no specific direction

c) Flow is bidirectional

d) Flow is multidirectional

Answer: a


16. What is a group of organisms that transfer food energy through a linear series of processes such as eating and being eaten called?

a) Detritus

b) Food chain

c) Decomposers

d) Producers

Answer: b


17. What is a network of food chains interconnecting at various trophic levels and representing feeding relationships within a community called?

a) Food web

b) Decomposers

c) Herbivores

d) Food industry

Answer: a


18. What is the food chain beginning with host and ending with a parasite (ecto as well as endoparasite) called?

a) Detritus food chain

b) Parasitic food chain

c) Grazing food chain

d) Terrestrial food chain

Answer: b


19. What are the organisms that cannot manufacture their own food and obtain ready-made organic food from producers called?

a) Decomposers

b) Autotrophs

c) Scavengers

d) Consumers

Answer: d


20. To which trophic level do producers (photosynthesizers or autotrophs) belong?

a) Second

b) Third

c) First

d) Fifth

Answer: c


21. Which are the three types of consumers?

a) Autotrophs, heterotrophs, and decomposers

b) Herbivores, carnivores, and decomposers

c) Producers, heterotrophs, and decomposers

d) Herbivores, heterotrophs, and carnivores

Answer: b


22. How many levels do carnivores occupy?

a) 8

b) 1

c) 5

d) 3

Answer: d


23. To which trophic level do top or ultimate carnivores belong?

a) T1

b) T3

c) T4

d) T10

Answer: c


24. What is the step or division that organisms occupy in a food chain that is characterized by the method of obtaining its nutrition to fulfill its energy requirements called?

a) Trophic level

b) Food chain

c) Food web

d) Food pyramid

Answer: a


25. What is the number of trophic levels equal to?

a) Number of producers

b) Number of consumers

c) Number of divisions in a food chain

d) Number of carnivores

Answer: c


26. Which organisms are included in the last trophic level?

a) Autotrophs

b) Decomposers

c) Carnivores

d) Producers

Answer: b


27. Which organisms do not have any fixed trophic levels?

a) Decomposers

b) Autotrophs

c) Parasites

d) Carnivores

Answer: c


28. What is a parasitic food chain alternatively called?

a) Detritus food chain

b) Auxilliary food chain

c) Grazing food chain

d) Trophic level

Answer: b


29. What is a food chain beginning with detritus on which decomposers feed called?

a) Grazing food chain

b) Parasitic food chain

c) Primary food chain

d) Detritus food chain

Answer: d


30. What is a food chain consisting of autotrophs, heterotrophs, and carnivores called?

a) Grazing food chain

b) Quaternary food chain

c) Parasitic food chain

d) Detritus food chain

Answer: a


31. What is the missing level?

? → Heterotrophs → Decomposer?

a) Carnivore

b) Autotrophs

c) Scavengers

d) Humans

Answer: b


32. What is the missing level?

Autotrophs → ? → Decomposer

a) Heterotrophs

b) Carnivore

c) Producer

d) Scavengers

Answer: a


33. What is the missing level?

Autotrophs → Heterotrophs → ?

a) Producer

b) Decomposers

c) Scavengers

d) Plants

Answer: b


34. Which is the missing level of the organization?

Autotrophs → Herbivores → Carnivores → ? → Decomposers

a) Producers

b) Detritivores

c) Scavengers

d) Top carnivores

Answer: d


35. Which organisms form trophic levels in an ecosystem?

a) Only bacteria

b) Only plants

c) Organisms linked in the food chain

d) Only consumers

Answer: c


36. What amount of sunlight is used for photosynthesis?

a) 10%

b) 0.02%

c) 2%

d) 80%

Answer: b


37. During the flow of energy in an ecosystem, in which form is the energy dissipated during various metabolic activities?

a) Ammonia

b) Vapours

c) Photons

d) Heat

Answer: d


38. Which is the missing organism?

Detritus → ? → Frog → Snake → Peacock

a) Elephant

b) Tiger

c) Earthworm

d) Ostrich

Answer: c


39. What is a grazing food chain alternatively called?

a) Parasitic food chain

b) Detritus food chain

c) Auxiliary food chain

d) Predator food chain

Answer: d


40. What percent of energy is transferred in a food chain from one trophic level to another?

a) 35%

b) 20%

c) 10%

d) 54%

Answer: c


41. Which law states that there is a transfer of 10 percent energy in a food chain from one trophic level to another?

a) Blackman Law

b) 10 percent law

c) Hardy Weinberg principle

d) Mendel’s law

Answer: b


42. Which of the following consumers belong to the third level of energy flow?

a) Herbivores

b) Top carnivores

c) Carnivores

d) Decomposers

Answer: c


43. What do we study in ecological energetics?

a) Amount of air reaching Earth

b) Quantity and path of energy flow from producers to consumers

c) Amount of vacuum in the universe

d) Quality of energy used by green plants for photosynthesis

Answer: b


44. Who formulated the 10% law of a food chain?

a) Blackman

b) Ernst Rutherford

c) Gregor Mendel

d) Raymond Lindemann

Answer: d


45. How should be the food chain so that a greater amount of energy is available for top consumers?

a) Shorter

b) Longer

c) Moderate

d) Neutral

Answer: a


46. Which of the following phenomenon is responsible for the initiation of a food chain?

a) Decomposition

b) Respiration

c) Fixation

d) Photosynthesis

Answer: d


47. Which of the following organisms contain the greatest amount of energy?

a) Heterotrophs

b) Decomposers

c) Autotrophs

d) Scavengers

Answer: c


48. What is the trophic level of a lion in a forest ecosystem?

a) T1

b) T3

c) T0

d) T4

Answer: d


49. On what does the number of individuals in each trophic level depend on?

a) Number of individuals at upper trophic level

b) Number of individuals at top-most trophic level

c) Number of individuals at lower trophic level

d) Amount of sunlight reaching the Earth’s surface

Answer: c


50. What happens when the food energy passes from herbivores to carnivores and to the next organism?

a) Amount of energy increases

b) Amount of energy decreases

c) Energy becomes zero

d) Energy remains unchanged

Answer: b


51. What is the energy stored at the consumer level called?

a) Primary energy

b) Tertiary energy

c) Secondary productivity

d) Net productivity

Answer: c


52. Who forms the new organic matter giving rise to secondary productivity?

a) Producer

b) Consumer

c) Scavenger

d) Decomposer

Answer: b


53. Which of the following is the driving force of an ecosystem?

a) Biomass

b) Consumer

c) Producer

d) Solar energy

Answer: d


54. Which of the following event occurs in an ecosystem?

a) Unidirectional movement of energy

b) Coupled process of cycling of energy and nutrients

c) Independent cycling of energy

d) Recycling of micro and micronutrients at the same speed

Answer: a


55. What are the food levels in an ecosystem called?

a) Decomposer level

b) Trophic levels

c) Producer levels

d) Consumer levels

Answer: b


56. In general, a food chain consists of how many trophic levels?

a) Four

b) Zero

c) Two

d) One

Answer: a


57. How many trophic levels do green plants constitute?

a) Third trophic level

b) First trophic level

c) Last trophic level

d) Zero level

Answer: b


58. Who are the primary consumers of a biotic community?

a) Omnivores

b) Scavengers

c) Detritivores

d) Herbivores

Answer: d


59. Which of the following organisms belong to the category of primary consumers?

a) Plants and phytoplankton

b) Eagle and snakes

c) Cattle and zooplankton

d) Fungi and beetles

Answer: c


60. What are decomposers?

a) Autotrophs

b) Heterotrophs

c) Parasites

d) Organotrophs

Answer: b


61. A chicken has just eaten a worm. When a man sees this, he eats that chicken. To which trophic level does the man belong?

a) Secondary consumer

b) Primary consumer

c) Producer

d) Tertiary consumer

Answer: d


62. What will happen if we remove the decomposers from an ecosystem?

a) Energy flow stops

b) Consumers die

c) Mineralization will not occur

d) Plants won’t receive solar energy

Answer: c


63. Whose population is highest in an ecosystem?

a) Primary producers

b) Secondary consumers

c) Primary consumers

d) Decomposers

Answer: d


64. Which one of the following is the correct sequence of a grassland food chain?

a) Grass → Wolf → Bacteria → Deer

b) Grass → Deer → Fungi → Wolf

c) Grass → Deer → Wolf → Fungi

d) Grass → Fungi → Wolf → Deer

Answer: c


65. Which one of the following is the correct sequence of an aquatic food chain?

a) Phytoplankton → Fishes → Fungi → Zooplankton

b) Phytoplankton → Zooplankton → Fishes → Fungi

c) Phytoplankton → Fungi → Zooplankton → Fishes

d) Zooplankton → Phytoplankton → Fishes → Fungi

Answer: b


Are you curious about how energy flows? Here are some frequently asked questions about energy flow to help you better understand this important concept.

FAQs on Energy Flow

Q1. What is energy flow?

Answer: Energy flow is the process by which energy is transferred from one place to another. This can happen in a variety of ways, such as through the transfer of heat or the movement of electrons.

Q2. What are some examples of energy flow?

Answer: One example of energy flow is the transfer of heat from the Sun to the Earth. This happens because the Sun is much hotter than the Earth, so energy flows from the Sun to the Earth in the form of heat.

Another example of energy flow is the flow of electricity. This happens because electrons are constantly moving around, and when they flow through a conductor, such as a wire, they create an electric current.

Q3. What are the benefits of energy flow?

Answer: Energy flow is essential for life on Earth. Without the transfer of heat from the Sun, the Earth would be a cold, lifeless place. And without the flow of electricity, we would not be able to power our homes or devices.

Energy flow is also important for many industries. For example, the production of electricity relies on the flow of electrons through power plants. And the process of photosynthesis, which is used to produce food for plants, relies on the flow of energy from the Sun.

Q4. What are some challenges with energy flow?

Answer: One challenge with energy flow is that it is not always efficient. For example, when heat flows from a hot object to a cold object, some of the heat is lost in the process. This is why it is important to find ways to improve the efficiency of energy.

Have any other questions about Energy Flow? Leave a comment below and we’ll do our best to answer them!

Comments