Biology · Environmental Studies

Ecosystem Nutrition and Energy Flow

1,235 Questions

Ecosystem nutrition and energy flow questions cover trophic levels, food chains, and biodegradable materials. These concepts frequently appear in general science sections of major competitive exams. Review these questions to build a solid understanding of ecological interactions.

Trophic levels conceptFood chain orderAutotrophic nutritionEnergy assimilationScavengers and decomposers

Ecosystem Nutrition and Energy Flow Questions

Multiple choice zoology meaning of life energy flow and loss energy flow in a food chain energy flows

Which best describes the movement of energy and matter through living systems? 

  1. Energy flows while matter is cycled.

  2. Matter flows in two directions while energy flows in one direction.

  3. Energy is cycled while some matter is lost as heat.

  4. Energy forms chemical compounds while matter flows.

  5. Matter is always available while energy is cycled.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Energy is passed from one trophic level to the next trophic level. Hence energy flows through successive trophic levels in a food chain. 
Matter may be organic or inorganic. The organic and inorganic matter is produced, exchanged and moved within the ecosystem and this is called cycling. Hence matter is cycled.
So, the correct answer is 'Energy flows while matter is cycled'.
Multiple choice zoology meaning of life energy flow and loss energy flow in a food chain energy flows

Which one of the following is one way cycle?

  1. Carbon cycle
  2. H$ _{2}$O cycle

  3. Free energy cycle
  4. O$ _{2}$ cycle
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The transfer of energy in an ecosystem is always one way, from the sun to producers, from producers to herbivores, from herbivores to carnivores. The one way transfer of energy is in accordance with the laws of thermodynamics. 

Water, carbon and oxygen cycle in the ecosystem and are regularly exchanged between biotic and abiotic components.

Multiple choice zoology meaning of life energy flow and loss energy flow in a food chain energy flows

Flow of energy declines from low to higher trophic level in ecosystem, is mainly explained by

  1. First law of thermodynamics

  2. Second law of thermodynamics

  3. Both of the above

  4. None of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Ecosystem require a constant input of energy as every component of an ecosystem is regularly dissipating energy. Two laws of thermodynamics govern this flow of energy. 

According to first law of thermodynamics, energy can be transformed as well as transferred but is neither created nor destroyed. 
According to second law of thermodynamics, every activity and energy transformation is accompanied by dissipation of energy. 

The maximum energy in an ecosystem is available at lowest or producer level and as energy is transferred from producers to successively higher levels energy level gets diminished. Thus, the correct answer is option B.

Multiple choice zoology meaning of life energy flow and loss energy flow in a food chain energy flows

What percent of assimilated energy is used in respiration by the herbivores?

  1. 20%

  2. 30%

  3. 40%

  4. 60%
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Large amount of assimilated energy is used in respiration. In herbivores, 30% of assimilated energy is used in respiration. Herbivores are more efficient in using energy for their growth and development than animals. Hence, plants grow faster than animals. 

Thus, the correct answer is '30%.'

Multiple choice zoology meaning of life energy flow and loss energy flow in a food chain energy flows

Path of energy flow in an ecosystem is 

  1. Herbivores > Producers > Carnivores -> Decomposers

  2. Herbivores > Carnivores >Producers > Decomposers

  3. Producers > Carnivores > Herbivores > Decomposers

  4. Producers >Herbivores > Carnivores > Decomposers
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Ecosystem is made up of living and nonliving things. Living things or biotic things include plants and animals. Nonliving things or abiotic things include air, water, land.  It is composed of organisms interacting within communities. The driving force for an ecosystem is solar energy. Producers use solar energy to synthesize their food by the process of photosynthesis. From producers, the energy is transferred to herbivores. Herbivores eat producers. The energy is transferred from herbivores to carnivores. Carnivores eat herbivores. From carnivores, the energy is transferred to decomposers. They decompose organic matter of plants and animals.

Thus, the correct answer is 'Producers >Herbivores > Carnivores > Decomposers.'

Multiple choice zoology meaning of life energy flow and loss energy flow in a food chain energy flows

Which of the following receives the maximum energy?

  1. Producers

  2. Decomposers

  3. Primary consumers

  4. Secondary consumers
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Flow of energy declines as it passes from lower to higher trophic level. The energy decreases from one trophic level to the next trophic level because energy is lost as metabolic heat during transfer of energy. When food energy passes from producers to herbivores to carnivores, only 10% of energy is transferred from one trophic level to another trophic level. Hence, producers receives the maximum energy.
Thus, the correct answer is 'Producers.'
Multiple choice zoology meaning of life energy flow and loss energy flow in a food chain energy flows

Each successive trophic level has

  1. Less total energy

  2. More total energy

  3. Increased total energy

  4. Non estimated energy contents
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Pyramid of energy represents the amount of energy at each trophic level. In any ecosystem, flow of energy declines as it passes from lower to higher trophic level. Hence, the pyramid of energy is always upright. Each successive trophic level has less total energy. In this, the energy decreases from one trophic level to the next trophic level because energy is lost as metabolic heat during transfer of energy. When food energy passes from producers to herbivores to carnivores, only 10% of energy is transferred from one trophic level to another trophic level.

Thus, the correct answer is 'Less total energy.'

Multiple choice zoology meaning of life energy flow and loss energy flow in a food chain energy flows

Loss of energy from one trophic level to next higher trophic level is

  1. 30%

  2. 40%

  3. 60%

  4. 90%
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

According to the Lindeman's trophic efficiency rule, the 10% of energy is transferred from one trophic level to the next successive trophic level. The rest of the energy, that is 90% of energy is lost during transfer of energy from one trophic level to next higher trophic level. The first trophic level has the maximum energy. 

Thus, the correct answer is '90%.'

Multiple choice zoology meaning of life energy flow and loss energy flow in a food chain energy flows

In a food chain, energy flows

  1. From low to high level

  2. From high to low level

  3. From low to middle level

  4. From middle to low level
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

In a food chain, energy enters through producers. Producers such as plants synthesize their own food in presence of sunlight. They convert solar energy into chemical energy. From producers, the energy flows to the primary consumers to the secondary consumers to the tertiary consumer. Hence, the energy flow in a food chain is always from low to high level. During energy transfer, only 10% of energy is transferred from one trophic level to another trophic level.

Thus, the correct answer is 'From low to high level.'

Multiple choice zoology meaning of life energy flow and loss energy flow in a food chain energy flows

Lindemans energy transfer law states that only

  1. 20% energy is transferred to higher trophic level

  2. 10% energy is transferred to higher trophic level

  3. 30% energy is transferred to higher trophic level

  4. 50% energy is transferred to higher trophic level
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Ten percent law of energy transfer in food chains was given by Reymond LIndeman. It is also called as Lindeman's trophic efficiency rule. According to this rule, the 10% of transfer of energy is transferred from one trophic level to the next successive trophic level. The rest of the energy is lost during transfer of energy and during respiration. The first trophic level has the maximum energy. 

Thus, the correct answer is '10% energy is transferred to higher trophic level.'

Multiple choice zoology meaning of life energy flow and loss energy flow in a food chain energy flows

Which of the following statements regarding energy flow is/are false?
I. Detritus food chain begins with dead organic matter
II. In aquatic ecosystem, detritus food chain is the major conduit for energy flow
III. In terrestrial ecosystem a larger fraction of energy flows through grazing food chain
IV. Producers belong to the first trophic level of the food chain

  1. II and III only

  2. III and IV only

  3. I and IV only

  4. I and II only

  5. I, II and III only
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Statement II is false because the grazing food chain is often the major conduit in aquatic ecosystems, while the detritus food chain is more significant in terrestrial ecosystems. Statement III is false because the detritus food chain is the major conduit in terrestrial ecosystems.

Multiple choice zoology meaning of life energy flow and loss energy flow in a food chain energy flows

As biomass passes from one trophic level to another, the amount of total energy

  1. Declines

  2. Increases

  3. Remains unaffected

  4. None of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Energy flow is the amount of energy that flows from one trophic level to another trophic level in an ecosystem. It is unidirectional. In any given ecosystem, flow of energy occurs through different trophic levels. Producers or plants obtain their energy from the sun by photosynthesis. The primary consumers (herbivores) obtain their energy from the producers. The secondary consumers (carnivores) obtained their energy by using herbivores as a source of food and so on. The energy present at each successive trophic level is 10% of the previous trophic level. Hence, as biomass passes from one trophic level to another, the amount of total energy declines.

Thus, the correct answer is 'Declines.'

Multiple choice zoology meaning of life energy flow and loss energy flow in a food chain energy flows

In an ecosystem, the 10% of energy available for transfer from one trophic level to the next is in the form of

  1. Heat energy

  2. Light energy

  3. Chemical energy

  4. Mechanical energy
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

In an ecosystem, the ultimate source of energy is sun and solar energy is trapped by photoautotrophs or green plants which then convert it into chemical energy which is stored in carbohydrates. This chemical energy in the form of food is passed on from one organism to another in a food chain in the ecosystem. 

Therefore, the correct answer is option C.

Multiple choice zoology meaning of life energy flow and loss energy flow in a food chain energy flows

Bioenergetics can be defined as the process of energy transfer between trophic levels

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

  • Bioenergetics is a field in biochemistry and cell biology that concerns energy flow through living systems. 
  • This is an active area of biological research that includes the study of the transformation of energy in living organisms and the study of thousands of different cellular processes such as cellular respiration and the many other metabolic and enzymatic processes that lead to production and utilization of energy in forms such as adenosine triphosphate (ATP) molecules. 
  • That is, the goal of bioenergetics is to describe how living organisms acquire and transform energy in order to perform biological work. 
  • The study of metabolic pathways is thus essential to bioenergetics.
So the given statement is false.