Biology · Environmental Studies

Ecosystem Nutrition and Energy Flow

1,093 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

If first trophic level represent 100,000 kcal of energy. According to Lindman's law, how much energy is available to the fourth trophic level?

  1. 10 kcal

  2. 100 kcal

  3. 1,000 kcal

  4. 10,000 kcal

  5. 100,000 kcal
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
If first trophic level represents 100,000 kcal of energy, in second level it will have 10% of 100000 = 10000 kcal.
In third level, 10 % of 10000 = 1000 kcal
In fourth level, 10% of 1000 = 100 kcal
The Ten percent law is the transfer of energy from one trophic level to the next was introduced by Raymond Lindeman (1942). According to this law, during the transfer of energy from organic food from one trophic level to the next, only about ten percent of the energy from organic matter is stored as flesh.
Multiple choice zoology meaning of life energy flow and loss energy flow in a food chain energy flows

Autotrophic species produce 400,000 kJ of energy in a tropical food web. The amount of energy at the level of secondary consumers is

  1. 40 KJ

  2. 400 KJ

  3. 4000 KJ

  4. 40, 000 KJ

  5. 4000, 000 KJ
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Energy transfer along each trophic level of a food chain exhibit loss of 90% energy as heat and transfer of only 10% energy to the next trophic level. The energy is lost in metabolic activities. According to this, out of 400,000kJ energy of primary producers, 40000kJ will be transferred to primary consumers and 4000kJ will be transferred to the secondary consumer. Tertiary consumers will obtain only 400kJ energy from secondary consumers while top consumers will obtain as little as 40kJ energy. Correct answer is option C.

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

According to Lindeman's 10% law, only 10% energy is transferred to the next trophic level. If the plants produce 100 units of energy, the amount of energy at the level of secondary consumers would be

  1. 1 unit

  2. 25 units

  3. 50 units

  4. 70 units

  5. 80 units
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

10 percent Law introduced by Lindeman states that only 10% of energy is transferred from one trophic level to another and 90% of the energy is lost during transfer, respiration and digestion processes. Therefore if plants (present at producers level) produces 100 units of energy, 10% of it will be transferred to primary consumers (10 units of energy) and 10% of the subsequent energy is transferred to secondary consumers (1 unit of energy). Hence, the correct answer is option A.

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

Only a small portion of chemical energy in an apple is transferred to an organism that eats it.
What happens to the majority of the chemical energy stored in the apple when another organism eats it?

  1. The majority of the energy is spontaneously lost to the surroundings.

  2. The majority of the energy is used to do some kind of cellular work in the apple.

  3. The majority of the energy is lost as heat energy to the surrounding environment.

  4. The majority of the energy is destroyed or recycled.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The transfer of energy from one trophic level to another follows the 10% law of energy transfer. So, of the total energy created only 10% is passed on from the producers to the consumers while rest is used by the producer to carry out its activities

So, the correct answer is 'The majority of the energy is used to do some kind of cellular work in the apple'

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.