Tag: energy flow and loss

Questions Related to energy flow and loss

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.


Correct Option: B
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'

Maintenance of internal favourable conditions, despite changes in external environment is

  1. Entropy

  2. Steady state

  3. Enthalpy

  4. Homeostasis


Correct Option: D
Explanation:

Higher animals like mammals tend to maintain a constant internal environment despite changes in external environment. This is called as homeostasis, e.g., in humans a body temperature around 97 fahrenheit is considered normal. In summers when outside temperature is high or in winters when outside temperature is very low the body temperature remains constant. This is one example of homeostasis. The nervous and endocrine system closely interplay to maintain homeostasis. Therefore, the correct answer is option D.

The movement of energy and nutrients through living systems differs in what way? 

  1. Energy recycles while nutrients flow in two directions.

  2. Nutrients recycle while energy flows in one direction.

  3. Nutrients are lost as heat while energy forms chemical compounds.

  4. Nutrients are constantly available while energy is limited.

  5. Nutrients are lost as heat while energy is limited.


Correct Option: B
Explanation:
Energy is passed from one trophic level to the next trophic level. Hence energy flows in one direction through successive trophic levels in a food chain. Nutrients are produced from the matter. The 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 nutrients are recycled.
So, the correct answer is 'Nutrients recycle while energy flows in one direction'.

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.


Correct Option: A
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'.

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


Correct Option: C
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.

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


Correct Option: B
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.

The importance of ecosystem lies in

  1. Cycling of materials

  2. Flow of energy

  3. Both A and B

  4. None of the above


Correct Option: C
Explanation:

The ecosystem is an interaction between living beings (biotic component) and their physical environment (abiotic component).

The most important characteristics of any ecosystem are energy flow and cycling of materials. Green plants trap solar energy and convert it into a usable form, which is passed on to successive levels through food chains and food webs. The other important characteristic of the ecosystem is cycling of materials. This is called as the biogeochemical cycle, in which decomposers release nutrients back to the environment to maintain the ecosystem. Thus, the correct answer is option C.

Select correct answers :
(1) Flow of energy
(2) Flow of materials
(3) Flow information
(4) Flow of smoke

  1. 1, 2, 3 correct

  2. 1 and 2 correct

  3. 2 and 4 correct

  4. 1 and 3 correct


Correct Option: A

In terrestrial ecosystem, maximum energy is present in

  1. $T _3$

  2. $T _2$

  3. $T _1$

  4. $T _4$


Correct Option: C
Explanation:

The first trophic level is represented as T$ _1$. It includes producers. The second trophic level is represented as T$ _2$. It includes primary consumers. Similarly, third trophic level is represented as T$ _3$. It includes secondary consumers. In terrestrial ecosystem, maximum energy is present in T$ _1$, that is producers.

Thus, the correct answer is 'T$ _1$.' 

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

  1. 20%

  2. 30%

  3. 40%

  4. 60%


Correct Option: B
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%.'