Tag: energy flow and loss

Questions Related to energy flow and loss

Two objects, A and B, have the same mass but the specific heat of A is larger than B. If both objects absorb equal amounts of energy,

  1. A will become warmer than B

  2. B will become warmer than A

  3. Both A and B will warm at the same rate

  4. A will get warmer, but B will get colder


Correct Option: B

Energy transformation through the food chain is

  1. Regular

  2. Comfortable

  3. Proposed

  4. Inefficient


Correct Option: D

What is an average incident energy?

  1. 3000kcal/m2/day

  2. 2000kcal/m2/day

  3. 5000kcal/m2/day

  4. 6000kcal/m2/day


Correct Option: A

The correct sequence of components through which energy may pass from initial source, through an ecosystem is

  1. Sun $\rightarrow$ Autotrophs $\rightarrow$ Heterotrophs $\rightarrow$ Environment $\rightarrow$ Space

  2. Space $\rightarrow$ Environment $\rightarrow$ Heterotrophs $\rightarrow$ Autotrophs $\rightarrow$ Sun

  3. Sun $\rightarrow$ Space $\rightarrow$ Environment $\rightarrow$ Heterotrophs $\rightarrow$ Autotrophs

  4. Sun $\rightarrow$ Space $\rightarrow$ Environment $\rightarrow$ Autotrophs $\rightarrow$ Heterotrophs


Correct Option: D
Explanation:

The energy flow starts from the sun. The light energy enters the space and then into the atmosphere. The energy in the atmosphere is captured by the plants which are autotrophs. Plants convert this light energy to chemical energy by photosynthesis. The food prepared by the plants is consumed by the heterotrophs. The heterotrophs are utilized by the decomposers.

So, the correct answer is option D. 

Energy transfer from one trophic level to another is

  1. 10%

  2. 5%

  3. 15%

  4. 20%


Correct Option: A
Explanation:

The amount of energy at each trophic level decreases as it moves through an ecosystem. As little as 10 percent of the energy at any trophic level is transferred to the next level; the rest is lost largely through metabolic processes as heat. The efficiency with which energy or biomass is transferred from one trophic level to the next is called as the ecological efficiency. Consumers at each level convert on average only about 10% of the chemical energy in their food to their own organic tissue (the ten-percent law). 

Therefore, the correct answer is option A.

Flow of energy declines as it passes from lower to higher trophic level. This is explained by

  1. First law of thermodynamics

  2. Second law of thermodynamics

  3. Newtons second law

  4. Newtons third law


Correct Option: B
Explanation:

Flow of energy declines as it passes from lower to higher trophic level. This is explained by second law of thermodynamics. According to this law, 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 'Second law of thermodynamics.'

Consider the components of a food chain producers $ \rightarrow\ $ herbivores $ \rightarrow\ $ carnivores $ \rightarrow\ $ top carnivores. Eventually what happens to all the energy passed from one element to the next?

  1. It recycles back to the producers

  2. It results in a much larger decomposer population

  3. It is dissipated into the environment.

  4. It is recaptured by another food chain


Correct Option: C
Explanation:

food chain can be described as a series of energy dilutors, the energy that fails to reach the next level being dissipated as heat or movement. Most of the energy contained in the food of animal consumers is used by them during the processes of food collection, digestion, and other essential metabolic activity.

So, the correct option is 'It is dissipated into the environment.'

The only requirement of an ecosystem is a constant input of energy that comes by the process of respiration

  1. True

  2. False


Correct Option: B
Explanation:

  • An ecosystem is a community of living organisms in conjunction with the nonliving components of their environment, interacting as a system. 
  • Energy flow is the amount of energy that moves through a food chain. 
  • Energy that is not used in an ecosystem is eventually lost as heat. 
  • Energy is passed on from one trophic level to the next trophic level and each time some energy is lost as heat into the environment. 
  • This is due to the fact that each organism must use some energy that they received from other organisms in order to survive. 
  • The top consumer of a food chain will be the organism that receives the least amount of energy.
So the given statement is false.

Read the following statements carefully:
(I) Energy transfer in the biotic world always proceeds from the autotrophs.
(II) Energy flow in undirectional
(III) Energy availability is maximum at the tertiary level.
(IV) There is loss of energy from one trophic level to that other.
Select the relevant statements for the forest ecosystem.

  1. I, II and IV

  2. I, II and III

  3. I, III and IV

  4. II, III and IV


Correct Option: A
Explanation:
A forest ecosystem is formed by the community of organisms which live in a forest. The relevant statement for the forest ecosystem are:
I→ Energy transfer in the biotic world always proceeds from the autotrophs as the plants and the trees are the major producers. 
II→ Energy flow is unidirectional.
IV→ There is a loss of energy from one trophic level to the other as the law of energy transfer is applicable to this ecosystem.