Tag: energy flow in an ecosystem

Questions Related to energy flow in an ecosystem

Pyramid of energy in a pond ecosystem is always

  1. Linear

  2. Inverted

  3. Upright

  4. Irregular


Correct Option: C
Explanation:
In pond ecosystem, the shape of pyramid of energy is always upright. It indicates the energy at each trophic level. In this, the energy at producer level is maximum, followed by primary consumers (herbivores), followed by secondary consumers (carnivores). The base of the pyramid of energy represents the producers in a pond ecosystem. 
Thus, the correct answer is 'Upright.'

Which of the following statements is incorrect?

  1. The species that invade a bare area are called pioneer species

  2. The entire sequence of communities that successively change in a given area called sere

  3. Pyramid of energy is always inverted

  4. Pyramid of numbers in a tree ecosystem can be inverted


Correct Option: C
Explanation:

The species that invade a bare area are called pioneer species. In primary succession on rocks, the pioneer species were lichens. The entire sequence of communities that successively change in a given area called sere. The individual transitional community is called seral stage. Pyramid of energy is always upright. Only 10% of energy is transferred from one trophic level to successive trophic level in a pyramid. Pyramid of numbers in a tree ecosystem can be inverted. In this, the first trophic level contains minimum number of individuals and top trophic level contains maximum number of individuals.

Thus, the correct answer is 'Pyramid of energy is always inverted.'

If the energy produced at the level of producers is 1000 J, the energy available for the secondary consumers is

  1. 1000 J

  2. 100 J

  3. 10 J

  4. 1 J


Correct Option: C
Explanation:

In a food chain, only 10% of energy is transferred from one trophic level to another trophic level. If the energy produced at the producer level is 1000 J, then the energy available at the primary consumer level will be 100 J and energy available at the secondary consumer level will be 10 J.

Thus, the correct answer is '10 J'.

Pyramid of energy is always upright. This is in accordance with the law of 

  1. Thermodynamics

  2. Tolerance

  3. Limiting factors

  4. Evolution


Correct Option: A
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. Hence, the pyramid of energy is always upright.

Thus, the correct answer is 'Thermodynamics.'

According to Charles Elton, which is not correct?

  1. Carnivores are at the top of the pyramid.

  2. Energy trapping is high at the top of the pyramid.

  3. Producers at the top of the pyramid.

  4. Both B and C.


Correct Option: D
Explanation:

Correct answer-(D)

Charles Elton, an English biologist, developed the idea of ecological pyramids. These pyramids are therefore also termed as Eltonian pyramids. An ecological pyramid may be defined as a graphic representation of the numbers or biomass or status of accumulated energy at different trophic levels in a food chain in an ecosystem. The Eltonian pyramid is a concept which relates to food consumption efficiency. According to Charles Elton, carnivores are at the top of the pyramid. Producers are at the bottom of the pyramid. They manufacture food and provide nutrition for the next level. Energy trapping is high at the base of the pyramid, i.e., producer level. The energy is highest at the producer level as it traps energy from the sun. It gradually decreases as one moves to subsequent levels, i.e. herbivores and different carnivores.

Choose the correct answers from the alternatives given :
One of the lessons from an energy pyramid is that

  1. only one-half of the energy in one trophic level is passed on to the next level

  2. the energy lost as heat or in cellular respiration is 10% of the available energy of each trophic level

  3. ecological efficiency is highest for primary consumers

  4. eating grain-fed beef is an inefficient means of obtaining the energy trapped by photosynthesis


Correct Option: D
Explanation:

An energy pyramid is the graphical representation of energy flow in a particular community. The different trophic levels represent a different group of animals. Here only ten percent of the energy is passed on to the next trophic level. As the organism of one trophic level is consumed by the organism of the next trophic level, energy decreases as it goes up the trophic level. So, the correct answer is "eating grain-fed beef is an inefficient means of obtaining the energy trapped by photosynthesis".

The pyramid of energy is always upright

  1. True

  2. False


Correct Option: A
Explanation:

An energy pyramid is a graphical representation designed to show the biomass or bio productivity at each trophic level in a given ecosystem. An energy pyramid is always upright because when energy flows from a particular trophic level, some energy is lost as heat at each step. Thus, the total amount of energy available for utilisation in the top levels is always less than the energy available in the lower levels. Therefore in the pyramid of energy in which each bar indicates the amount of energy present at each trophic level in a given time

So the given statement is true.

The graphic presentation of various aspects of ecosystems are in the form of pyramids. When such a presentation is made with reference to energy at different trophic levels, it will make

  1. An erect pyramid

  2. An inverted pyramid

  3. A cylinder

  4. A pyramid of variable shape


Correct Option: A
Explanation:
The pyramidal representation of trophic levels of different organisms based on their ecological position [producer to final consumer] is called as an ecological pyramid. The food producer forms the base of the pyramid and the top carnivore forms the tip. An energy pyramid represents the amount of energy at each trophic level and loss of energy at each transfer to another trophic level. Hence the pyramid is always upward, with a large energy base at the bottom.
So the correct option is 'an erect pyramid'.

Which of the following statement is incorrect regarding ecological pyramids

  1. The pyramid of energy is inverted in ocean ecosystem

  2. The pyramid of biomass is inverted in aquatic ecosystem

  3. The pyramid of numbers is upright in grass land ecosystem

  4. The pyramid of biomass is upright in grass land ecosystem


Correct Option: A

Which one of the following statements for pyramid of energy is incorrect, whereas the remaining three are correct?

  1. It is upright in shape.

  2. Its base is broad.

  3. It shows energy content of different trophic level organisms.

  4. It is inverted in shape.


Correct Option: D
Explanation:

Pyramid of energy is always upright and can never be inverted, because when energy flows from a trophic level to the next trophic level some energy is always lost as heat at each step.