Tag: energy flows

Questions Related to energy flows

Transfer of energy in different trophic levels of an ecosystem is

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

  1. Bioenergetics

  2. Biosystem

  3. Geobiocoenosis

  4. Holocoenosis

Show answer
Correct Option: A
Explanation:

Flow of energy in different trophic levels of an ecosystem is called as bioenergetics. It is also called as energy flow. In this, there is flow of energy through the food chain. Solar energy is converted to chemical energy by photosynthetic plants. From plants, the energy is transferred to primary consumers and secondary consumers in a food chain. Decomposers release energy back to the environment by decomposing organic waste matter.

Thus, the correct answer is 'Bioenergetics.'

Amount of energy transferred from one trophic level to next is

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

  1. 1.5%

  2. 10%

  3. 15%

  4. 20%

Show answer
Correct Option: B
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 '10%.'

Efficiency of energy transfer from one trophic level to the higher trophic level is called

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

  1. Assimilation efficiency

  2. Exploitation efficiency

  3. Lindeman's trophic efficiency rule

  4. Gross primary productivity

Show answer
Correct Option: C
Explanation:

Lindeman's trophic efficiency rule was introduced by Reymond Lindeman. 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 'Lindeman's trophic efficiency rule.'

The amount of usable energy remains constant as it is passed from one trophic level to another.

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

  1. True

  2. False

  3. Either

  4. Neither

Show answer
Correct Option: B
Explanation:
Organisms depend on the organisms of lower trophic levels for their energy requirements. There is a certain mass of living matter present in a trophic level at a particular time which is called standing crop and measured as mass of living organisms i.e. biomass. The biomass of species is measured in terms of dry weight. Transfer of energy from one trophic level to next trophic level follows 10 percent law known as Lindeman's law of trophic efficiency which states that the efficiency of energy transferred from one trophic level to the next higher trophic level is about 10%. So the energy decreases as it is transferred to subsequent trophic levels.
Hence, the statement given in the question is incorrect.
So, the correct answer is 'False'.

The maximum energy is stored at following trophical level in any ecosystem

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

  1. Producers

  2. Herbivores

  3. Carnivores

  4. Top carnivores

Show answer
Correct Option: A
Explanation:
A. Producers are the green plants which synthesise their own food using sunlight.
B. Herbivores are primary consumers which feed on producers.
C. Carnivores are secondary consumers who feed primary consumers.
D. Top carnivores are tertiary consumers who feed on other carnivores.
Maximum energy is stored in the trophic levels of producers as they synthesise their own food. They occupy the lowest trophic level and energy is transferred from them to higher subsequent trophic levels. As the energy decreases each time it is transferred to the next higher trophic level, the lowest trophic level i.e. producers, have maximum energy.
So, the correct answer is 'Producers'.  

The energy within an ecosystem is fixed and never changes.

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

  1. True

  2. False

  3. Either

  4. Neither

Show answer
Correct Option: B
Explanation:
In an ecosystem, sun is the ultimate source of energy. The solar energy is converted into chemical energy by plants and is stored in them. This energy is then passed to other organisms as they feed on producers. The transfer of energy from one trophic level to other follows 10 percent law according to which only 10% of the energy is passed from one trophic level to next and rest of the energy is lost in respiration and in the form of heat. Thus, energy within an ecosystem is not fixed.
Hence, the statement given in the question is not correct.
So, the correct answer is 'False'.

If $5$ joules of energy is available at producer level then find the energy transferred to the lion in the following food chain.
Plants $\rightarrow$ Deer $\rightarrow$ Lion

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

  1. $5$ joules

  2. $0.5$ joules

  3. $0.05$ joules

  4. $0.005$ joules

  5. None of these

Show answer
Correct Option: C
Explanation:
  • According to the 10% rule when energy is passed in an ecosystem from one tropic level to the next, only 10% of the energy is passed on and the rest is wasted.
  • 10% of (10% of 5 joules)=Energy transferred to the lion.
  • So, the correct choice is '0.05 joules'.

Grass $\rightarrow$ Deer $\rightarrow$ Tiger
In this food chain, the biomass of grass is $1$ tonne. The tiger biomass will be:

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

  1. $100 \,kg$

  2. $10 \,kg$

  3. $1 \,kg$

  4. $1000 \,kg$

Show answer
Correct Option: B
Explanation:

According to 10% law of Lindemann, if 1 tonne (1000 kg) biomass is present in grass, only 10% of it means 100 kg will go into deer and in tiger the biomass will be only 10 kg, i.e. 10% of deer's biomass.

So, the correct option is '10kg'.

An ecosystem is maintained by the flow of energy derived from the Sun. Energy trapped by plants varies from ecosystem to ecosystem. The table given shows energy absorption by different vegetations of different ecosystem.

Vegetation $\%$ of energy absorption
a) Aquatic ecosystem $15-16\%$
b) Grassland $14-15\%$
c) Mixed forest $13-14\%$
d) Modern $C _3$ crops $12-13\%$
e) Modern $C _4$ crops $10-12\%$

Find the correct match.

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

  1. C

  2. B

  3. A

  4. E

Show answer
Correct Option: C
Explanation:

An ecosystem is normally an open system because there are a continuous and variable entry and loss of energy and material. The ecosystem is the basic fundamental unit of ecology which includes both the organism and the non-living environment is influencing the property of each other and is necessary for the maintenance of life. The whole Earth can be known as biosphere or ecosphere.

Various plant and various vegetation have a different level of energy absorption. There is a grassland ecosystem and a forest ecosystem and many other.
So, the correct option is 'C' 

The pyramid of energy is the best representation of an ecosystem because it indicates

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

  1. Relation of all plants and animals

  2. Total energy present in an ecosystem

  3. The rate of flow of energy through the food chain

  4. None of the above

Show answer
Correct Option: C
Explanation:
  • The pyramid of energy shows the relationship between the flow of energy and different trophic level.
  • The pyramid of energy depicts the flow of energy in the ecosystem.
  • The source of energy in an ecosystem is the sun, the producers trap the solar energy and use it for photosynthesis which is in turn eaten by organisms of the higher trophic level such as primary consumers, secondary consumers.
  • So, the correct answer is 'The rate of flow of energy through the food chain'.