Tag: meaning of life

Questions Related to meaning of life

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'.

The cost of other ecosystem services like recreation and nutrient cycling are?

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

  1. $> 10\%$ each

  2. $< 6\%$ each

  3. $< 10\%$ each

  4. $6\%$ each

Show answer
Correct Option: A
Explanation:

The cost of ether ecosystem services like recreation and nutrient cycling are > 10% each.

The importance of ecosystem maintenance lies in

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

  1. Cycling of materials

  2. Flow of energy

  3. Both of the above

  4. None of the above

Show answer
Correct Option: C
Explanation:

An ecosystem comprises of biotic and abiotic components which interact with each other to maintain an equilibrium. A major focus of ecosystem ecology is on functional processes, ecological mechanisms, that maintain the structure and services produced by ecosystems. These include primary productivity (production of biomass), decomposition, and trophic interactions. The various trophic levels of an ecosystem interact with each other by  a flow of energy and cycling of materials from one trophic level to the other.

Which of the cycle is concerned with energy flow in the ecosystem?

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

  1. Food cycle

  2. O$ _2$ cycle

  3. Cl$ _2$ cycle

  4. All of the above

Show answer
Correct Option: A
Explanation:

A food cycle is associated with energy flow in the ecosystem. It contains several trophic levels which are interdependent to each other for energy. Only 10% of energy can be transferred to the successive trophic level and rest 90% get utilise in their life processes.

Thus, the correct answer is option A.

One way cycle is

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

  1. CO$ _2$ cycle

  2. H$ _2$O cycle

  3. Free energy cycle

  4. O$ _2$ cycle

Show answer
Correct Option: C
Explanation:

Free energy cycle is the unidirectional cycle in our ecosystem. In other cycles like oxygen cycle, carbon dioxide cycle and water cycle, the basic elements are circulated and cycled whereas, in free energy cycle, energy flows from solar energy to producers and then consumers to decomposers. 


The transfer of energy from a level to another is governed by Law of thermodynamics. The average efficiency of energy transfer from herbivores to carnivores level is

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

  1. 10%

  2. 25%

  3. 5%

  4. 50%

Show answer
Correct Option: A
Explanation:

The number of trophic levels in the grazing food chain is restricted as the transfer of energy follows 10 per cent law only 10 per cent of the energy is transferred to each trophic level from the lower trophic level.