In the following food chain, vertical arrows indicate the energy lost to the environment and horizontal arrows indicate energy transferred to the next trophic level. Which one of the three vertical arrows (A, C and E) and which one of the two horizontal arrows (B and D) will represent more energy transfer? Give reason for your answer.
Answer
A will represent more energy transfer as compared to C and E.
B will represent more energy transfer as compared to D.
When green plants are eaten by primary consumers, a great deal of energy is lost as heat to the environment, some amount goes into digestion and in doing work and the rest goes towards growth and reproduction. An average of 10% of the food eaten is made available for the next level of consumers. This loss of energy takes place at every trophic level.
Alternatively accept - In accordance with 10% law of transfer of energy in a food chain only 10% of energy available at one trophic level is transferred to the next trophic level.
Explanation-
According to 10% Law
Only 10% energy available at particular trophic level is available for transfer to other trophic level
Remaining 90% energy is reflected back to the environment
Now in our question
There are 3 trophic level
Plants ------> Deer -------> Tiger
Suppose energy available with Plant is 100 joules
Out of this, only 10% of 100=10 joules will be transferred to Deer
Remaining 90 Joules will be reflected back to the environment
Hence
A=90
B=10
Now, energy available with Deer is 10 Joules
Out of this ,Only 1 Joule is transferred to Tiger
Remaining 9 joules is lost to the environment
hence
C=9
D= 1
Now, coming to tiger, he has 1 Joule energy
Out of this,90% will be lost to environment =90%*1=0.9
So E=0.9
Comparing Vertical arrows
A
C
E
Hence, A has highest energy lost to environment
Comparing Horizontal Rows
B
D
B has highest energy transfer'
