Question

If 0.6 J of energy is NSP of a peacock, the energy found in a plant in the form of gross primary productivity is? (If the rate of respiration in plants is $25\% $of GPP)
Plant $ \to $Mouse $ \to $snake $ \to $Peacock
1. 600 J
2. 800 J
3. 200 J

Answer 1

Hint:-Gross primary production (GPP) is the quantity of chemical energy that primary producers generate over a given period, usually expressed as carbon biomass. Primary producers use a certain fraction of this fixed energy for cellular respiration and preservation of existing tissues. Net primary production (NPP) is called the residual fixed energy.

Complete Answer:-Raymond Lindeman established the $10\% $ rule. This law states that only $10\% $ of energy from organic matter is passed on as energy is moved from one trophic level to the other. In compliance with this rule, only about $10\% $ of the energy from organic matter is retained as flesh during the transition of energy from organic food from one trophic stage to the next. The remainder is lost during transition, broken down in respiration, or lost by higher trophic levels to incomplete digestion.
If we assume primary productivity is 600J in plants, and by theory, we know that at every trophic level only $10\% $energy will transfer.
The mouse will get $10\% $ of 600 that is 60 J
The snake will get $10\% $ of 60 that is 6 J
Peacock will get $10\% $ of 6 that is 0.6 J

So, the correct answer is option (1).

Note:- Net primary production is the rate at which net useful chemical energy is produced by all the autotrophs in an ecosystem. As noted, the difference between the rate at which useful chemical energy (GPP) is produced by plants in an ecosystem and the rate at which they use some of that energy during respiration is equal. To be oriented towards the growth and reproduction of primary producers, net primary production is available. As such, it is open to herbivores for consumption.