CBSE Class 10 Answered

It is assummed that only 10% of the orginal energy will be completely transferred to the next trophic level and incorporated into tissue. Three things happen to energy in a trophic level transfer. Some energy is incorporated into tissue at the next level, most is lost in metabolism, and some remains for harvesting by decomposers in the form of organic waste.

So, if we begin with 1,000 KCal of energy incorporated into plant tissue via photosynthesis, only 100 KCal would be available to the primary consumer, 10 KCal to the secondary consumer, 1 KCal to the tertiary consumer, and only 0.1 KCal to the quaternary level. One can quickly see why it is impossible for many trophic level transfers to exist. There simply would not be enough energy available to support the next level.