How does the second law of thermodynamics relate to transformation of energy in a food chain?

The second law of thermodynamics says that as more chemical reactions occur,more heat energy is released in to the atmosphere. Apparently, heat energy is useless and more energy is transformed into heat energy, more entropy becomes prevalent. So as energy is being consumed and passed up the food chain, chemical reactions to digest the food occurs and , as a result, entropy increases. 
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Atissue is a group of connected cells that have a similar function within an organism.