Answer:
Plants and animals took up different evolutionary pathway millions of years ago.
In the prebiotic earth, the CO2 levels were insanely high, and the solar input was quite high due to which the initially evolved cells were photosynthetic , so that they can harness the solar energy, and because they need a carbon source, they relied on the Carbon from CO2.
In this process, the atmospheric gaseous content changed, as predecessors of plants gave out Oxygen over millions of years.
Gradually , the atmosphere was now oxygen rich and hence predecessors of animals evolved a mechanism to utilise this oxygen , and as a byproduct started releasing CO2.
Over the next years , these two diverse groups specialised and hence , became increasingly different.
Explanation:
