Answer:
plants are called photosynthetic autotrophs...
WHY ARE THEY CALLED PHOTOSYNTHETIC...?!? because they convert light energy (i.e. sunlight) to chemical energy (i.e. glucose) this process is called photosynthesis. The Photosynthetic formula is 6CO2 + 6H2O ---> GLUCOSE + 6O2......
WHY ARE THEY CALLED AUTOTROPHS....?!? because they make their own food by using inorganic sources that is Water and Carbon dioxide. they are fully independant from other organism. So they do not feed on any other organism for survival hence they are found on the bottom of the energy pyramid so if they wouldn't convert light energy into chemical energy all the animals would be dead because we are not autotrophs we can not make our own food by using inorganic sources we need already made organic food thats why those organisms which can not make their own food are called heterotrophs