Question

what fulfills the carbon and energy requirements of the autotrophic organism

Answer 1

the atmospheres carbon dioxide

Answer 2

The energy and carbon requirement of a autotrophic organism like in plants, is fulfilled by the process known as photosynthesis. In this process water and carbon dioxide are taken from outside and in the presence of chlorophyll and sunlight, these raw materials are converted into carbohydrates, which provides energy.

Hope it helps u.