Plants use photosynthesis to meet their survival needs by enabling them to

I believe plant use photosynthesis to meet their survival needs by enabling them to convert radiant energy into chemical energy. Photosynthesis is the process by which plants makes their own food using energy from sunlight. Green plants capture and store light energy from the sun through this process using chlorophyll. The process of photosynthesis produces the chemical energy that plant's cells need to carry out their activities.

That would be a working theory.