All plants need water in order to live. They absorb water through their roots and the xylem brings it to all parts of the plant.
All plants need sunlight in order to perform photosynthesis. They absorb the light energy from the sun in the cholorplasts.
most of the photosynthesis occurs in the mesophyll cells inside a leaf which contain chlorophyll. The first step is plants capture the energy in light and water molecules split and release oxygen into the atmosphere.
sugars are made during the second step. CO2 from the air is converted into sugar by using energy stored & trapped by cholorphyll. CO2 combins with H atoms and form sugar molecules.
plants help maintain the atmosphere we breathe and photosynthesis produces most of the oxygen in the atmosphere