Photosynthesis takes place inside plant cells in small things called chloroplasts. Chloroplasts contain a green substance called chlorophyll. This absorbs the light energy needed to make photosynthesis happen. Plants can only photosynthesise in the light.
Photosynthesis does the opposite of respiration. Carbon dioxide is absorbed and oxygen is produced. In order to study respiration in green plants we must block out the light, because although green plants respire all the time they only photosynthesize in the light.
All about Plants - Photosynthesis
Printout A plant is a member of the kingdom Plantae, a living organism that utilizes photosynthesis, a process in which energy from sunlight is converted to chemical energy (food).