Like most "life processes", photosynthesis can be studied at various levels --- the global level (how it's important to ecosystems), the plant part level (how leaves are organized for the process), and/or the cellular level (the chemical reactions occuring in the chloroplasts of the plant cells in the leaves of the plant).
(leaves; are organized; T:for the process) (the chemical reactions; occuring; L:in the chloroplasts of the plant cells in the leaves of the plant)
leaves the chemical reactions
are organized occuring
T:for the process
L:in the chloroplasts of the plant cells in the leaves of the plant