Ferns produce spore capsules contained in the sporangium (plural: sporangia), a structure localized on the undersides of the leaves. Moreover, the sporangia are borne in clusters known as sori (singular sorus). The spores are single reproductive cells that, when mature, are released from the sporangium to germinate on soil and produce new ferns. In a fern sporangium, the maximum number of spores is 64, although this number depends on the species.
Light energy is absorbed by a chlorophyll molecule and the photon is passed along a pathway to other chlorophyll molecules. The energy culminates in a molecule of chlorophyll found in the reaction center.