The stroma is the region outside the

The stroma is the space outside the thylakoid membranes. Plant Photosystems, clusters of pigment and protein that absorb light energy, are found in saclike photosynthetic membranes called thylakoids.

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volcanoes (an event in the geosphere) release a large amount of particulate matter into the atmosphere. these particles serve as nuclei for the formation of water droplets (hydrosphere). rainfall (hydrosphere) often increases following an eruption, stimulating plant growth (biosphere).