the process by which green plants and some others organisms use sunlight to synthetize food from carbon dioxide and water. photosynthesis in plants generally improves the green pigment chlorophyll and generates oxygen as a byproduct..
b) prop roots
mangrove trees grow near the water edges where the soil is wet and muddy. they are often subjected to waves and flooding. as a mean of extra support, they develop pitchfork like roots from the lower nodules in addition to the original root system. these are called prop roots which go down in the soil and anchor themselves. they branch further by trapping sediments in order to provide additional support.
their absorption of iron can decrease.