[Solved] The production of the shape and structure of each body region is A) organogenesis. B) differentiation. C) fertilization. D) morphogenesis. E) tissue specialization. Microscopic Algae: Tiny, often unicellular algae, not visible to the naked eye, that live in water and can perform photosynthesis. Phytoplankton: Microscopic floating algae and cyanobacteria that are the base of most aquatic food webs. Compare with zooplankton. See plankton and nanoplankton. Classification: The systematic organization of living things into categories based on shared attributes or evolutionary ancestry. Productive Region: An area or environment known for its high efficiency in generating goods, resources, or biological yield, often characterized by rich biodiversity or agricultural output.