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Introduction to Organisms

Author(s): Deanne Erdmann, MS

The Kingdom Plantae

In the five-kingdom classification system, Plantae refers to green plants, excluding the green algae. The Kingdom Plantae includes the mosses, seed ferns, conifers, flowering plants and related groups. Plants are multicellular organisms that develop from embryos. Plants have cellulose in their cell walls that gives strength and structural support, and use chlorophyll a and b to transfer energy from the sun to chemical energy, a process called photosynthesis. 

In the life cycle of plants, the two multicellular body forms, the gametophyte (1n) and sporophyte (2n), alternate.The predominant form and pattern of this cycle is a key characteristic of differing plant groups.

Plants are adapted primarily for life on land and have had to overcome problems of water loss and transport. Various groups of plants approach the problem of reproduction, support and transport with ingenious adaptations of vascular tissue, roots, stems, leaves, pollen, seeds, fruits, and flowers.