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Plant Kingdom.
The plant kingdom comprises of about 260,000 known species of mosses, liverworts, ferns, herbaceous and woody plants, bushes, vines, trees, and various other forms that cover the Earth and are also found in waters. .
Plants range in a variety of sizes and shapes. Only a tiny percentage of plant species are directly used by humans for food, shelter, fiber, and drugs. Rice, wheat, corn, cotton, and tobacco, are some plants that economies and nations depend on. Humans benefits from the entire plant kingdom and its more than 1 billion years of photosynthesis. Plants have made the fossil fuels that provide power for our industries. Plants have supplied sufficient oxygen to the atmosphere to support the evolution of higher animals.
Plants are multicellular eukaryotes; their cells contain membrane-bound structures called organelles. The most important characteristic of plants is their ability to photosynthesize. During photosynthesis, plants make their own food by converting light energy into chemical energy, a process carried out in the green cellular organelles called chloroplasts.
Parts of the Plants.
Cells: The many varieties of plant species have distinct cell types that make up individual plants. Similarities do exist among all these cell types; however, these similarities indicate the common origin and the interrelationships of the different plant species. Each individual plant cell is at least partly self-sufficient, being isolated from its neighbors by a cell membrane, or plasma membrane, and a cell wall. The membrane and wall allow the individual cell to carry out its functions; at the same time, communication with surrounding cells is made possible through cytoplasmic connections called plasmodesmata.
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Tissue: vascular tissue, which guides water and nutrients to the cells of the plant; ground tissue, called pith at the center of the stem, which surrounds the vascular tissue.
