Plant

Plant, living organism belonging to the plant kingdom (Planta). Green plants are unique in being able to synthesize their own organic molecules from carbon dioxide and water, using light-energy, by the process known as photosynthesis. Mineral nutrients are absorbed from the environment. Plants are the primary source of food for all other living organisms.

The possession of chlorophyll, the green photosynthetic pigment, is probably the most important distinction between plants and animals. Plants are generally stationary and have no nervous system, and the cell wall generally contains large amounts of cellulose. Some insectivorous plants obtain their food by trapping insects.

The higher plants (gymnosperms and angiosperms) are much the same in their basic anatomy and morphology. In a typical angiosperm, 4 main regions can be recognized: root, stem, leaf, and flower. Each region has one or more basic functions.

Plants cells are not all alike, and each one is adapted to do a certain job, but all are derived from a basic pattern. This basic plant cell tends to be rectangular and has a tough wall of cellulose, which gives it its shape. The cell membrane is inside the wall. Inside the membrane is the protoplasm, which contains the nucleus and chloroplasts and many other microscopic structures. In the center of the protoplasm there is a large sap-filled vacuole that maintains the cell's shape and plays an important part in the working of the whole plant.

Both sexual and asexual reproduction are widespread throughout the plant kingdom. Many plants are capable of both forms, and in some cases the life cycle of the plant may involve the two different forms.