Organisms in the kingdom Plantae, commonly referred to as plants, are multicellular, have specialized reproductive organs, unique cell structures and produce food using photosynthesis. This kingdom includes all land plants and some aquatic organisms as well. Plants are remarkably different from animals in appearance, but have important biological distinctions as well, especially at the cellular level.
One of the main characteristics of plants is that they are classified as multicellular eukaryotes. Plants have unique organelles called chloroplasts, along with cell walls created with cellulose. Plants also have special reproductive organs that produce reproductive cells. Male sex organs produce sperm, while the reproductive organs in females generate eggs. Plants have the unique ability to reproduce using asexual reproduction, which means that the entire fertilization process can take place in a single plant; no coupling or mating of male and female plants is necessary. Plants, depending on the species, may contain male and female reproductive organs. Plants are also distinguished by their use of photosynthesis to create food. For this process, they absorb large quantities of sunlight, which combines with water within their stems to create glucose, a type of sugar that plants use for energy. Some plants produce flowers and fruits while others do not, but all need the basic elements of sunlight, water and carbon dioxide to live and reproduce.