Canadian Medical Guide > Biological Sciences > Biological Phenomena, Cell Phenomena, and Immunity > Plant Physiology Terms and Definitions

Plant Physiology

	Germination - The initial stages of the growth of SEEDS into a SEEDLING. The embryonic shoot (plumule) and embryonic PLANT ROOTS (radicle) emerge and grow upwards and downwards respectively. Food reserves for germination come from endosperm tissue within the seed and/or from the seed leaves (COTYLEDON). (Concise Dictionary of Biology, 1990)
	Photosynthesis - The formation of carbohydrates, with release of molecular oxygen, from carbon dioxide and water in the chlorophyll tissue of plants and blue-green algae under the influence of light. In bacteria, photosynthesis uses hydrogen sulfide, molecular hydrogen, and other reduced compounds in place of water, so that molecular oxygen is not released. (Dorland, 27th ed.)
	Plant Diseases - Diseases of plants.
	Plant Transpiration - The loss of water vapor by plants to the atmosphere. It occurs mainly from the leaves through pores (stomata) whose primary function is gas exchange. The water is replaced by a continuous column of water moving upwards from the roots within the xylem vessels. (Concise Dictionary of Biology, 1990)
	Tropism - The directional growth of an organism in response to an external stimulus such as light, touch, or gravity. Growth towards the stimulus is a positive tropism; growth away from the stimulus is a negative tropism. (From Concise Dictionary of Biology, 1990)

Plant Physiology Medical Definitions and Terms