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External Stimuli
7.13A External Stimuli
Term | Definition |
---|---|
EXTERNAL STIMULUS | A change in the environment outside of the organs. |
FEEDBACK MECHANISM | A response within a system that influences the activity of that system. |
FORCE | A push or pull that can change the position or most of an object. |
GEOTROPISM | Growth that happens in organisms in response to gravity, such as the downward growth of plant roots. |
HOMEOSTASIS | The body ability to keep the internal balance. |
MOTION | A change in position over time. |
PHLOEM | The vascular tissue in plants that conducts sugars and other metabolic products downward from the leaves. |
PHOTOTROPISM | Growth of a plant shoot toward or away from light. |
ROOT SYSTEM | All of a plant's roots, which anchor it in the soil, absorb and transport minerals and water, and store food. |
SHOOT SYSTEM | The aerial portion of a plant body, consisting of stems, leaves, and (in angiosperms) flowers. |
STABLE | Balanced; unchanging. |
STIMULUS | A thing or event that evokes a specific functional reaction in an organ or tissue. |
TRANSPIRATION | The process by which water is lost through a plant's leaves. |
TROPISM | The turning of all or part of an organism in a particular direction in response to an external stimulus. |
TURGOR PRESSURE | The pressure that is exerted on the inside of cell walls and that is caused by the movement of water into the cell. |
XYLEM | Vascular tissue that carries water upward from the roots to every part of a plant. |