| 释义 |
〔reagin〕A substance present in the blood of individuals having a positive serological test for syphilis.梅毒反应毒：个体血液中的一种物质，可对梅毒产生向性血清反应〔geotropism〕The growth of a living organism in response to gravity, as the downward growth of plant roots.对于地心引力的向性：有机体的生长对地心引力的向性，如植物根部向下长〔geotaxis〕Movement of a motile organism using the earth's gravity for orientation.趋地性：生物以地球重力为定向因素的向性〔tropism〕The turning or bending movement of an organism or a part toward or away from an external stimulus, such as light, heat, or gravity.向性，向性运动：生物体或其一部分做的趋向或远离外部刺激（如光、热、重力）的运动 |