| 释义 |
Gravitropisms | 《英文msh词典》Gravitropisms | | [入口词] Gravitropisms | | [主题词] Gravitropism | | [英文释义] The directional growth of organisms in response to gravity. In plants,the main root is positively gravitropic (growing downwards) and a main stem is negatively gravitropic (growing upwards),irrespective of the positions in which they are placed. Plant gravitropism is thought to be controlled by auxin (AUXINS),a plant growth substance. (From Concise Dictionary of Biology,1990) |
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