geotropism 是什么意思

	n. 【生物学】向地性。 negative geotropism负向地性，背地性。 positive geotropism正向地性。

an orienting response to gravity

	1.	The main stems of a plant show negative geotropism as they grow upwards . 植物茎往上长时表现出负向地性。
	2.	An auxin increases the growth in length of a plant cell, thus causing the curving of a stem, or roof, in phototropism and geotropism . 植物生长素能加快植物细胞长势，因此使茎弯曲向着阳光，或使根深扎入土。

geotropism是什么意思