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胚珠的结构特点一句话行了

更新时间: 2020-09-12 00:00:00     

白色小球状,有胚珠多数生于侧膜胎座上果肉质,长椭圆形。

胚珠为子房内着生的卵形小体,是种子的前体,为受精后发育成种子的结构。被子植物的胚珠包被在子房内,以珠柄着生于子房内壁的胎座上,由珠柄、珠被、珠孔和珠心所组成。裸子植物的胚珠裸露地着生在大孢子叶上。一般呈卵形。其数目因植物种类而异。

关键词: 结构 特点 一句话

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