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我國擁有高等植物居世界第幾位 我國擁有的高等植物居世界第幾位

  • 農業
  • 2023-04-19 18:39
我國擁有高等植物居世界第3位。高等植物包括苔蘚、蕨類、裸子植物和被子植物,常見的有葫蘆蘚、綠藻、鞭毛、銀耳、菌靈芝、蘑菇、松葉蕨、瘤足蕨、蘇鐵、銀杏、紅豆杉等。高等植物是由原始的低等植物經過長期演化而來的,是長期對陸生生活適應的結果。

  高等植物在發育周期中,有兩個不同的世代:一個是無性世代,它的植物體稱孢子體,孢子體能產生孢子進行無性繁殖。

  世代交替在高等植物中的表現各不相同。在苔蘚植物中配子體占絕對優勢,孢子體以寄生狀態存在,依靠著配子體供給它所需的養料二在蕨類植物中孢子體狀比較發達,配子體則退化為原葉體,但仍能獨立生活。

  裸子植物和被子植物的孢子體則更發達,而配子體則更加退化,寄附在孢子體上。越是高等的陸生植物,它的孢子體越發達,而配子體則越退化。

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