h******b
发帖数: 312 | 1 Not only 植物没有脑袋, but other orgnisms:
蚯蚓也没有，水螅也没有，四么虫和SARS病毒，E.coli都没有
so now we clearly know these creatures are different from plant, althought
they all don't have heads, what's that? It is just as imation and shakuras
said, plant don't need to react quickly to stimuli from outside, but others
do, so 蚯蚓也，水螅，四么虫，E.coli all have nervouse system, just no need to
be complicated and fancy as a head, its enough for them to react and manage
living.
Ah, SARS is left, virus just don't have nervouse syst | w********y
发帖数: 359 | 2 植物为啥没有脑袋？首先要搞明白植物和动物的区别。一切生物的基本命题不外乎生存和
繁殖。从这个意义上，可以说，“脑袋” 这个高级而脆弱，内涵90%以上为水分，通常生
长于顶部的圆形物体对植物生存太没有必要了。植物繁殖就更简单了，可以无性繁殖(如
扦插)也可以自交或异花授粉进行有性繁殖(种子) 。
任何一棵植物都是一部宏伟的生物化学巨作。植物为了生存必须适应环境，由复杂的生理
生化机理控制合成众多的化合物，从这点看，植物又比动物复杂许多。植物通过光合作用
，固定空气里面的炭素，吸收土壤里的水分和矿物质合成所有自身所需要的营养物质。不
仅如此，还提供地球上其它动物最根本的物质能量来源。
植物完全可以对外界刺激作出反射性的快速反应，比如含羞草，轻轻一碰，全身叶子都合
起来。还有一些捕食小昆虫的热带植物，在猎物进入囊内后会迅速合上囊盖。在诸如干旱
，寒冷等逆境条件下，植物可以在非常短的时间内关闭气孔停止光合作用，并迅速积累抗
性物质。。还有的植物在被虫子咬过后释放类似昆虫激素的物质，使咬它的虫子失去繁殖
能力。长期的进化如热带的仙人掌，为减少水分散失和动物侵扰，叶子异化成刺。
to
【在 h******b 的大作中提到】
: Not only 植物没有脑袋, but other orgnisms:
: 蚯蚓也没有，水螅也没有，四么虫和SARS病毒，E.coli都没有
: so now we clearly know these creatures are different from plant, althought
: they all don't have heads, what's that? It is just as imation and shakuras
: said, plant don't need to react quickly to stimuli from outside, but others
: do, so 蚯蚓也，水螅，四么虫，E.coli all have nervouse system, just no need to
: be complicated and fancy as a head, its enough for them to react and manage
: living.
: Ah, SARS is left, virus just don't have nervouse syst
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