章节大纲

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  • 毫无种子的血管植物生命周期

    Close-up of a coiled fern leaf structure, known as a fiddlehead, displaying its green texture.

    What's a fiddlehead?
    ::小提琴头是什么?

    This leaf structure is known as a fiddlehead. Can you understand why? Does it look tasty? Nearly all ferns have fiddleheads, and many recipes exist on how to prepare fiddleheads. But this part of the plant, the leaf or the frond , also plays a very important role in the fern's .
    ::这种叶子结构被称为小提琴头,你知道为什么吗?它看起来很好吃吗?几乎所有小提琴头都有小提琴头,在如何培养小提琴头方面有许多食谱。但是,植物的这一部分,叶子或羽毛,在小提琴头中也扮演着非常重要的角色。

    Life Cycle of Seedless Vascular Plants
    ::毫无种子的血管植物生命周期

    Unlike , all vascular plants—including seedless vascular plants—have a dominant sporophyte generation. Seedless include clubmosses and ferns. Figure shows a typical fern life cycle.
    ::与众不同的是,所有血管植物——包括无种子血管植物——都拥有占支配地位的脊椎植物一代,无种子植物包括阴茎和发芽植物。

    Life cycle of a fern showing sporophyte and gametophyte stages with fertilization process.

    In the life cycle of a fern, the sporophyte generation is dominant.
    ::在胎儿的生命周期中,脊髓灰质素一代占主导地位。

    A mature sporophyte fern has the familiar leafy fronds . The undersides of the leaves are dotted with clusters of sporangia . Sporangia produce spores that develop into tiny, heart-shaped gametophytes . Gametophytes have antheridia and archegonia . Antheridia produce with many cilia ; archegonia produce eggs . occurs when sperm swim to an egg inside an archegonium . The resulting zygote develops into an embryo that becomes a new sporophyte plant. Then the cycle repeats.
    ::成熟的植物有熟悉的叶状花纹。 叶子的下侧有成堆的。 Sporangia 产生颗粒, 形成细小的、 心形的游戏植物。 植物植物有动脉炎和腹部炎。 生长多种硅的 Antheridia 生产; 考古产卵 。 当精子游到拱门内的卵中时, 就会发生卵子。 由此产生的形成胚胎, 形成一个新的植物。 然后循环重复 。

       

     

    Summary
    ::摘要

    • In vascular plants, the sporophyte generation is dominant.
      ::在血管植物中,脊髓灰质素一代占主导地位。
    • In seedless vascular plants such as ferns, the sporophyte releases spores from the undersides of leaves.
      ::在没有种子的血管植物中,如Ferns, 麻黄素释放出叶子下方的颗粒。
    • The spores develop into tiny, separate gametophytes, from which the next generation of sporophyte plants grows.
      ::螺旋会发展成细小的, 分开的游戏植物, 下一代的植物从中生长。

    Review
    ::回顾

    1. What role do leaves play in the reproduction of ferns?
      ::在后代的生殖中留下什么作用?
    2. Describe antheridia and archegonia and their functions.
      ::描述 anteridia 和 argegonia 及其功能。
    3. Create your own cycle diagram to represent the life cycle of a fern.
      ::创建您自己的循环图以代表胎儿的生命周期 。