章节大纲

  • Close-up of moss with small capsules producing spores, illustrating reproduction in nonvascular plants.

    Have you ever noticed these little capsules on moss ?
    ::你有没有注意到这些小胶囊 在苔上?

    These tiny capsules produce spores . This is one stage in the process of in the mosses. Remember mosses and other seedless plants do not have flowers , so their life cycle is quite different from other plants.
    ::这些微小的胶囊会产生螺旋。这是苔胱过程中的一个阶段。记住苔胱和其他没有种子的植物没有鲜花,因此它们的生命周期与其他植物有很大不同。

    Reproduction in Seedless Plants
    ::无种子植物的生殖

    Seedless plants can reproduce asexually or sexually. Some seedless plants, like hornworts and liverworts , can reproduce asexually through fragmentation . When a small fragment of the plant is broken off, it can form a new plant.
    ::没有种子的植物可以性繁殖或性繁殖。 一些没有种子的植物,如角奶和肝脏织物,可以通过破碎进行性繁殖。 当植物的小块碎片断裂时,它可以形成一个新的植物。

    Reproduction in Nonvascular Seedless Plants
    ::非血管无种子植物的生殖

    Like all plants, have an alternation of generations life cycle. That means they alternate between diploid cell stages (having two sets of chromosomes) and haploid cell stages (having one set of chromosomes) during their life cycle. Recall the haploid stage is called the gametophyte , and the diploid stage is called the sporophyte .
    ::像所有植物一样,各代人寿命周期的交替。这意味着它们在其寿命周期中在低位细胞阶段(有两组染色体)和低位细胞阶段(有一套染色体)之间交替。回想起低位细胞阶段(有一套染色体 ) , 叫做 调色体, 低位细胞阶段被称为 色素。

    In the life cycle of the nonvascular seedless plants, the gametophyte stage is the longest part of the cycle. The gametophyte is the green photosynthetic carpet that you would recognize as a moss.
    ::在非血管无种子植物的生命周期中,游戏植物阶段是周期中最长的部分。游戏植物是绿色的光合作地毯,您将承认它为苔胱。

    The life cycle of nonvascular seedless plants can be described as follows:
    ::非血管无种子植物的生命周期可描述如下:

    1. The male gametophyte produces flagellated that must swim to the egg formed by the female gametophyte. For this reason, sexual reproduction must happen in the presence of water. Therefore, nonvascular plants tend to live in moist environments. Though the life of a nonvascular seedless plant is a cycle, this can be considered the initial step in the life cycle.
      ::由于这个原因,性生殖必须在水中发生。因此,非血管植物往往生活在潮湿的环境中。 尽管无血管种子植物的寿命是一个循环,但这可以被视为生命周期的第一步。
    2. Following , the sporophyte forms. The sporophyte is connected to, and dependent on, the gametophyte.
      ::之后是麻黄素形态。麻黄素与草药有关联,并依赖它。
    3. The sporophyte produces spores that will develop into gametophytes and start the cycle over again.
      ::脊髓灰质素会产生螺旋, 发展成草药, 并重新开始循环。

    Reproduction in Seedless Vascular Plants
    ::无种子血管植物的生殖

    For the seedless vascular plants , the sporophyte stage is the longest part of the cycle, but the cycle is similar to nonvascular plants. For example, in ferns , the gametophyte is a tiny heart-shaped structure, while the leafy plant we recognize as a fern is the sporophyte.
    ::对于没有种子的血管植物来说,植物是周期中最长的部分,但循环与非血管植物相似。 比如,在胎儿中,植物的组合体是一种微小的心形结构,而我们所认识的叶植物则是。

    The fern's sporangia , where spores are produced, are often on the underside of the fronds ( Figure ). Like nonvascular plants, ferns also have flagellated sperm that must swim to the egg. Unlike nonvascular plants, once fertilization takes place, the gametophyte will die, and the sporophyte will live independently.
    ::产出螺旋状物的股螺旋状状物通常位于顶部(Figure ) 。 与非血管植物一样,胎儿也有必须游到蛋头的挂状精子。 与非血管植物不同的是,一旦施肥,游戏植物就会死亡,脊椎动物也会独立生存。

    Underside of a fern frond showcasing sporangia where spores are produced.

    This fern is producing spores underneath its fronds.
    ::这只小鸟在它的羽毛下 生产着微粒

    The alternation of generations in ferns, detailing sporophyte and gametophyte stages.

    In ferns, the sporophyte is dominant and produces spores that germinate into a heart-shaped gametophyte.
    ::在胎儿体内,脊髓灰质素占主导地位,并产生发芽成心形草药的螺旋。

    Summary
    ::摘要

    • In nonvascular seedless plants, the gametophyte (haploid) stage is the longest part of the cycle.
      ::在无血管种子的植物中,植物植物(大麻)阶段是周期中最长的部分。
    • In seedless vascular plants, the sporophyte (diploid) stage is the longest part of the cycle.
      ::在没有种子的血管植物中,脊髓灰质素(分泌物)阶段是周期中最长的部分。

    Explore More
    ::探索更多

    Use the resource below to answer the questions that follow.
    ::利用以下资源回答以下问题。

    • Ferns-Pteridophyte Life Cycle at (12:30)
      ::Ferns-Pteridophite 生命周期(中午12:30)
    1. Where can the sorus on ferns be found?
      ::哪里可以找到青蛙的青蛙?
    2. What is found in the sorus?
      ::沙鲁里有什么发现?
    3. How is the mechanism that causes spores to be released similar to the mechanism that causes water to move up xylem? Explain your answer.
      ::造成螺旋释放的机制如何与造成水向上移动氧化氢的机制相类似?请解释您的答复。
    4. What is meant by a bisexual gametophyte?
      ::双性恋游戏植物是什么意思?
    5. What is the affect of the plant hormone antheridiogen? Why is this hormone crucial to ferns?
      ::植物激素乙酰胺原体的影响是什么?为什么这种激素对胎儿至关重要?

    Review
    ::回顾

    1. How do some seedless plants reproduce asexually?
      ::一些没有种子的植物是如何性繁殖的?
    2. What is alternation of generations?
      ::什么是世代的交替?
    3. Why must nonvascular plants live in moist environments?
      ::为什么非血管植物必须生活在潮湿的环境中?
    4. Compare and contrast the fern gametophyte and sporophyte.
      ::比较和对比 胎儿的游戏植物 和脊椎植物。