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  • General

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  • 有丝分裂

    Colorful representation of chromosomes, highlighting their structure during cell division.

     

    How is your   organized?
    ::你的组织如何?

    Your DNA is organized into  chromosomes , the pink structures pictured above. Your DNA doesn't always look so pretty, though. It only winds tightly into chromosomes when the  cell  is getting ready to divide. If your DNA wasn't organized into chromosomes, your DNA would look like a mass of strings and would be difficult to divide up!
    ::您的DNA组织成染色体, 上面所描绘的粉红色结构。 您的DNA并不总是看起来那么漂亮, 不过。 只有当细胞准备分解时, DNA才会紧紧地飞向染色体 。 如果您的DNA没有组织成染色体, 您的DNA将看起来像一团绳子, 并且很难分开 !

    Mitosis and Chromosomes
    ::传染病和染色体

    The genetic information of the cell, or DNA, is stored in the  . During  mitosis , two nuclei (plural for nucleus) must form, so that one nucleus can be in each of the new cells after the cell divides. In  order  to create two genetically identical nuclei, DNA inside of the nucleus must be copied or replicated. This occurs during the S phase of the  . During mitosis, the copied DNA is divided into two complete sets, so that after  cytokinesis , each cell has a complete set of genetic instructions.
    ::细胞的遗传信息, 或DNA, 储存在 。 在分裂过程中, 需要形成两个核( 核的圆柱体) , 这样在细胞分裂后, 每一个新细胞中都可以有一个核。 为了创建两个基因相同的核, 核内的DNA必须复制或复制。 这在 S 阶段发生 。 在分裂过程中, 复制的DNA将分为两个完整的组, 这样在细胞分裂后, 每个细胞都有一套完整的基因说明 。

    Chromosomes
    ::染色体

    To begin mitosis, the DNA in the nucleus wraps around  proteins  to form  chromosomes . Each  organism  has a unique number of chromosomes. In human cells, our DNA is divided up into 23 pairs of chromosomes. Replicated DNA forms a chromosome made from two identical  sister chromatids , forming an "X" shaped  molecule  ( Figure   ). The two chromatids are held together on the chromosome by the  centromere . The centromere is also where  spindle   fiber  microtubules attach during mitosis. The  spindles  separate sister chromatids from each other.
    ::为了开始分解, 核中的DNA围绕蛋白质环绕着DNA环绕着蛋白质组成染色体。 每个生物体都有独特的染色体数。 在人类细胞中, 我们的DNA分为23对染色体。 复制的DNA形成由两个相同的姐妹染色体组成的染色体, 形成一个“ X” 形状的分子( Figure ) 。 两种染色体由丙烯( centromere) 将染色体放在染色体上。 丙烯( centromere) 也是在线状体中附着脊椎纤维微细胞的。 脊椎将姐妹染色体分开 。

    DNA coiling to form chromosomes, highlighting centromere and chromatid structure.

     

    The DNA double helix wraps around proteins (2) and tightly coils a number of times to form a chromosome (5). This figure shows the complexity of the coiling process. The red dot shows the location of the centromere, which holds the sister chromatids together and is where the spindle microtubules attach during mitosis and meiosis. Notice that a chromosome resembles an "X."
    ::DNA双螺旋围绕蛋白质(2)环绕双螺旋环绕着双螺旋,并多次紧绕圈圈以形成染色体(5)。 这个图示显示了调合过程的复杂性。 红色点显示的是将姊妹染色体放在一起的丙色米尔的位置, 并且是脊椎微图象在分裂和 meisis 中附着的地方。 请注意, 染色体类似于“ X ” 。

    Four Phases of Mitosis
    ::四个阶段的消化系统

    During mitosis, the two sister chromatids must be divided. This is a precise process that has four individual phases to it. After the sister chromatids separate, each separate chromatid is now known as a chromosome. Each resulting chromosome is made of DNA from just one chromatid. So, each chromosome after this separation is made of "1/2 of the X." Through this process, each  daughter cell  receives one copy of each chromosome. The four phases of mitosis are  prophase ,  metaphase ,  anaphase  and  telophase  ( Figure   ).
    ::在分裂过程中, 需要将两个姐妹染色体分开。 这是一个精确的过程, 它有四个不同的阶段。 在姐妹染色体分离后, 每个单独的染色体现在都被称为染色体。 每个结果的染色体是由一个染色体的DNA制成的。 因此, 分离后的每个染色体都是“ X 的 1/2 ” 。 通过这个过程, 每个女儿细胞都收到每个染色体的复制件。 分裂的四个阶段是前期、 后期、 周期和调频( 图示 ) 。

    1. Prophase : The chromatin, which is unwound DNA, condenses forming chromosomes. The DNA becomes so tightly wound that you can see them under a  . The membrane around the nucleus, called the nuclear envelope, disappears. Spindles also form and attach to chromosomes to help them move.
      ::预期: 染色体,即不响的DNA,会凝结形成染色体。 DNA会变得非常密切的伤口, 以至于你可以看到它们在一个核下。 核心周围的膜, 叫做核信封, 消失了。 Spindles 也形成并附着于染色体, 帮助他们移动 。
    1. Metaphase : The chromosomes line up in the center, or the equator, of the cell. The chromosomes line up in a row, one on top of the next.
      ::元阶段 : 染色体排在细胞的中心, 或者赤道。 染色体排在一排, 排在下一排的顶端 。
    1. Anaphase : The two sister chromatids of each chromosome separate as the spindles pull the chromatids apart, resulting in two sets of identical chromosomes.
      ::分析阶段:每个染色体的两姐妹染色体在脊椎拉开染色体时分离,产生两组相同的染色体。
    1. Telophase : The spindle dissolves and nuclear envelopes form around the chromosomes in both cells.
      ::电磁波:两细胞的染色体周围都有脊椎溶解和核封套。

    Cycle of cell division showing phases of mitosis: prophase, metaphase, anaphase, telophase.

     

    An overview of the cell cycle and mitosis: during prophase the chromosomes condense, during metaphase the chromosomes line up, during anaphase the sister chromatids are pulled to opposite sides of the cell, and during telophase the nuclear envelope forms.
    ::细胞循环和分裂症概览:在前期,染色体凝结,在元期,染色体排成,在前期,姐妹染色体被拉到细胞的对面,在调频期间,核信封表格被拉动。

    After telophase, each new nucleus contains the exact same number and type of chromosomes as the original cell. The cell is now ready for cytokinesis, which literally means "cell movement." During cytokinesis, the  cytoplasm  divides and the  parent cell  separates, producing two genetically identical cells, each with its own nucleus. A new   forms and in plant cells, a  cell wall  forms as well. Below is a representation of dividing plant cells ( Figure   ).
    ::调子后, 每个新核都含有与原始细胞完全相同的染色体数量和类型。 细胞现在可以使用细胞基尼, 这实际上意味着“ 细胞运动 ” 。 在细胞基尼, 细胞基质分裂和母细胞分离, 产生两个基因相同的细胞, 每个细胞都有自己的核。 一种新形式, 在植物细胞中, 一种细胞壁形式。 下面是分解植物细胞的表示( Figure ) 。

    Illustration shows various stages of mitosis in plant cells, highlighting cell division process.

     

    This is a representation of dividing plant cells. Cell division in plant cells differs slightly from animal cells as a cell wall must form. Note that most of the cells are in interphase. Can you find examples of the different stages of mitosis?
    ::这是分解植物细胞的表示。 植物细胞的细胞分裂与动物细胞略有不同, 因为细胞壁必须形成。 请注意, 大部分细胞处于中间阶段。 您能找到不同阶段的分裂化的例子吗 ?

    Summary
     ::摘要

    • The DNA in the nucleus wraps around proteins to form chromosomes.
      ::核中的DNA环绕蛋白质 形成染色体
    • During mitosis, the newly duplicated chromosomes are divided into two daughter nuclei.
      ::在分裂期间,新复制的染色体分为两个女儿核。
    • Mitosis occurs in four phases, called prophase, metaphase, anaphase, and telophase.
      ::疾病分四个阶段发生,称为前期、后期、前期和后期。

    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。

    • Mitosis  by NDSU VCell Productions at   (6:10)
      :sad6:10)通过NDSU VCell 生产厂进行吸收(6:10)
    1. When does the "classic" chromosome structure of DNA appear during mitosis?
      ::DNA的“古典”染色体结构 何时出现在分裂症中?
    1. What problems do you think might arise if the chromosomes did not align during metaphase?
      ::你认为如果染色体在元阶段时不匹配 会产生什么问题?
    1. When do the nuclear envelopes reform? What problems might arise if a cell started forming the nuclear envelopes earlier?
      ::核封套何时改革? 如果一个细胞早些时候开始形成核封套,会有什么问题?
    1. In what stage do cells spend most of their "life"?
      ::细胞在什么阶段能花掉大部分的"生命"呢?
    1. How long does mitosis take in the typical eukaryotic cell?
      ::在典型的表情细胞里 分裂需要多长时间?

    Review
    ::回顾

    1. What are chromosomes?
      ::什么是染色体?
    1. What are the four phases of mitosis, in the correct order?
      ::脊髓灰质疏松的四个阶段是什么? 正确的顺序?
    1. In what phase of mitosis are chromosomes moving toward opposite sides of the cell?
      ::染色体在分裂症的哪个阶段向细胞的对面移动?
    1. Compare the two nuclei that form as a result of mitosis?
      ::比较两块核 由分裂症形成?
    1. What is cytokinesis, and when does it occur?
      ::什么是细胞基质,何时发生?