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  • General

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  • 核

    A police line with tape saying 'POLICE LINE DO NOT CROSS' near a crime scene.

     

    Where is your  ?
    ::哪里是你的吗?

    You may know that a criminal can easily leave DNA at a crime scene. How? DNA is found in every  cell  of your body. In each cell there is a nucleus, which is home to your DNA. So if a criminal has a cut, and   is left at the crime scene, or a hair falls out and is left behind, then DNA will also be left at the scene.
    ::你可能知道罪犯很容易在犯罪现场留下DNA。 如何? 在你身体的每一个细胞里都能找到DNA。 在每一个细胞里都有一个核, 这是你的DNA的家。 所以如果罪犯有切片, 留在犯罪现场, 或者头发掉出来, 被留下, 那么DNA也会留在现场。

    The Nucleus
    ::核心

    The  nucleus  is only found in  eukaryotic cells . It contains most of the  genetic material  (the  DNA ) of the cell. The genetic material of the nucleus is like a set of instructions. These instructions tell the cell how to build molecules needed for the cell to function properly. That is, the DNA tells the cell how to build molecules needed for life. The nucleus is surrounded by the  nuclear envelope , a double membrane (two  phospholipid  bilayers) that controls what goes in and out of the nucleus. The nucleus also has holes embedded in the nuclear envelope. These holes are known as  nuclear pores , and they allow things to flow in and out of the nucleus. 
    ::核核只存在于电解细胞中, 它包含细胞的大部分遗传物质( DNA) 。 核的遗传物质就像一套指令。 这些指令指示告诉细胞如何制造细胞正常运转所需的分子。 也就是说, DNA告诉细胞如何制造生命所需的分子。 核环绕着核封套, 一个控制核进出的双膜( 两个磷素双层) 。 核核芯中也有嵌入核信封的洞。 这些洞被称为核孔, 它们允许物质流进和流出核芯。

    Chromosomes
    ::染色体

    Inside of the nucleus, you will find the  chromosomes . Chromosomes are strands of DNA wrapped around  proteins . They contain  genes , or small units of genetic material (DNA) that contains the code for the creation of a protein. Human cells have 46 chromosomes (23 pairs). There are hundreds to thousands of genes on each chromosome. 
    ::在核内,你会发现染色体。染色体是围绕蛋白质包裹的DNA链条。它们包含基因,或含有蛋白质生成代码的少量遗传物质(DNA)。人类细胞有46种染色体(23对)。每个染色体上都有数百到数千个基因。

    Nucleolus
    ::核核核列

    The nucleus of many cells also contains a central region called the  nucleolus . The job of the nucleolus is to build  ribosomes . These ribosomes flow out the nuclear pores into the  cytoplasm .  Ribosomes  are   that make proteins in the cytoplasm. See the composition of the nucleus pictured below ( Figure   ).
    ::许多细胞的核心也包含一个称为核子的中央区域。核子的功用是建立核子。这些核子的核子将流出核孔,进入细胞图层。Ribocomes是细胞图层中蛋白质的产物。请看下面的核子的构成(图 ) 。

    The structure of a nucleus with labels for nucleolus and nuclear envelope.

     

    In eukaryotic cells, the DNA is kept in the nucleus. The nucleus is surrounded by a double membrane called the nuclear envelope, with nuclear pores embedded. Within the nucleus is the nucleolus.
    ::在eukaryatic细胞中,DNA保存在核核中。核中环绕着一个叫做核包的双膜,并嵌入核孔。核中是核子。

    Summary
    ::摘要

    • The nucleus contains the genetic material of the cell.
      ::核心含有细胞的遗传物质
    • The genetic material of the cell is found in chromosomes, DNA wrapped around proteins.
      ::细胞的遗传物质在染色体中发现,DNA围绕蛋白质包裹。
    • The nucleolus, which makes ribosomes, is also within the nucleus.
      ::核核糖核素 产生核糖核素 也存在于核核中

    Explore More
    ::探索更多

    Use the resources below to answer the following questions.
    ::利用以下资源回答下列问题。

    • Nucleus  at   (2:25)

      ::核心值(2:25)
    1. What is chromatin? What molecules make up chromatin?
      ::什么是染色体?什么是染色体?什么分子构成染色体?
    1. What is the nuclear membrane? What kind of membrane is this membrane?
      ::核膜是什么?
    1. What is the nucleolus? What molecules do you find there?
      ::核核素是什么?
    1. How is the inside of the nucleus connected to the cytosol? Why is this connection vital for the cell?
      ::核的内核是如何与细胞索相连的?为什么这一连接对细胞至关重要?

    Review
    ::回顾

    1. What is contained in the nucleus of a cell?
      ::细胞核心中含有什么?
    1. What is a chromosome? Where are chromosomes located?
      ::什么是染色体?
    1. How many chromosomes do humans have?
      ::人类有多少染色体?
    1. What is the function of the nucleolus?
      ::核糖核糖核糖核糖核糖核酸的功能是什么?