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  • 与性别挂钩的继承权

    Two cartoon babies: one swaddled in pink and another in blue, illustrating gender differences.

    Male or female?
    ::男性还是女性?

    One of the exciting things about expecting a child is wondering if the baby will be a boy or a girl. There are many superstitions about how one might influence or predict the outcome. But what really determines if a baby is male or female? We now know that the gender of a baby is determined by a special pair of chromosomes known as the sex chromosomes .
    ::生孩子的令人兴奋之处之一是想知道孩子是男孩还是女孩。人们对于如何影响或预测结果有很多迷信。但真正决定一个婴儿是男性还是女性是什么?我们现在知道一个婴儿的性别是由一对特殊的染色体决定的,即所谓的性染色体。

    Sex-linked Inheritance
    ::与性别挂钩的继承权

    What determines if a baby is a male or female? Recall that you have 23 pairs of chromosomes—and one of those pairs is the sex chromosomes . Everyone has two sex chromosomes. Your sex chromosomes can be X or Y. Females have two X chromosomes (XX), while males have one X chromosome and one Y chromosome (XY).
    ::婴儿是男性还是女性呢?你应当记得,你有23对染色体——其中一对是性染色体。每个人都有两个性染色体。你的性染色体可以是X,也可以是Y。女性有2个X染色体(XX),而男性有1个X染色体和1个Y染色体(XY)。

    If a baby inherits an X chromosome from the father and an X chromosome from the mother, what will be the child’s sex? The baby will have two X chromosomes, so it will be female. If the father’s carries the Y chromosome, the child will be male. Notice that a mother can only pass on an X chromosome, so the sex of the baby is determined by the father. The father has a 50 percent chance of passing on the Y or X chromosome, so there is a 50 percent chance that a child will be male, and there is a 50 percent chance a child will be female. This 50:50 chance occurs for each baby. A couple's first five children could all be boys. The sixth child still has a 50:50 chance of being a girl.
    ::如果婴儿从父亲那里继承X染色体,从母亲那里继承X染色体,那么孩子的性别会是什么?婴儿将有两个X染色体,因此将是女性。如果父亲携带Y染色体,孩子将是男性。注意母亲只能通过X染色体,因此婴儿的性别由父亲决定。父亲有50%的通过Y或X染色体的机会,因此,孩子有50%的通过机会是男性,孩子有50%的通过机会是女性。每个孩子都有50:50的机会。一对夫妇的前五个孩子都可能是男孩。第六个孩子仍然有50:50成为女孩的机会。

    One special pattern of inheritance that doesn’t fit Mendel’s rules is sex-linked inheritance , referring to the inheritance of traits that are located on genes on the sex chromosomes. Since males and females do not have the same sex chromosomes, there will be differences between the sexes in how these sex-linked traits —traits linked to genes located on the sex chromosomes—are expressed. Sex-linked traits usually refer to traits due to genes on the X chromosome.
    ::一种不符合Mendel规则的特殊继承模式是与性别相关的继承,指的是性染色体基因上的遗传特征的继承。 由于男性和女性没有相同的性别染色体,这些与性别相关的特征 — — 与性染色体上的基因相联系的三角形 — — 的表达方式在两性之间会有差异。 与性别相关的特征通常是指X染色体上的基因特征。

    One example of a sex-linked trait is red-green color blindness . People with this type of color blindness cannot tell the difference between red and green. They often see these colors as shades of brown ( Figure ). Boys are much more likely to be colorblind than girls ( Table ). This is because color blindness is a sex-linked , recessive trait.
    ::与性别相关特征的一个例子是红绿色失明。有这种肤色失明的人无法辨别红色和绿色之间的区别。他们往往将这些颜色视为棕色的遮光(图示 ) 。男孩比女孩更有可能是色盲(表 ) 。这是因为肤色失明是一种与性别相关、隐性特征。

    Boys only have one X chromosome, so if that chromosome carries the gene for color blindness, they will be colorblind. As girls have two X chromosomes, a girl can have one X chromosome with the colorblind gene and one X chromosome with a normal gene for color . Since color blindness is recessive, the dominant normal gene will mask the recessive colorblind gene. Females with one color blindness allele and one normal allele are referred to as carriers . They carry the allele but do not express it.
    ::男孩只有一个X染色体,所以如果染色体带有色盲基因,他们就是色盲。因为女孩有两个X染色体,女孩可以拥有一个带有色盲基因的X染色体,而一个带有正常肤色基因的X染色体。由于色盲是休眠性的,占支配地位的正常基因将掩盖隐性色盲基因。带有一种色盲的雌性异性与普通异性被称为载体。它们携带异性,但不表示。

    How would a female become colorblind? She would have to inherit two genes for color blindness, which is very unlikely. Many sex-linked traits are inherited in a recessive manner.
    ::女性如何成为色盲?她必须继承两种色盲基因,这不太可能。 许多与性别相关的特征都是以暂时性的方式继承的。

    Image depicting colored dots illustrating red-green color blindness perception difficulty.
    A person with red-green color blindness would not be able to see the number.
      X c X
    X

    X c X
    ::Xcxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

    (carrier female)
    :sad载体女性)

    XX
    ::XX 二十

    (normal female)
    :sad正常女性)

    Y

    X c Y
    ::XcY XcY XcY XcY XcY XcY XcY XcY XcY XcY XcY XcY

    (colorblind male)
    :sad色盲男性)

    XY
    ::XY 时

    (normal male)
    :sad正常男性)

    According to this ( Table ), the son of a woman who carries the color blindness trait and a male with normal vision has a 50% chance of being colorblind.
    ::根据这个表(表),带有色盲特征和有正常视力的男性的女子的儿子50%是色盲。

    Summary
    ::摘要

    • Each individual has two sex chromosomes; females have two X chromosomes (XX), while males have one X chromosome and one Y chromosome (XY).
      ::每个人有2种性染色体;女性有2种X染色体(XX),男性有1种X染色体和1种Y染色体(XY)。
    • Sex-linked traits are located on genes on the sex chromosomes.
      ::性染色体上的基因具有与性有关的特性。

    Explore More
    ::探索更多

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

    Explore More I
    ::探索更多

    • Sex-linked Traits at (5:16)
      ::5:16时(5:16)与性别有关的轨迹

     

     

    1. What was unusual about the F 2 generations in Morgan's crosses?
      ::摩根十字架上的F2世代有什么不寻常?
    2. According to Morgan, where is the gene for eye color located?
      ::Morgan说眼色基因在哪里?
    3. How did Morgan test his hypothesis on the location of the eye color gene?
      ::Morgan如何测试他的假说 关于眼色基因的位置?
    4. What are three traits that humans have that are related to genes exclusive to the X-chromosome?
      ::人类的三种特征 与X染色体的基因有关吗?

    The "Morgan" referred to in the above clip is Thomas Hunt Morgan. You can find out more about him and his work here: .
    ::上面提到的"摩根"是托马斯·亨特·摩根。

    Explore More II
    ::探索更多情况二

    • Inheritance of Sex-linked Traits at (4:49)
      ::在4:49时继承与性有关的悲剧(4:49)

     

     

    1. What are the three types of color blindness? How are they caused?
      ::这三种颜色失明是什么?
    2. What is the "Law of Dominance"?
      ::什么是"统治法"?
    3. Can a woman have color blindness if her father does not? Explain your answer fully.
      ::如果父亲没有,女人就不能有色盲吗?
    4. A woman is color blind but her sister isn't. What does that tell you about their parents
      ::女人是色盲,但妹妹不是

    Review
    ::回顾

    1. What are the sex chromosomes of a male and a female?
      ::男性和女性的性染色体是什么?
    2. Explain why the father determines the sex of the child.
      ::解释为什么父亲决定孩子的性别。
    3. What is sex-linked inheritance?
      ::什么是与性别挂钩的继承?
    4. A son cannot inherit color blindness from his father. Why not?
      ::儿子不能继承父亲的肤色失明,为什么不呢?