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  • 非男性继承人继承权

    Red blood cells in a bloodstream, highlighting blood type complexity.

    How would Mendel explain ?
    ::门德尔怎么解释?

    The inheritance of traits is not always as simple as Mendel's rules. Each characteristic Mendel investigated was controlled by one gene that had only two possible alleles , one of which was completely dominant over the other. We now know that inheritance is often more complicated than this. In blood types, for example, there are actually three alleles instead of two. And some traits even have more than three alleles.
    ::特质的继承并不总是像门德尔的规则那么简单。 所调查的曼德尔的每个特征都由一个基因控制,这个基因只有两个可能的异长,其中一个完全高于另一个。我们现在知道,继承往往比这个复杂得多。例如,在血型中,实际上有三个异长,而不是两个。有些特性甚至有三个以上的异长。

    Exceptions to Mendel's Rules
    ::门德尔规则例外

    In all of Mendel’s experiments , he worked with traits where a single gene controlled the trait. Each also had one allele that was always dominant over the recessive allele . But this is not always true.
    ::在孟德尔的所有实验中,他都研究单一基因控制特性的特性。 每个人的基因都有一个等离子,它总是凌驾于休眠的等离子之上。 但这并不总是真实的。

    There are exceptions to Mendel’s rules, and these exceptions usually have something to do with the dominant allele . If you cross a homozygous red flower with a homozygous white flower, according to , what color flower should result from the cross? Either a completely red or completely white flower, depending on which allele is dominant. But since Mendel's time, scientists have discovered this is not always the case.
    ::门德尔规则有例外,这些例外通常与占支配地位的花朵有关。 如果你穿过一朵同质的红花和一朵同质的白花,那么十字架应该产生什么颜色的花? 要么是一朵完全红花,要么是一朵完全白花,这取决于哪朵同质的花朵占主导地位。 但是,自从曼德尔时代以来,科学家们发现这种情况并非总是如此。

    Incomplete Dominance
    ::不完全占多数

    One allele is NOT always completely dominant over another allele. Sometimes an individual has a phenotype between the two parents because one allele is not dominant over another. This pattern of inheritance is called incomplete dominance . For example, snapdragon flowers show incomplete dominance. One of the genes for flower color in snapdragons has two alleles, one for red flowers and one for white flowers.
    ::一种异种并不总能完全支配另一种异种。 有时,一个人在双亲之间有一种同系物类型,因为一种异种并不在另一种异种中占主导地位。 这种继承模式被称为不完全主导。 比如,松鼠花表现出不完全主导。 松鼠花的其中一个基因在松鼠花色中有两个异种,一个是红花,另一个是白花。

    A plant that is homozygous for the red allele ( RR ) will have red flowers, while a plant that is homozygous for the white allele will have white flowers ( WW ). But the heterozygote will have pink flowers ( RW ) ( Figure ) as both alleles are expressed. Neither the red nor the white allele is dominant, so the phenotype of the offspring is a blend of the two parents.
    ::一种为红线(RR)配种的植物将拥有红花,而一种为白线(WW)配种的植物将拥有白花(WW)。 但异体zygote将拥有粉红色花(RW)(图),因为这两种花(RW)(图 ) 的表达方式都是粉红色花(RW)(图 ) 。 红线和白线(RR)都不占主导地位,因此后代的苯型是双亲的混合体。

    Pink snapdragon flowers illustrating incomplete dominance in plant genetics.
    Pink snapdragons are an example of incomplete dominance.

    Another example of incomplete dominance is with sickle cell anemia , a disease in which a protein called hemoglobin is produced incorrectly. This causes the red blood cells to have a sickle shape, making it difficult for these misshapen cells to pass through the smallest . A person that is homozygous recessive ( ss ) for the sickle cell trait will have red blood cells that all have the incorrect hemoglobin. A person who is homozygous dominant ( SS ) will have normal red blood cells.
    ::另一个不完全占优势的例子是镰状细胞贫血,这种疾病不正确地产生了一种叫血红蛋白的蛋白,这导致红细胞有镰状形状,使这些小细胞难以穿透最小的细胞。对于镰状细胞特征来说具有同质性休眠性的人将拥有红色血红细胞,所有细胞都有不正确的血红蛋白。对于同质人来说,具有支配地位的人将拥有正常的红细胞。

    What type of blood cells do you think a person who is heterozygous ( Ss ) for the trait will have? They will have some misshapen cells and some normal cells ( Figure ). Both the dominant and recessive alleles are expressed, so the result is a phenotype that is a combination of the recessive and dominant traits .
    ::你认为异体性格细胞(Ss)会有什么类型的血细胞?它们会有一些细胞和正常细胞(图 ) 。 主导和闭塞的异象都会被表达出来, 因此结果是一种细胞型, 即休眠和主要特征的组合。

    Comparison of normal and sickle-shaped red blood cells illustrating incomplete dominance.
    Sickle cell anemia causes red blood cells to become misshapen and curved unlike normal, rounded red blood cells.

    Codominance
    ::共居情况

    Another exception to Mendel's laws is a phenomenon called codominance . For example, our blood type shows codominance. Do you know what your blood type is? Are you A? O? AB? Those letters actually represent alleles. Unlike other traits, your blood type has three alleles, instead of two!
    ::孟德尔法律的另一个例外是所谓的共产主义现象。 例如, 我们的血型表现出共产主义。 你知道你的血型是什么吗? A? O? AB? 这些字母实际上代表了异性。 与其他特性不同, 您的血型有三个异性, 而不是两个异性 。

    The ABO blood types ( Figure ) are named for the protein attached to the outside of the blood cell. In this case, two alleles are dominant and completely expressed (I A and I B ), while one allele is recessive (i). The I A allele encodes for red blood cells with the A antigen , while the I B allele encodes for red blood cells with the B antigen. The recessive allele (i) does not encode for any proteins. Therefore a person with two recessive alleles (ii) has type O blood. As no dominant (I A and I B ) allele is present, the person cannot have type A or type B blood. What are the genotypes of a person with type A or type B blood?
    ::ABO 血型( 图表) 命名为与血液细胞外部相连的蛋白质。 在这种情况下, 两种所有元素( IA 和 IB) 具有支配性和完全表达性, 而一种是隐性( i) 。 IA alle 的红血细胞编码与 A 抗原有关, 而 IB 的红血细胞编码与 B 抗原有关。 隐性血型( i) 并不编码任何蛋白。 因此, 有两种隐性外延( ii) 的人有O 型血 。 由于不存在支配性( IA 和 IB) , 人不能有 A 或 B 型血型 。 A 或 B 型血型的人的基因类型是什么 ?

    Inheritance patterns of ABO blood types illustrating codominance and genotypes.
    An example of codominant inheritance is ABO blood types.

    There are two possible genotypes for type A blood, homozygous ( I A I A ) and heterozygous ( I A i ), and two possible genotypes for type B blood, ( I B I B and I B i ). If a person is heterozygous for both the I A and I B alleles, they will express both and have type AB blood with both proteins on each red blood cell.
    ::A型血液有两种可能的基因型,即同质吸血(IAIA)和异质吸血(IAi),B型血液有两种可能的基因型(IBIB和IBI),如果一个人是IA和IB等血源的异质吸血种,他们将同时表达两种情况,并且在每个红血细胞上含有两种蛋白质的AB型血液。

    This pattern of inheritance is significantly different than Mendel’s rules for inheritance, because both alleles are expressed completely, and one does not mask the other.
    ::这种继承模式与Mendel的继承规则大不相同,因为两者都是完全表达的,两者不掩盖对方。

     

     

    Summary
    ::摘要

    • Incomplete dominance, as seen in sickle cell anemia, is a form of inheritance in which one allele is only partly dominant over the other allele, resulting in an intermediate phenotype.
      ::从镰状细胞贫血中可以看出,不完全占支配地位是一种继承形式,其中一人只能部分支配另一人,造成中间苯型。
    • Codominance, as in human blood type, is a form of inheritance in which both alleles are expressed equally in the phenotype of the heterozygote.
      ::同人类血型一样,共同占优势是一种继承形式,在这种继承形式中,异体zygote的苯型以等同的方式表示。

    Review
    ::回顾

    1. A dark purple flower is crossed with a white flower of the same species, and the offspring have light purple flowers. What type of inheritance does this describe? Explain.
      ::黑色紫色花朵与同种白花相交叉,后代则有浅紫色花朵。这里描述的是哪种继承?请解释。
    2. What is the inheritance pattern in which both alleles are expressed?
      ::以什么遗产模式来表述这两种所有物?
    3. What is the genotype of a person with type O blood?
      ::有O型血的人的基因型是什么?
    4. What is the genotype(s) of a person with type AB blood?
      ::乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙型乙