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  • General

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  • 分子遗传 - 高级

    Chromosome, Gene, Locus, and Allele.

    Chromosome, gene, locus, and allele: what's the difference?
    ::染色体、基因、病原体和Alele:有什么区别?

    , gene , locus and are all related. What is the difference between a gene and a locus? Between a gene and an allele? Chromosomes are composed of genes located at specific loci. And genes have different alleles. If genes did not have different alleles, we would genetically be all the same. What does that mean?
    ::基因和病原体之间有什么区别?基因和病原体之间有什么区别?基因和病原体之间有什么区别?染色体是由特定地方的基因组成。基因有不同的病原体。如果基因没有不同的病原体,我们基因会是一样的。这是什么意思?

    Mendelian Theory and Molecular Genetics
    ::门德勒理论和分子遗传学

    was perhaps lucky in that the characteristics he chose to study in the had a relatively simple pattern of inheritance. These characteristics were determined by one gene for which there were exactly two alleles . One of these alleles was dominant and the other recessive . Had any of these characteristics been determined by more than one gene, he may not have been able to develop such amazing insight into inheritance. Unknowingly, he also analyzed characteristics that were not linked, that is, there were not inherited together; the inheritance of one trait did not effect the inheritance of any other trait. Keep in mind that Mendel did not know of , chromosomes, genes, loci or alleles, and described his findings in terms of heritable factors. Nor did he know of or linked genes .
    ::幸运的是,他选择在继承模式相对简单的情况下研究这些特征,这些特征是由一个基因决定的,其中两个异种完全相同。其中一个异种占主导地位,而另一个则处于休眠状态。如果这些特征中任何一个都由一个以上的基因决定,他可能无法对继承形成如此惊人的洞察力。他在不知情的情况下还分析了没有联系的特征,即没有共同继承;一个异种的遗传并不影响任何其他特性的继承。铭记Mendel并不了解染色体、基因、异种、异种或异种,并用遗传因素来描述他的调查结果。他也不知道或联系基因。

    In many instances, the relationship between genes and inheritance is more complex than that which Mendel found. Nevertheless, geneticists have since found that Mendel’s findings can be applied to many organisms . For example, there are clear patterns of in humans. These include the inheritance of normal characteristics and characteristics that occur less often. Easily observable Mendelian traits in humans include free ear lobes (in most people the ear lobes hang free (dominant), whereas the attached earlobe is recessive), hitchhiker's thumb (a straight thumb is dominant, while a bent thumb is recessive), widow's peak (a hairline with a distinct point in the middle of the forehead is dominant, while a straight hairline is recessive), dimpled chin (a cleft in the chin is dominant, whereas the absence of a cleft is recessive), and mid-digital hair (hair on any middle segments of the fingers is dominant). Of course, many severe human phenotypes are inherited in a Mendelian fashion including Phenylketonuria (PKU), cystic fibrosis , Huntington's disease, hypercholesterolemia, and sickle-cell anemia . These are termed and will be discussed in additional concepts.
    ::在许多情况下,基因和继承之间的关系比Mendel发现的情况复杂得多。然而,遗传学家发现Mendel的发现可以适用于许多生物。例如,人类中存在明显的模式。其中包括正常特征和特征的继承,而通常的特征往往较少发生。在人类中容易观察到的Mendelian特征包括自由耳叶叶(在大多数人中耳叶悬浮(占主位),而附随的耳垂是歇息的),搭便士的拇指(直拇指占主导地位,而弯拇指占居主导地位),遗孀的峰值(前额中间有明显点的发线为主导地位,而直发线为休居地位),下巴(下巴裂痕占主导地位,而左臂则占主导地位)和中位发型(手指中任何部部分的头发占主导地位 ) 。 当然, 许多严重的人体型(直拇指占主导地位,而弯拇指占主导地位 ) , 遗孀的峰(前额则占主导地位) ) , 遗孀的峰(直线为主导地位, ) ) , , 遗孀的峰(直指为占主导地位(直线, 而前额是占主导地位, ) , 而前额则占主导地位为主, ) , 、直发直发直线为主的发直线为主的发直线为主 ) ) ) ) ) 、 、 、 、 、 下部为主 、 、 下部为主 、 下部为主 、 、 、 、 、 、 、 、 下部 下部为 下部为主 下部为主 、 、 下部 下部为 下部 下部 下部 、 、 、 、 、 、 、 、 下部 下部 下部 下部为 下部 下部 下部为 下部 下部 下部 下部 下部 下部 、 、 、 下部 下部 下部系 下部 下部 下部 、 、 、 下部 下部 、 、 、

    Dominant and Recessive Alleles
    ::支配和消退

    Mendel used letters to represent dominant and recessive factors. Likewise, geneticists now use letters to represent alleles. Capital letters refer to dominant alleles , and lowercase letters refer to recessive alleles . For example, the dominant allele for the trait of green pod color is indicated by G . The recessive trait of yellow pod color is indicated by g . A true-breeding plant for green pod color would have identical alleles GG in all its somatic . Likewise, a true-breeding plant for yellow pod color would have identical alleles gg in all of its somatic cells. During gamete formation, each gamete receives one copy of an allele. When occurs between these plants, the offspring receives two copies of the allele, one from each parent. In this case, all of the offspring would have two different alleles, Gg , one from each of its parents.
    ::门德尔用字母代表支配性和消亡性因素。 类似地, 基因学家现在使用字母代表 alleles 。 资本字母指占支配地位的 alleles, 小写字母指居室的 alleles 。 例如, G 表示绿色播客颜色特征的支配性偏差。 G 表示黄色播客颜色的消亡性特征。 g 表示绿色播客颜色的纯种植物在其所有体型中都有相同的GGG。 同样, 黄色播客颜色的真种植物在其所有体细胞中都有相同的Alees gg 。 在游戏形成期间, 每个网友都会收到一份Aleele。 当这些植物之间发生时, 后代会收到两份Alee, 每个父母一份。 在这种情况下, 所有后代都会有两种不同的Ale, Gg, 每个父母一份 。

    An organism that has an identical pair of alleles for a trait is called homozygous . The true-breeding parents GG and gg are homozygous for the pod color gene. Organisms that have two different alleles for a gene are called heterozygous ( Gg ). The offspring of the cross between the GG (homozygous dominant) and gg (homozygous recessive) plants are all heterozygous for the pod color gene. A homozygous individual is known as a homozygote , and a heterozygous individual is known as a heterozygote . Due to dominance and recessiveness of alleles, an organism’s traits do not always reveal its genetics . Therefore, geneticists distinguish between an organism’s genetic makeup, called its genotype , and its physical traits, called its phenotype . For example, the GG parent and the Gg offspring have the same phenotype (green pods) but different genotypes. An organism's genotype results in an organism's phenotype. For example, if your dog has black hair, you cannot easily tell its genotype (that would take some scientific analysis), but you can easily tell its phenotype.
    ::一种具有相同特性的异象的有机体称为同质基因。真正的双胞胎父母GG和gg是同质基因的同质基因。对于一种基因来说,有两种不同的异质基因的同质基因。对于一种基因来说,有两种不同的异质异质的有机体被称为异质象(Gg ) 。因此,基因学家区分一种生物的基因结构,称为它的基因型,和它的物理特征,称为它的苯型。例如,同质基因人的个人被称为同质动物,而异质虫人则被称为异质酶人。由于异质基因的支配性和消亡性,一种生物的特性并不总是能揭示它的基因特征。因此,基因学家区分一种生物体的基因结构,称为它的基因型,它的物理特征,称为它的基因型。例如,GG和G组的后代很容易看出同一种同型的同型(绿形的相),但是不同的基因型个人也被称为异异异异型的异性基因。由于异性生物体的支配性和消亡体型的基因型,因此,它的基因型的基因型的基因型分析不能轻易地反映它的基因型的基因。如果它的基因型,那么,它的基因型的基因型的基因型的基因型的基因型分析,它会研究会研究会研究会研究会研究会研究会会以象型的基因型的基因型的基因型能会分析。

    Summary
    ::摘要

    • Mendelian inheritance patterns can be seen in humans. Albinism is a genetic disorder that is inherited as a simple Mendelian trait.
      ::白化病是一种遗传障碍,作为单纯的门德利特征而继承。
    • Genotype determines phenotype. A homozygous dominant or a heterozygous genotype will always show a dominant phenotype. A homozygous recessive genotype can only show a recessive phenotype.
      ::基因类型决定了苯型。 支配性同正古或异正正古或异正古的基因类型将总是显示主要苯型。 单正古的基因类型只能显示阴性同正。

    Review
    ::回顾

    1. Relate the term homozygous to heterozygous by using an example from Mendel’s experiments.
      ::使用Mendel实验中的例子,
    2. Relate the term genotype to phenotype by using an example from Mendel’s experiments.
      ::使用Mendel实验中的一个例子,将基因型与苯型相对应。
    3. Why can’t you always identify the genotype of an organism from its phenotype?
      ::为何不能总是从基因型中辨别生物体的基因型?
    4. Explain Mendel’s laws in genetic terms, that is, in terms of chromosomes, genes, and alleles.
      ::解释Mendel在遗传学方面的法律, 即染色体、基因和蛋白。
    5. If Darwin knew of Mendel’s work, how might it have influenced his theory of evolution? Do you think this would have affected how well Darwin’s work was accepted?
      ::如果达尔文知道门德尔的作品,那会如何影响他的进化理论? 你认为这会影响达尔文的作品被接受的程度吗?