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  • 继承继承继承 概率 - 高级

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    What are the odds of landing on 23 again?
    ::23号着陆的几率有多大?

    Not as high as inheriting an from a parent. Probability plays a big role in determining the chance of inheriting an allele from a parent. It is similar to tossing a coin. What's the chance of the coin landing on heads? What's the chance of inheriting the paternal allele? Or the maternal allele?
    ::概率在决定从父母继承异性的可能性方面起着很大的作用。 它与抛硬币相似。 硬币落头的可能性有多大? 继承父性异性的可能性有多大? 还是母性异性?

    Probability and Genetics
    ::概率和遗传学

    A Mendelian trait is a trait that is controlled by a single gene that has two alleles. One of these alleles is dominant and the other is recessive . Many inheritable conditions in humans are passed to offspring in a simple Mendelian fashion. Medical professionals use Mendel’s laws to predict and understand the inheritance of certain traits in their patients. Also, farmers, breeders, and horticulturists who breed organisms can predict outcomes of crosses by understanding and probability.
    ::门德尔形的特性是由单一基因控制的特性,该基因有两个异变。其中一种异变占主导地位,而另一种则处于休眠状态。 人类的许多可继承条件以简单的门德尔式方式传给后代。 医学专业人员利用门德尔法来预测和理解病人某些特征的遗传。 此外,培育生物的农民、育种者和园艺学家可以通过理解和概率来预测交叉结果。

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    Tossing a Coin. Competitions often begin with the toss of a coin. Why is this a fair way to decide who goes first? If you choose heads, what is the chance that the toss will go your way? Is this similar to the probability of inheriting a particular allele?

    The rules of probability that apply to tossing a coin or throwing a die also apply to the laws of segregation and independent assortment . Probability is the likelihood that a certain event will occur. It is expressed by comparing the number of events that occur to the total number of possible events. The equation is written as:
    ::抛掷硬币或抛掷死亡的概率规则也适用于隔离法和独立分类法。 概率是指发生某一事件的可能性。 发生事件的次数与可能发生的事件的总数比较, 表示出这种可能性。 方程式的写法是:

    Probability = (number of times an event is expected to occur)/(total number of times an event could happen)
    ::概率=(事件预期会发生的次数)/(事件可能发生的次数总数)

    For example, in Mendel’s F 2 hybrid generation, the dominant trait of purple flower color appeared 705 times, and the recessive trait appeared 224 times. The dominant allele appeared 705 times out of a possible 929 times (705+224=929).
    ::例如,在门德尔的F2混合代中,紫花色的主要特征出现705次,消退性特征出现224次。 在929次(705+224=929 ) 中,占优势的异性出现了705次(705+224=929 ) 。

    Probability = (705/929)
    ::概率=(705/929)

    (705/929)= 0.76

    Probability is normally expressed in a range between 0 and 1, but it can also be expressed as a percentage, fraction, or ratio. Expressed as a percentage, the probability that a plant of the F 2 generation will have purple flowers is 76%. Expressed as a fraction it is about ¾,and as a ratio it is roughly 3:1. The probability of the expression of the dominant allele for other characteristics can also be calculated the same way. In fact, found that all the other dominant “factors” had approximately a ¾ probability of being expressed in the F 2 hybrid generation. Review  Table for the results for the other six characteristics.
    ::概率通常在0到1之间,但也可以以百分比、分数或比率表示。以百分比表示,F2代植物有紫花的概率为76%。以小数表示,大约为3⁄4,比例约为3:1。其他特性占支配地位的异端表示的概率也可以以同样方式计算。事实上,所有其他占支配地位的“因素”在F2混合型植物中有大约3⁄4的表示概率。其他6种特性的结果审查表。

    Results of F1 Generation Crosses for Seven Characteristics in
    Characteristic Dominant Trait Recessive Trait F2 Generation (Dominant:Recessive) Ratio
    Flower Color purple white 705:224 3.15:1
    Flower Position on axial terminal 651:207 3.14:1
    Stem Length tall short 787:277 2.84:1
    Pod Shape inflated constricted 882:299 2.95:1
    Pod Color green yellow 428:152 2.82:1
    Seed Shape round wrinkled or angular 5474:1850 2.96:1
    Seed Color yellow green 6022:2001 3.01:1

    The probability the recessive trait will appear in the F 2 hybrid generation is calculated in the same way.
    ::F2混合代的消融性能出现的可能性也是以同样的方式计算的。

    Probability = (224/929)
    ::概率=(224/929)

    (224/929) = 0.24

    The probability of the recessive trait appearing in the F 2 generation is 24% or about ¼.
    ::F2代的消亡性能概率为24%或大约四分之一左右。

    Results predicted by probability are most accurate when many trials are done. The best way to illustrate this idea is to toss a coin. Because a coin has two sides, every time you toss it the chance of tossing heads or tossing tails is 50%. The outcome of each separate toss is unaffected by any previous or future result. For example, imagine you tossed seven heads in a row. You would think that the next toss is more likely to be a tail, but the possibility of tossing another head is still 50%. If you tossed the coin a total of ten times, a total of seven heads and three tails, you would calculate the probability of tossing heads is 70%. The fact that you carried out only a small number of trials has affected your results. If Mendel had grown only 10 plants, he would have gotten different probabilities for the appearance of dominant and recessive traits. However, Mendel carried out many thousands of trials. He was therefore sure that his results were due to probability, and not to chance.
    ::进行多次试验时, 概率预测的结果是最准确的。 最能说明这个想法的方法是抛硬币。 因为硬币有两面, 每次抛掷抛头或抛尾的可能性是50%。 每一次抛头或抛尾的概率是50% 。 每一次抛头或抛尾的结果都不受任何先前或未来结果的影响 。 比如, 想象一下, 你一连抛七头。 您会认为, 下一头更可能是尾巴, 但抛掷另一头的可能性仍然是50 % 。 如果您抛掷硬币总共十次, 共七头和三尾, 你就会计算抛头的概率是70% 。 您只进行了少量的试验, 这一事实影响了你的结果 。 如果Mendel只种植了10个植物, 他就会得到不同的概率 。 但是, Mendel 会进行成千上万的试验。 因此, 他确信结果是概率的, 而不是概率的 。

    Probability and the Law of Segregation
    ::概率和隔离法

    Each coin toss is a separate event. Likewise, gamete formation is a separate event. The probability that a Pp heterozygote produces gametes with a P allele or a p allele is 50% for each gamete . In a involving two such plants (as in the F 1 generation self- pollination experiment), each pollen cell and each egg cell have a 50% chance of having the P or p allele.
    ::每个抛硬币是一个单独的事件。 同样, 调子形成是一个单独的事件。 Pp heterozygote 产生配有 Palle 或 pelete 的调子的概率是每个调子的 50% 。 在涉及两个这样的植物(如F1 一代自我污染实验 ) 的情况下, 每个花粉细胞和每个蛋细胞拥有 P 或 pelete 50% 的机会 。

    Using Probability to Determine Alleles in Gametes
    ::使用概率确定 Gamete 中的alleles 的概率

    In Mendel's monohybrid cross, two heterozygous plants are crossed. Both plants produce gametes, all of which contain either a P or p allele for flower color. The likelihood that any particular gamete contains the allele for a white flower can be calculated. Because a gamete can only carry one out of two alleles, there are only two possible outcomes for a gamete. The probability that a gamete will carry the allele for white flower color is ½, 0.5, or 50%. The probability that a gamete will carry the allele for purple flower color is also ½.
    ::在门德尔的单合金十字架上, 横跨了两个异体形的植物。 两种植物都产生调子, 都含有花色的P 或 折价。 任何特定的调子含有白花的折价。 任何特定的调子都包含白花的折价。 因为一个调子只能执行两个相位数中的一个, 一个调子只能产生两个结果。 一个调子会携带白花色的折价符的概率是 1⁄2, 0. 5 或 50 。 一个调子会携带紫花色的折价符的概率也是 1⁄2 。

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    Formation of gametes by meiosis. Paired alleles always separate and go to different gametes during meiosis.

    Using Probability in a Heterozygous Cross
    ::在赫特罗兹古斯十字架上使用概率

    We can calculate the probability of any one of the offspring being heterozygous ( Pp ) or homozygous ( PP or pp ) for flower color. The probability of a plant inheriting the P or p allele from a heterozygous parent is ½. Multiply the probabilities of inheriting both alleles to find the probability that any one plant will be a pp homozygote .
    ::我们可以计算出任何一种后代因花色而成为异体兹古斯(Pp)或同体古斯(PP或pp)的概率。植物从异体兹古斯父母继承P或异体灵球的概率是1⁄2。 乘以继承这两种异体的概率,可以发现任何一种植物都具有同种植物的概率。

    ½ × ½ = ¼ or 0.25
    ::1⁄2=1⁄2=1⁄4或0.25

    Only 25 %, or one outcome out of four, will result in a plant homozygous for white flower color ( pp ). The possibility that any one plant will be a PP homozygote is also 1/4. The heterozygous allele combination can happen twice ( Pp or pP ), so the two probabilities are added together ¼ + ¼ = 2/4, or ½. The probability that an offspring plant will be Pp heterozygous is ½.
    ::只有25%,即四分之一的结果,将导致白花色(pp)的植物同质同质。 任何一种植物都有可能是PP同质果酸( Pp 或 PP ) 。 异性合金组合可以发生两次( Pp 或 PP ) , 所以两种概率相加的概率是 1⁄4 + 1⁄4 = 2/4 或 1⁄2 。 后代植物可能是 Pp 异性合金的概率是 1⁄2 。

    Summary
    ::摘要

    • Probability is the likelihood that a certain event will occur. It is expressed by comparing the number of events that actually occur to the total number of possible events.
      ::概率是某一事件发生的可能性,其表现是将实际发生的事件数目与可能发生的事件的总数进行比较。
    • Probability can be expressed as a fraction, decimal, or ratio.
      ::概率可以以小数、小数或比率表示。

    Review
    ::回顾

    1. Define probability. Apply the term to a coin toss.
      ::定义概率。将术语应用到抛掷硬币 。
    2. How is gamete formation like tossing a coin?
      ::游戏的形成如何 喜欢抛硬币?
    3. What does the probability equation help to determine?
      ::概率方程式能帮助确定什么?
    4. How can probability be expressed?
      ::如何表达概率?