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鈺翔 發問時間: 社會與文化語言 · 8 年前


1.How many Barr bodies can be identified in the cell of Klinefelter syndrome males?




(d)02.In fruit fly,monosomy(7,X)is a





(e)metafemale3.Determination of the coiling

in the snail is

(a)infectious heredity

(b)organelle heredity

(c)matemale effect

(d)chromosomal heredity4.Which gene may have multiple duplications in the cell?




(d)histone5.In a lab,purified plasmid can be introduccd into E.coli by heat-shock method,this proecess is called




(d)infection6.Glucose-6-phosphate dehydrogenase deficiency(G6PD)is inherited as an X-linked recessive gene in humans.A woman whose father suffered from G6PD marries a normal man.

(A小題)What proportion of their sons is expected to be G6PD?






(B小題)If the husband was not normal but was G6PD deficient,what proportion of their sons is expected to be G6PD?






1 個解答

  • 8 年前

    1. (a)

    Klinefelter males have the sex chromosome of XXY, which means that they have an extra X chromosome. The reason Barr bodies appear is because one of the X chromosomes is "shut down" and becomes inactive. In any case, the number of Barr bodies will always be the number of X chromosomes minus 1.

    2. (b)

    Monosomy is the case where there is only one chromosome as opposed to two. The answer to this question can be inferred without exact knowledge of fruit fly genetics, since an individual with Turner's syndrome (monosomy for X chromosome in humans) is female.

    3. (d)

    The coiling of snail shells is determined by one gene, which implies that it is the result of chromosomal inheritance. Process of elimination may also help here, as there is no such thing as the matemale effect, organelle inheritance is the passing on of genetic material of organelles (mitochondria and chloroplasts), and infectious inheritance applies to viruses.

    4. (b)

    rDNA and cDNA are both obviously wrong for this question, since it's asking for a gene, and those are both genetic material (rDNA being recombinant DNA, or DNA that has been spliced into a plasmid, and cDNA being a reverse transcript of mRNA). Histones are single-subunit proteins, and thus would be less likely to have multiple genes that code for it. Hemoglobin is the best choice.

    5. (a)

    Transduction involves a viral vector for the transfer of genetic material, conjugation requires contact between two bacterial cells. The only method that is uptake directly from the environment is transformation.

    6A. (b)

    6B. (b)

    Draw a punit square. Since the question only asks about the male offspring, the genetic traits of the father is not important in this case, as it is an X-linked trait. The mother is a carrier - meaning that she has one recessive and one dominant chromosome (heterozygous) - and so in either case the sons have a 50% chance of having the deficiency.

    參考資料: my son
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