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转基因作物的安全性问题在20世纪末引起全球的争论,一些人反应对转基因植物和转基因技术,本文概述了转基因植物产生的必然性,应用现状,发展趋势,引起争论的主要原因以及必须建立的安全保障,阐明对转基因作物和技术应采取的科学态度。 相似文献
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生物学最基本问题的探索 总被引:1,自引:1,他引:0
科学和哲学既相互区别,又相互联系,两者之间是特殊性与普遍性的关系。普遍性寓于特殊性之中,掌握普遍性有助于更加客观、全面地认识特殊性。这就是哲学对科学的指导作用或思想启示。在生物学中一些重大的理论问题,既是科学问题,又是哲学问题。正像当年爱因斯坦(A.Einstein)和玻尔(N.Bohr)关于量子描述的完备性与量子现象的整体性问题的历史性争论,既是物理学的争论,又是哲学的争论,它涉及了量子力学的方法论原理及其哲学诠释。生物学研究的一个总题目、总概念是关于生命的本质与起源,它涉及生物学最基本的问题:生命是什么?生命是从哪里… 相似文献
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转基因作物和转基因技术的发展与未来 总被引:8,自引:0,他引:8
转基因作物的安全性问题在20世纪末引起全球性的争论,一些人反对转基因植物和转基因技术.本文概述了转基因植物产生的必然性、应用现状、发展趋势、引起争论的主要原因以及必须建立的安全性保障,阐明对转基因作物和技术应采取的科学态度. 相似文献
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综述了近40年生物制品中残存DNA的争论,关于这个问题的研究进展现行标准的制订及检测方法的可靠性,以及WHO专家委员会的意见及这个问题的发展趋势 相似文献
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关于鸟类的进化问题,曾引起一场旷日持久的争论。两位伟大的动物学家赫胥黎和贝尔也曾参加这一争论,争论的焦点是,大型非飞翔的鸵鸟、鸸鹋以及平胸总目中其它有亲缘关系的鸟类,在古鸟类中是否代表了一个古老的类型,或者它们是否由飞鸟类进化而来,而后才转化为不能飞行的鸟类。贝尔等人赞成后一种见解。这一理论自1956年贝尔的著名文章发表后,已受到了许多批评,但仍有许多支持者。现在,加 相似文献
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此文是对本刊 2 0 0 0年第 2期“植物向地性的一种新解释”一文的争论和补充 ,这是很好的事 ,一方面说明读者关心我们的刊物 ,一方面也可使问题越争论越深入 相似文献
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最近,美国人类学家在人类起源问题上展开争论。这场争论是由一块1979年在利比亚沙哈比发掘出的一根长约75.5毫米的骨头引起的。最初给这块骨头分类的美国纽约大学诺埃尔·博厄斯博士认为,它极象人猿超科左侧的锁骨。 相似文献
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通过对6种藓类植物,即褶叶青藓(Brachythecium salebrosum(Web.et Mohr.)B.S.G.)、湿地匐灯藓(Plagiomnium acutum(Lindb.)Kop.)、侧枝匐灯藓(Plagiomnium maximoviczii(Lindb.)Kop.)、大凤尾藓(Fissidensnobilis Griff.)、大羽藓(Thuidium cymbifolium(Doz.et Molk.)B.S.G.)和大灰藓(Hypnum plumaeforme Wils.)嫩茎和老茎的石蜡切片和显微观察发现,同一藓类植株的嫩茎和老茎,茎结构稳定,不同种藓类植物茎横切面具有不同特征.植物体茎横切面形状、表层细胞的层数、细胞大小和细胞壁厚薄、皮层细胞大小和形状、中轴的有无以及比例等特征可以作为藓类植物的分科分类依据之一. 相似文献
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Seed germination of an aurea mutant of tomato ( Lycopersicon esculentum Mill.) is promoted by continuous irradiation with red, far-red or long-wavelength far-red (758 nm) light as well as by cyclic irradiations (5 min red or 5 min far-red/25 min darkness). Far-red light applied immediately after each red does not change the germination behaviour. Seed germination of the isogenic wild-type, cv. UC-105, is promoted by continuous and cyclic red light while it is inhibited by continuous and cyclic far-red light and by continious 758 nm irradiation. Far-red irradiation reverses almost completely the promoting effect of red light. The promoting effect (in the aurea mutant) and the inhibitory effect (in the wild-type) of continuous far-red light do not show photon fluence rate dependency above 20 nmol m−2 s−1 . It is concluded that phytochrome controls tomato seed germination throgh low energy responses in both the wild type and the au mutant. The promoting effect of continuous and cyclic far-red light in the au mutant can be attributed to a greater sensitivity to Pfr . 相似文献
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真菌类遗传学分析的知识结构教学 总被引:5,自引:2,他引:3
本文以认知结构理论为指导,讨论了真菌类遗传分析与高等动植物遗传分析的内在联系,认为利用这种内在联系进行教学可收到好的效果并说明了作者的具体教学过程。
Abstract:In the paper, the relationship between genetic analysis of Fungi and genetic analysis of high animal and plant was discussed.A good results were obtained when we adopted this method in the teaching. 相似文献
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The levels of endogenous phytohormones and respiratory rate in nine sorts of flowers such as Cymbidium faberi Rolfe, Nopalxochia ackermannii Kunth and others were investigated both at full bloom and senescence and meanwhile the effect of exogenous phytohormones on prolonging the blossoms and promoting ethylene production were tested. There is a high content of endogenous ethylene in all the long-lived flowere, about 3–16 folds higer than the short-lived ones. There is a high level of ABA at full blooming flowers of short-lived flowers, in which there is no or only some cytokinins in it, but the ratio of CTK (6BA+zeatin)/ABA is smaller(l.7). The endogenous ABA reached a much higher level at senescence in all nine sorts of flowers, so it is reasonable to consider that it is ABA which plays an important role of regulation in controlling flower's senescence. There is a much higher level of GA3 and zeatin in the long-lived flowers which is not demonstrated in the shortlived ones. The respiratory rate is one of the factors controtling the longevity of flowers, but it does not play a decided role. Application of 6BA and zeatin prolongs distinctly orchid’s longevity, however exogenous IAA through the promotive action on ethylene production, evidently extends the longevity of the flowers of the Nopalxochia ackermannii Kunth. 相似文献
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龙胆科药用植物化学成分的研究现状 总被引:16,自引:0,他引:16
龙胆科植物在我国的分布范围很广,且多数为药用植物,其多数种属的药用植物,至今其化学成分尚未被系统研究。综述了目前龙胆科药用植物的化学成分的研究现状及一般提取方法,对近年来发现的环烯醚萜及裂环烯醚萜类化合物进行了总结,为本科药用植物的更深入研究提供了参考。 相似文献
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M. V. Kozlov V. V. Urnysheva L. N. Shishkina 《Journal of Evolutionary Biochemistry and Physiology》2008,44(4):470-475
A complex analysis of seasonal fluctuations of the mean group parameters of the system of regulation of lipid peroxidation has been performed in liver of Balb/c mice. Association of lipid characteristics and morphophysiological parameters is studied in the Balb/c mouse liver. An inter-connection is revealed between the liver index and the amount of lysoforms of phospholipids, the scale and character of the interconnection differing essentially depending on proportion of phos-phatidylcholine in mouse liver phospholipids. 相似文献
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Time of detection of recessive genes: effects of system of mating and number of examined individuals
E. Santiago 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1989,78(6):867-872
Summary Anthers were cultured from two sets of seven lines of hexaploid wheat (Triticum aestivum L.) with different cytoplasms, the euplasmic nucleus donors, Siete Cerros 66 and Penjamo 62, as well as their six alloplasmic lines derived from wild relative species of the genera Triticum and Aegilops. Significant cytoplasmic and nuclear effects but no cytoplasmic-nuclear interaction were found for embryogenic anther response, with the best performance of Penjamo 62 in Ae. kotschyi cytoplasm. Plant regeneration was not affected significantly by the cytoplasmic background of the lines cultured. The possible genetic implications of the observed cytoplasmic and nuclear influences on the in vitro haploid induction of wheat are discussed. 相似文献
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