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英语翻译原文:The Product of Meiosis IMeiosis I results in two inde

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英语翻译
原文:
The Product of Meiosis I
Meiosis I results in two independent cells.One cell contains the maternal homologous pair,with a small segment of the paternal chromosome from crossover.The other cell contains the paternal homologous pair,likewise with a small segment of the maternal chromosome.Despite the small region of crossover in the chromosomes of each cell,the maternal sister chromatids are still quite similar,as are the paternal sister chromatids.Both cells formed by meiosis I contain a haploid amount of DNA.
The cells produced in meiosis I are different from those produced in mitosis because both haploid members of the meiotic pair derive from random assortments of either the maternal or paternal chromosomes from each homologous pair (with the exception of the small crossover sections).In mitosis,the cellular division separates sister chromatids and results in diploid cells containing one maternal and one paternal copy in each diploid pair.
Meiosis II
The cells produced by meiosis I quickly enter meiosis II.These cells do not undergo DNA replication before entering meiosis II.The two cells that move from meiosis I into meiosis II are haploid—each have 23 replicated chromosomes,rather than the 46 that exist in cells entering both mitosis and meiosis I.
Meiotic division II occurs through the familiar phases from meiosis I and mitosis.To distinguish the phases,they are called prophase II,metaphase II,anaphase II,and telophase II.One important difference between the events of meiosis I and II is that no further genetic reassortment takes place during prophase II.As a result,prophase II is much shorter than prophase I.In fact,all of the phases of meiosis II proceed rapidly.
During meiosis II,chromosomes align at the center of the cell in metaphase II exactly the way they do in mitotic metaphase.In anaphase II,the sister chromatids separate,once again in the same fashion as occurs in mitotic anaphase.The only difference is that since there was no second round of DNA replication; only one set of chromosomes exists.When the two cells split at the end of meioisis II,the result is four haploid cells.
Of the four haploid cells,one cell is composed completely of a maternal homologue,another of a maternal homologue with a small segment of paternal DNA from crossover in meiosis I,another complete paternal homologue,and a final paternal homologue with a small segment of maternal DNA from crossover in meiosis I.These four haploid cells are the gametes,the sperm or egg cells,that fuse together in sexual reproduction to create new individuals.
哈哈 我是学生物的啊 有些材料 我可以翻译一下 以后要是有需要翻译的话 我可以帮帮忙
我看了一下你这个文章,它的过程和我所学的过程不太一样啊……我不理解其母系和父系的含义.我试着翻译一下吧.
减数第一次分裂的结果
减数第一次分裂产生了两个独立的细胞.一个细胞含有同源染色体中的母方那部分和一小部分由于交叉互换换来的父方的片段,另一个含有同源染色体中的父方那部分以及交叉互换来的母方的片段.尽管每个细胞中的染色体上会有交叉互换,每条染色体的两个姐妹染色单体仍然是很相似的.每个细胞内含有单倍体的DNA的量.
减数第一次分裂所产生的子代细胞和有丝分裂产生的子细胞是不同的.因为在减数第一次分裂中,每对同源染色体中的父方的染色体和母方的染色体在分离的同时,非同源染色体之间会自由组合(除了交叉互换的部分)来形成两个单倍体的细胞.在有丝分裂过程中,姐妹染色单体的分开导致了每个子细胞中仍然有二倍体的同源染色体中的父方和母方的染色体.每个子细胞仍是二倍体.
减数第二次分裂
减数第一次分裂的细胞会迅速进行减数第二次分裂.在减数第二次分裂之前不进行DNA的复制.从减一到减二的细胞是单倍体——每个都含有23条复制的染色体,而不是进行减一和有丝分裂的时候含有46条.减数第二次分裂会进行和减一和有丝分裂相似的阶段.为了区分这些阶段,在减二中分别叫做减二前期、减二中期、减二后期和减二末期.减二和减一在发生上的一个重要的差别在于,减二中不再进行遗传物质的重新分配和组合.结果,减二的每个时期进行的都会比减一的时间短.实际上,减二的每个阶段都进行的很快.
就像在有丝分裂中期一样,减二中期的每条染色体都排布在细胞的中央.在减二后期,也是和有丝分裂一样,是姐妹染色单体分离.唯一的区别是,因为没有进行DNA的复制,每个细胞中只有一半的染色体.在进行减数第二次分裂的两个细胞分裂结束时,产生的是四个单倍体细胞.
这四个单倍体的细胞中,一个完全含有母方的染色体,一个含大部分的母方染色体以及由于减一进行交叉互换得来的父方的部分,还有两个细胞,分别含有全部的父方的染色体和大部分父方的染色体以及减一交叉互换得来的母方的部分.这四个单倍体的细胞是配子,叫做精细胞或卵细胞.他们在有性生殖过程中会随机结合形成受精卵后发育成个体.
对于这篇文章 ,我是按照他给的内容译的.但是,在减一时,非同源染色体中的父方的染色体和母方的染色体会自由组合.产生的子细胞全包括母方或父方的染色体的概率很小很小.其次,减一产生的子代细胞,染色体是单倍体的量,但是DNA不是.第三,减二是产生四个子细胞,但是,精原细胞产生四个精细胞,但是卵原细胞只产生一个卵细胞,而不是四个卵细胞.