大學(xué)生物專業(yè)英語lessonth(存儲版)
【正文】 ptinemal plex 聯(lián)會復(fù)合物 Asexual , 無性生殖的 catastrophic , 災(zāi)難的 Elimination , 除去 , 消除 , 消滅 College of Life Sciences Hubei Normal University 2022/2/10 6 1. The nucleus and chromosomes College of Life Sciences Hubei Normal University 2022/2/10 7 The cell nucleus is the main repository of geic information. 細(xì)胞核是貯藏遺傳信息的主要場所 。 Organisms whose cells contain two sets of parental chromosomes are called diploid。 and G2, a brief period of metabolism and additional growth. 前三個時期包括 G1,正常新陳代謝時期； S期 , 生物分子的合成繼續(xù) ， 同時 ， DNA復(fù)制 ， 組蛋白合成； G2 期， 新陳代謝和進(jìn)一步生長的短暫時期 。 College of Life Sciences Hubei Normal University 2022/2/10 22 Next, during anaphase, the two sister chromatids of each chromosome split, and one from each pair is drawn toward each pole of the cell. 在分裂后期 ， 兩個姊妹染色單體分離 ， 分別被拉向細(xì)胞兩極 。 動粒（ kiochore）：位于著絲粒外側(cè)的蛋白質(zhì)復(fù)合體。 (減數(shù)分裂是性細(xì)胞分裂的特殊形式 。 It is this event that results in the halving of the chromosome number in the four daughter cells that result from meiosis. 由此而導(dǎo)致 4個子細(xì)胞中染色體數(shù)減半 。 College of Life Sciences Hubei Normal University 2022/2/10 46 A major disadvantage of the asexual mode is that a single catastrophic event or disease may destroy an entire population of geically identical anisms. 無性生殖的一個主要的劣勢是 ， 一個簡單災(zāi)難性事件或疾病都可能摧毀遺傳上一致的整個種群 。 Each means of passing on hereditary information has advantages. 每種傳遞遺傳信息的方式各有優(yōu)勢 。 The homologous pairs stay together when they align on the metaphase plate. 同源染色體對一起成線形排列在中期赤道板上 。 (在植物細(xì)胞中 ， 在赤道板形成新的細(xì)胞板 。 College of Life Sciences Hubei Normal University 2022/2/10 25 Mitosis: prophase metaphase anaphase telophase ?chromosome condensation ?mitotic spindle assembly ?nuclear envelope breakdown ?chromosomes align in the central plane ?sister chromatids split and are drawn by the spindle towards the poles Prophase Sister chromatids Prometaphase Metaphase Anaphase Cytokinesis Telophase Interphase Centrosome Microtubule ?spindle microtubules attach to kiochore ?nuclear envelope reforms College of Life Sciences Hubei Normal University 2022/2/10 26 著絲粒（ centromere）：位于染色體縊縮部位，是異染色質(zhì)，是在染色體最后復(fù)制的部位。 (分裂前期 ， 高度濃縮的兩個染色單體通過著絲粒連接在一起形成染色體 ) College of Life Sciences Hubei Normal University 2022/2/10 21 As prophase ends and metaphase begins, the condensed chromosomes bee associated with the spindle. 分裂前期結(jié)束 ， 緊接著是分裂中期 ， 濃縮的染色體與紡錘體相連 。 College of Life Sciences Hubei Normal University 2022/2/10 16 The first three include G1, the period of normal metabolism。s chromosomes in the coiled, condensed state is known as a karyotype. 生物體中的致密的超螺旋狀態(tài)的染色體的表型稱為核型 Karyotype reveal that in most cells all but sex chromosomes a
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