大學(xué)生物專業(yè)英語(yǔ)lessonth(編輯修改稿)
2025-02-09 19:15 本頁(yè)面
【文章內(nèi)容簡(jiǎn)介】 a plane (called the metaphase plate) at a right angle to the spindle fiber. 最后染色體在紡錘絲的牽引下以 正確的角度 排列在赤道板上 。 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(gè)姊妹染色單體分離 ， 分別被拉向細(xì)胞兩極 。 During telophase nuclear envelope begin to form around each set of chromosomes, and division of the cytoplasm takes place. 在分裂末期 ， 在每套染色體周圍形成核膜 ， 細(xì)胞質(zhì)分裂發(fā)生 。 College of Life Sciences Hubei Normal University 2022/2/10 23 As mitosis proceeds, the spindle microtubules play a crucial role in ensuring that both paired and separated chromatids move in the right directions at the proper times. 在有絲分裂過程中 ， 紡錘體微管在確保染色單體配對(duì)和在適當(dāng)時(shí)間以正確方向進(jìn)行分離中發(fā)揮了關(guān)鍵性的作用。 Each half of the spindle forms as microtubules extend from each pole of a dividing cell to the region of the metaphase plate. 微管從正在分裂的細(xì)胞兩極向赤道板延伸 ， 就形成了紡錘體的一半 。 College of Life Sciences Hubei Normal University 2022/2/10 24 During prophase, other microtubules, the centromeric fiber, extend outward from the spindle poles to structures on the chromosomes called kiochores. 在分裂前期 ， 其它微管 ， 著絲粒纖維從紡錘體的兩極延伸到染色體的動(dòng)粒區(qū)域 。 During anaphase the fibers begin to shorten, and the chromatids begin to move apart. 在分裂后期，纖維開始變短，染色單體分離。 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。著絲粒在染色體上的位置是確定的。 動(dòng)粒（ kiochore）：位于著絲粒外側(cè)的蛋白質(zhì)復(fù)合體。 College of Life Sciences Hubei Normal University 2022/2/10 27 College of Life Sciences Hubei Normal University 2022/2/10 28 The spindle forms differently in plant and animal cells. 植物和動(dòng)物細(xì)胞中的紡錘體的形成是不同的。 In animal it is associated with centriole, while in plant and fungal cells spindle formation is associated with regions called microtubule anizing centers. 在動(dòng)物中，紡錘體的形成與中心粒相關(guān)，而在植物和真菌細(xì)胞中，紡錘體的形成與微管組織中心相關(guān)。 College of Life Sciences Hubei Normal University 2022/2/10 29 4. Cytokinesis: Partitioning the cytoplasm 胞質(zhì)分裂：細(xì)胞質(zhì)分離 College of Life Sciences Hubei Normal University 2022/2/10 30 The d
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