有丝分裂mitosis
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mitosis的意思是有丝分裂。
cytokinesis的意思是胞质分裂，它是指有丝分裂或减数分裂之后发生的细胞质的分裂.在细胞分裂末期时，通常于核分裂之后接着发生的胞质体（cytoplast）的分裂。
这个链接是胞质分裂的解释：http://baike.baidu.com/view/559773.htm
1、从适用范围来区别有丝分裂和减数分裂
有丝分裂适用于真核生物体细胞增殖，减数分裂适用于真核生物有
性生殖细胞的形成。
2、从表格式、坐标式的角度区别有丝分裂和减数分裂
（1）表格式。在有丝分裂和减数分裂过程中，细胞核内DNA含量及染色体数目的变化可用表格表示（见表1、表2）
（2）坐标式。有丝分裂和和减数分裂过程中DNA含量和染色体数目变化也可用坐标曲线表示（图1、图2）
3、从图
解式角度认识有丝分裂和减数分裂，根据同源染色体的行为变化进行“三看”图形（表3）
注：若染色体的着丝点已分开，则只看细胞的一极。
一看细胞中的染色体数目：如果细胞中染色体数为奇数，一定是减数第二次分裂，而且细胞中一定没有同源染色体存在；如果染色体数为偶数，则进行第二看。
二看细胞中有无同源染色体：如果没有同源染色体，一定是减数第二次分裂；如果有同源染色体存在，则进行第三看。
三看细胞中同源染色体的行为：若出现联会、四分体、着丝点位于赤道板两侧，同源染色体分离等现象，一定是减数第一次分裂；若无上述特殊行为，则为有丝分裂。
根据这些，我们可以归纳如下：
4、从细胞分裂结果来认识有丝分裂与减数分裂
（1）看子细胞数目。 1）有丝分裂的结果产生2个子细胞；
2）精原细胞经减数分裂产生4个精细胞； 3）卵原细胞经减数分裂产生1个卵细胞和3个极体。
（2）看子细胞的形态变化 1）有丝分裂产生的子细胞，大小相同； 2）精子形成过程需要经变形阶段；
3）卵细胞的形成不经变形阶段，但型体大。
【有丝分裂】
有丝分裂（mitosis），又称做间接分裂，由W. Fleming于1882年首次发现于动物及E. Strasburger（1880）年发现于植物。特点是有纺锤体染色体出现，子染色体被平均分配到子细胞，这种分裂方式普遍见于高等动植物（动物和高等植物）。是真核细胞分裂产生体细胞的过程。动物细胞（低等植物细胞）和高等植物细胞的有丝分裂是不同的。
【成熟分裂】
成熟分裂即减数分裂，是指生殖细胞在完全受精（核的合体）前成熟过程的一种分裂。其两次分裂分别称为第一次成熟分裂（first maturation division）、第二次成熟分裂（second maturation division）。
减数分裂过程中同源染色体和非姐妹染色单体间发生交换(基因重组)，使配子的遗传多样化，增加了后代对环境的适应性，因此减数分裂不仅是保证生物种类染色体数目稳定的机制，同时也是物种适应环境变化不断进化的机制。减数分裂不仅是保持物种遗传物质稳定传递的手段；在减数分裂过程中，通过同源染色体非姐妹染色单体的交叉互换，非同源染色体的自由组合以及四分体中非姐妹染色体的部分片段的交叉互换，增加了基因变异种类，增强了群体的遗传多样性，为自然选择提供更多原材料。
Dye quality gradual the Ning Suo become thick, at first is a curl for one regiment snarled hemp, subsequently ability peg out each chromosome, and obvious can see each chromosome to dye from 2 list body constitute of, 2 dye list body total use 1 silk point.Pit Ren and pit film gradual become unclear.Spindle silk beginning formation.
Middle:
Pit Ren and pit the film be complete disappear, spindle body obvious it is thus clear that.From the on the side observation of cell, wear of each chromosome silk point all arrange on the spindle body central equator noodles, but it two the arm then at liberty stretch two side of noodles in equator.At this time, the chromosome have the shape of typical model and be suitable for an observation and record number.
Empress period:
The wear of each chromosome silk grain break asunder, each 2 of chromosome dye list body respectively separate but become two independence of chromosome, and at spindle silk of lead bottom to move respectively to two pole.Move to two pole of chromosome number is complete similar, and together front the abruption mother the chromosome number, appearance of the cell complete similar.
Last phase:The chromosome has already moved to two pole, around the chromosome re- appear pit Ren pit film, chromosome again re- become lax thin long, reply is dye quality of appearance.Go to this, a mother is inside cell formation two statures pit.Immediately after in the spindle body of the formation cell of plank district in the equator plank, the cell quality be box off to open, a mother cell division is two complete homology of sub- cell.Subsequently, the sub- cell get into G1 a period again.
The mitotic whole process is a continuous of process, divide the line is front, medium, after, the end be four period is artificial of, just is describe convenience just, in actually the abruption the process in no way obvious of partition.Include a silk abruption to need time, because of species and the external world environment but difference, under the 250 c, broad bean root point the cell need a 2 hr around, but garden pea root point cell need 83 minutes.Under the 30 c, the broad bean root point cell then need 880 minutes.In the abruption the process, front period keep on of period most long, share whole abruption around time of the half be even more.
Events during Mitosis
Interphase: Cells may appear inactive during this stage, but they are quite the opposite. This is the longest period of the complete cell cycle during which DNA replicates, the centrioles divide, and proteins are actively produced. For a complete description of the events during Interphase, read about the Cell Cycle.
Prophase: During this first mitotic stage, the nucleolus fades and chromatin (replicated DNA and associated proteins) condenses into chromosomes. Each replicated chromosome comprises two chromatids, both with the same genetic information. Microtubules of the cytoskeleton, responsible for cell shape, motility and attachment to other cells during interphase, disassemble. And the building blocks of these microtubules are used to grow the mitotic spindle from the region of the centrioles.
Prometaphase: In this stage the nuclear envelope breaks down so there is no longer a recognizable nucleus. Some mitotic spindle fibers elongate from the centrioles and attach to kinetochores, protein bundles at the centromere region on the chromosomes where sister chromatids are joined. Other spindle fibers elongate but instead of attaching to chromosomes, overlap each other at the cell center.
Metaphase: Tension applied by the spindle fibers aligns all chromosomes in one plane at the center of the cell.
Anaphase: Spindle fibers shorten, the kinetochores separate, and the chromatids (daughter chromosomes) are pulled apart and begin moving to the cell poles.
Telophase: The daughter chromosomes arrive at the poles and the spindle fibers that have pulled them apart disappear.
Cytokinesis: The spindle fibers not attached to chromosomes begin breaking down until only that portion of overlap is left. It is in this region that a contractile ring cleaves the cell into two daughter cells. Microtubules then reorganize into a new cytoskeleton for the return to interphase.
网上找到的,具体参考http://www.cellsalive.com/mitosis.htm
Events during Mitosis
Interphase: Cells may appear inactive during this stage, but they are quite the opposite. This is the longest period of the complete cell cycle during which DNA replicates, the centrioles divide, and proteins are actively produced. For a complete description of the events during Interphase, read about the Cell Cycle.
Prophase: During this first mitotic stage, the nucleolus fades and chromatin (replicated DNA and associated proteins) condenses into chromosomes. Each replicated chromosome comprises two chromatids, both with the same genetic information. Microtubules of the cytoskeleton, responsible for cell shape, motility and attachment to other cells during interphase, disassemble. And the building blocks of these microtubules are used to grow the mitotic spindle from the region of the centrioles.
Prometaphase: In this stage the nuclear envelope breaks down so there is no longer a recognizable nucleus. Some mitotic spindle fibers elongate from the centrioles and attach to kinetochores, protein bundles at the centromere region on the chromosomes where sister chromatids are joined. Other spindle fibers elongate but instead of attaching to chromosomes, overlap each other at the cell center.
Metaphase: Tension applied by the spindle fibers aligns all chromosomes in one plane at the center of the cell.
Anaphase: Spindle fibers shorten, the kinetochores separate, and the chromatids (daughter chromosomes) are pulled apart and begin moving to the cell poles.
Telophase: The daughter chromosomes arrive at the poles and the spindle fibers that have pulled them apart disappear.
Cytokinesis: The spindle fibers not attached to chromosomes begin breaking down until only that portion of overlap is left. It is in this region that a contractile ring cleaves the cell into two daughter cells. Microtubules then reorganize into a new cytoskeleton for the return to interphase
我也是在网上查的
What is (and is not) mitosis? Mitosis is nuclear division plus cytokinesis, and produces two identical daughter cells during prophase, prometaphase, metaphase, anaphase, and telophase. Interphase is often included in discussions of mitosis, but interphase is technically not part of mitosis, but rather encompasses stages G1, S, and G2 of the cell cycle.
Interphase & mitosis Interphase
The cell is engaged in metabolic activity and performing its prepare for mitosis (the next four phases that lead up to and include nuclear division). Chromosomes are not clearly discerned in the nucleus, although a dark spot called the nucleolus may be visible. The cell may contain a pair of centrioles (or microtubule organizing centers in plants) both of which are organizational sites for microtubules.
Prophase
Chromatin in the nucleus begins to condense and becomes visible in the light microscope as chromosomes. The nucleolus disappears. Centrioles begin moving to opposite ends of the cell and fibers extend from the centromeres. Some fibers cross the cell to form the mitotic spindle.
Prometaphase
The nuclear membrane dissolves, marking the beginning of prometaphase. Proteins attach to the centromeres creating the kinetochores. Microtubules attach at the kinetochores and the chromosomes begin moving.
Metaphase
Spindle fibers align the chromosomes along the middle of the cell nucleus. This line is referred to as the metaphase plate. This organization helps to ensure that in the next phase, when the chromosomes are separated, each new nucleus will receive one copy of each chromosome.
Anaphase
The paired chromosomes separate at the kinetochores and move to opposite sides of the cell. Motion results from a combination of kinetochore movement along the spindle microtubules and through the physical interaction of polar microtubules.
Telophase
Chromatids arrive at opposite poles of cell, and new membranes form around the daughter nuclei. The chromosomes disperse and are no longer visible under the light microscope. The spindle fibers disperse, and cytokinesis or the partitioning of the cell may also begin during this stage.
Cytokinesis
In animal cells, cytokinesis results when a fiber ring composed of a protein called actin around the center of the cell contracts pinching the cell into two daughter cells, each with one nucleus. In plant cells, the rigid wall requires that a cell plate be synthesized between the two daughter cells
Events during Mitosis
Interphase: Cells may appear inactive during this stage, but they are quite the opposite. This is the longest period of the complete cell cycle during which DNA replicates, the centrioles divide, and proteins are actively produced. For a complete description of the events during Interphase, read about the Cell Cycle.
Prophase: During this first mitotic stage, the nucleolus fades and chromatin (replicated DNA and associated proteins) condenses into chromosomes. Each replicated chromosome comprises two chromatids, both with the same genetic information. Microtubules of the cytoskeleton, responsible for cell shape, motility and attachment to other cells during interphase, disassemble. And the building blocks of these microtubules are used to grow the mitotic spindle from the region of the centrioles.
Prometaphase: In this stage the nuclear envelope breaks down so there is no longer a recognizable nucleus. Some mitotic spindle fibers elongate from the centrioles and attach to kinetochores, protein bundles at the centromere region on the chromosomes where sister chromatids are joined. Other spindle fibers elongate but instead of attaching to chromosomes, overlap each other at the cell center.
Metaphase: Tension applied by the spindle fibers aligns all chromosomes in one plane at the center of the cell.
Anaphase: Spindle fibers shorten, the kinetochores separate, and the chromatids (daughter chromosomes) are pulled apart and begin moving to the cell poles.
Telophase: The daughter chromosomes arrive at the poles and the spindle fibers that have pulled them apart disappear.
Cytokinesis: The spindle fibers not attached to chromosomes begin breaking down until only that portion of overlap is left. It is in this region that a contractile ring cleaves the cell into two daughter cells. Microtubules then reorganize into a new cytoskeleton for the return to interphase
丛谢辅舒： 1、有丝分裂(Mitosis)有丝分裂,又称为间接分裂,由W. Fleming (1882)年首次发现于动物及E. Strasburger(1880)年发现于植物.2、特点是有纺锤体染色体出现,子染色体被平均分配到子细胞,这种分裂方式普遍见于高等动植物(动物和低等植物).3、是真核细胞分裂产生体细胞的过程.4、分为分裂间期和分裂期.
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