summary of mitosis
@ Mitosis begins Cell moves from interphase into mitosis-----DNA and chromosome (have been replicated and ready to separate) 细胞相间移动，DNA和chromosome已经复制，准备分离 Biologists often refer to the process in separate subphases because of significant events that occur. 一般当成单独的子阶段，因为重要
@The phases of mitosis
1. Prophase (before phase)
Chromosomes become visible as thread-like form when using light microscope.
Each chromosome is duplicated and consists of two sister chromatids, join together by a centromere. 每个chromosome由2个sister chromatids组成，用centromere连接
Centromere ----a constricted area of DNA where the two parts of the replicated chromosome are most closely attached. 受限制部位 Every replicated chromosome has a centromere in the same position. 被复制的chromosomes Meanwhile in the cytoplasm, microtubules are being assembled. 同时在细胞质，聚集 Microtubules----- are protein units that are assembled in the cell. (assemble 聚集)
When nuclear membrane is intact, microtubules cannot reach the chromosomes. membrane完整
When nuclear membrane starts to break down, microtubules start to interact with the chromosomes. 与chromosomes相互作用 Microtubules from either side of the cell attach to either face of the chromosome at the centromere and start pulling. This two-way pulling, moves chromosomes into the middle part of the cell. (attach 依附)
2. Metaphase (middle phase)
The pulling and pushing of chromosomes ceases temporarily when the chromosomes are aligned in the middle part or equator of the cell. (ceases temporarily:暂时停止, aligned:对齐) When all the chromosomes are aligned on this imaginary line known as a metaphase plate, the cell said to be in metaphase.
3. Anaphase (throughout phase)
The sister chromatids of each chromosome separate from each other and move to opposite sides of the cells. This occurs because the microtubules shorten, by a process of disconnecting and connecting to the centromeres of the chromosomes. (在连接或断开的过程中microtubules shorten)
Once a chromatid is
@The phases of mitosis
1. Prophase (before phase)
Chromosomes become visible as thread-like form when using light microscope.
Each chromosome is duplicated and consists of two sister chromatids, join together by a centromere. 每个chromosome由2个sister chromatids组成，用centromere连接
Centromere ----a constricted area of DNA where the two parts of the replicated chromosome are most closely attached. 受限制部位 Every replicated chromosome has a centromere in the same position. 被复制的chromosomes Meanwhile in the cytoplasm, microtubules are being assembled. 同时在细胞质，聚集 Microtubules----- are protein units that are assembled in the cell. (assemble 聚集)
When nuclear membrane is intact, microtubules cannot reach the chromosomes. membrane完整
When nuclear membrane starts to break down, microtubules start to interact with the chromosomes. 与chromosomes相互作用 Microtubules from either side of the cell attach to either face of the chromosome at the centromere and start pulling. This two-way pulling, moves chromosomes into the middle part of the cell. (attach 依附)
2. Metaphase (middle phase)
The pulling and pushing of chromosomes ceases temporarily when the chromosomes are aligned in the middle part or equator of the cell. (ceases temporarily:暂时停止, aligned:对齐) When all the chromosomes are aligned on this imaginary line known as a metaphase plate, the cell said to be in metaphase.
3. Anaphase (throughout phase)
The sister chromatids of each chromosome separate from each other and move to opposite sides of the cells. This occurs because the microtubules shorten, by a process of disconnecting and connecting to the centromeres of the chromosomes. (在连接或断开的过程中microtubules shorten)
Once a chromatid is