What is Mitosis & Meiosis? | Complete | Animated Explanation · FreeMedEducation
动画讲解有丝分裂和减数分裂，适合练习生物术语和细胞分裂过程理解。
What is Mitosis and Meiosis?
什么是有丝分裂（Mitosis）和减数分裂（Meiosis）？
MITOSIS - When The Cell Splits Apart What is mitosis?
有丝分裂（Mitosis）：当细胞分裂时…… 什么是有丝分裂？
Eventually, cells need to duplicate.
最终，细胞需要进行复制。
There are two main methods of replication: mitosis and meiosis.
复制主要有两种方式：有丝分裂（mitosis）和减数分裂（meiosis）。
This tutorial will talk about mitosis.
本教程将介绍有丝分裂（mitosis）的相关内容。
The big idea to remember is that mitosis is the simple duplication of a cell and all its parts.
需要记住的核心概念是：有丝分裂只是细胞及其所有组成部分的简单复制过程。
It duplicates its DNA and that the two new cells, daughter cells, have the same pieces and genetic code.
它会复制自身的DNA，从而产生两个新的细胞（即子细胞），这两个子细胞拥有完全相同的遗传物质和基因编码。
Two identical copies come from one original.
两个完全相同的复制品都来源于同一个原始版本。
Beyond the idea that two identical cells are created, there are certain steps in the process.
除了会产生两个完全相同的细胞这一结果之外，这一过程中还包含一些特定的步骤。
Before a cell divides, it is in resting phase.
在细胞分裂之前，它处于静止期（即细胞不进行任何分裂活动的阶段）。
The cell in resting phase is not actually resting, since it has to maintain its reservoir before it undergoes division.
处于静止期的细胞实际上并非处于真正的“静止”状态，因为它在分裂之前必须先维持自身的物质储备（即各种生物分子的含量）。
This phase is called Interphase.
这个阶段被称为“间期”（Interphase）。
It prepares the cell for division i.e.
它为细胞的分裂做好准备。
protein synthesis, DNA duplication and enzymes.
蛋白质合成、DNA复制以及酶的生成。
After this phase comes Mitosis, which is further divided into Karyokinesis (division of nucleus) and Cytokinesis (division of cytoplasm).
在这一阶段之后，是细胞分裂（Mitosis）过程，该过程进一步分为核分裂（Karyokinesis，即细胞核的分裂）和胞质分裂（Cytokinesis，即细胞质的分裂）。
Karyokinesis involves the four basic steps of mitosis that are PROPHASE - METAPHASE - ANAPHASE - TELOPHASE.
有丝分裂的过程包括四个基本阶段：前期（PROPHASE）、中期（METAPHASE）、后期（ANAPHASE）和末期（TELOPHASE）。
Here we start with PROPHASE.
我们首先从“前相”（PROPHASE）开始讲解。
The chromosomes start coiling and become condensed.
染色体开始卷曲并变得浓缩。
Nuclear envelope disintegrates.
核膜开始解体。
Gene transcription ceases during prophase and does not resume until late anaphase to early G1 phase.
基因转录在前期（prophase）期间停止，直到后期（anaphase）末期或G1期初期才会重新开始。
The nucleolus also disappears during early prophase.
核仁也在早期有丝分裂阶段消失。
Centrosome gives rise to mitotic apparatus i.e.
中心体是形成有丝分裂装置（即与有丝分裂过程相关的各种结构）的基础。
generation of spindle tubules.
纺锤体微管的生成过程。
METAPHASE Now all the pieces are aligning themselves for the big split.
**中期（Metaphase）**：现在，所有的“组成部分”都在为最终的“分裂”做准备。
The DNA lines up along a central axis and the DNA
DNA沿着一条中心轴排列。
has now condensed into chromosomes.
这些物质现在已经浓缩成染色体了。
Two strands of chromosome are connected at the centre with centromere.
两条染色体在中心通过着丝粒连接在一起。
The tubules connect to the centromere, not the DNA.
这些细管与着丝粒相连，而不是与DNA相连。
ANAPHASE Here we go!
**后期（Anaphase）**：开始啦！
The separation begins.
分离的过程开始了。
Half of the chromosomes are pulled to one side of the cell; half go the other way.
一半的染色体被拉向细胞的一侧，另一半则被拉向细胞的另一侧。
When the chromosomes get to the side of the cell, it's time to move on to telophase.
当染色体移动到细胞边缘时，就进入了末期（telophase）阶段。
TELOPHASE Now the division is finishing up.
**末期（Telophase）**：此时细胞分裂过程即将结束。
This is the time when the nuclear envelope begins to synthesize again along the separated chromosomes.
此时，核膜会沿着已经分离的染色体重新开始合成。
Cytokinesis pinches the cell membrane in the middle.
细胞分裂过程中，细胞膜会在中间被“挤压”（即发生变形）。
Cell membrane closes in and splits the cell into two.
细胞膜向内收缩，将细胞分割成两个部分。
Now, we have two separate cells, each with half of the original DNA.
现在，我们有两个独立的细胞，每个细胞都只含有原始DNA量的一半。
Up till now, we have discussed what is mitosis and its different phases.
到目前为止，我们已经讨论了什么是有丝分裂以及它的各个阶段。
Now it's important to know about significance of mitosis.
现在，了解有丝分裂的重要性非常重要。
SIGNIFICANCE It is an equational division through
**意义**：这是一种通过等式进行的除法运算。