Cell Division

Cell division is when a cell splits into more cells, there are 2 types:

### Mitosis

The cell division of Body/Somatic cells ,this process **happens everywhere all the time** in the body **repeatedly** and produces **2 identical daughter cells**

### Miosis

The cell division of Sex/Gamete Cells, this process **does not repeat** and produces **4 unidentical daughter cells**

* Interphase
* Mitosis
* Check Points

Interphase is where cells spend most of its life doing their jobs, interphase is separated into 3 stages:

* **G1** - Cell Growth

* **S/Synthesis** - DNA Replication

* **G2** - Growth and replication for cell divisions

Each of the stages are explained further in the tabbers below:

* G1
* S
* G2

G1 is where the cell grows after going through mitosis, after mitosis the cell needs to grow as after replication its parts are not up to their full size

### G1 Checkpoint

This checkpoint happens towards the end of G1 in interphase where 3 things are checked:

* Checks if there are adequate resources for the cell to divide such as proteins required for mitosis, and cell size

* Checks if the cell is large enough to divide

* Checks if the DNA in the Nucleus has been damaged

if these checks are passed then the cell can move up the cycle, if not they cant move up the cycle
S phase also known as synthesis is where the DNA is replicated, DNA is replicated so that when it goes through mitosis, the DNA for each daughter cell is identical

G2 is where the cells Grow and Replicate DNA to prepare for Mitosis as this step is the last step of phase of interphase before Mitosis starts, the cell needs to be in good shape and have exact copies of DNA to make sure that 2 daughter cells will successfully be created

### G2 Checkpoint

This checkpoint happens before the end of G2 in interphase where 3 things are checked:

* Checks if there are adequate resources for the cell to divide such as proteins required for mitosis, and cell size

* Checks if DNA or Chromosomes have any replication or damage

If these checks arent passes then the cell wont move up to the Mitosis cell phase

The process of a body/somatic cell dividing into **2 identical daughter cells**, the process is split into 4 main stages:

* Prophase

* Metaphase

* Anaphase

* Telophase

and finally the cells split into 2 from Cytoknesis

### Spindle (M) Checkpoint

This checkpoint evaluates whether all the sister chromatids are correctly attached to the spindle mircotubes

* This checkpoint occurs before Mitosis

* Checks all spindle fibres have replicated without mistakes or damage

each of the main phases are explained Below in the following tabbers:

* Prophase
* Prophase
* Metaphase
* Anaphase
* Telophase
* Cytokinesis

Prophase is the stage where (add info), there is 2 phases of Prophase

### the M/Spindle fibre checkpoint

This checkpoint happens before the end of Metaphase in mitosis and checks for 2 things:

* checks if all the spindle fibres have replicated without mistakes or damage

* Checks if all the sister chromatids are attached and lined up in the middle, if not then the cell cannot move up to the Anaphase stage

Cytokinesis is final stage where the cell splits into **2 identical daughter cells**.

### Checkpoints

Before mitosis there are also check points that check if the steps have been done properly, if a step hasn't been done then a repair will be done, check points are explained below and are there to make sure everything goes right if not then cell death happens

* G1 Checkpoint

* G2 Checkpoint

* M/Spindle fibre Check Point

### Trivia

* Controlled cell break down is called Apoptosis

* Accidental Cell death is called Necrosis

The information on the checkpoints are listed in the tabbers below:

* G1 Checkpoint
* G2 Checkpoint
* M/Spindle Fibre Checkpoint

This checkpoint happens towards the end of G1 in interphase where 3 things are checked:

* Checks if there are adequate resources for the cell to divide such as proteins required for mitosis, and cell size

* Checks if the cell is large enough to divide

* Checks if the DNA in the Nucleus has been damaged

This checkpoint happens before the end of G2 in interphase where 3 things are checked:

* Checks if there are adequate resources for the cell to divide such as proteins required for mitosis, and cell size

* Checks if DNA or Chromosomes have any replication or damage

If these checks arent passes then the cell wont move up to the Mitosis cell phase

This checkpoint happens before the end of Metaphase in mitosis and checks for 2 things:

* checks if all the spindle fibres have replicated without mistakes or damage

* Checks if all the sister chromatids are attached and lined up in the middle, if not then the cell cannot move up to the Anaphase stage