Brain BREAK presents: Mitosis.
Occurs in somatic cells – your everyday cells. It’s the process of making two cells from one. A cell’s life cycle is much more than mitosis. Remember, it has a job to do, too!
The cell cycle consists of four notable stages.
G1: G is for “growth.” I consider this a “career” cell. A little cell says, “I’m so busy with my job!”. Who has time for kids? Not this cell. Work, work, work.
S: This is when DNA for a second cell is synthesized. S for synthesis. Our cell looks down lovingly as it knits DNA with its strands of chromatin, making a copy of all of its genes.
G2: The second growth stage, but this time, it is preceding mitosis. The growth in this stage refers to the mitochondria, cytosol, and all other cell components that it must replicate for its impending twin. It’s doubled DNA – now it must double everything else! The cell is swollen, saying, “It’s like I’m eating for two!”
Mitosis: The process that splits off a sister cell, after which the original cell returns to where it started at G1. Its twin cell will also start at G1. And the cycle begins anew!
While Interphase is sometimes called a stage of mitosis, it is G1, S, and G2 – most of a cell’s life. It takes a long time to make a copy of DNA and mitochondria, lysosomes…
Prophase – P for packing – is the breakdown of the nuclear wall and condensation of chromatin. In everyday DNA, this is the stage at which it can do its job making proteins and so on. Chromatin is uncondensed. When you think of chromatin, put those Ns together! Meanwhile, a chromosome is the super-condensed chromatin, packed into a tidy little box. When two identical DNA chromosomes prepare to undergo mitosis, we then call them sister chromatids.
Metaphase – M for middle – is the sisters aligning in the middle of the shared cell.
Anaphase – A for apart – is when the sisters start to split apart and move to their own sides. In diagrams, I think the separate chromosomes look like kielbasas. “Ana” is a young lady who loves to eat kielbasa. (Anabolism is a molecule growing larger. Which will happen if she eats too much)
Ana has a broad smile on her face as she readies a fork and knife. Her bib reads, “all you can eat.” Nearby, two chromosomes (or kielbasa sausage) fly apart.
Telophase is the sisters unpacking into chromatin again, each copy in its new nuclei. Though still joined, the two cells are stretching apart at the middle and each is now illustrated with its own face. One of the sisters says, “Stay on your side!” The other thinks, “Finally moving out!”.
-CNx