Innerspace Adventures Through the Human Body
Episode Three: Mitosis
On last week’s episode, we continued to investigate the Cell Cycle, looking at the importance of the Interphase. This time, we will be seeing how and why Cells divide in this week’s exciting installment of Innerspace Adventures Through the Human Body!
The title sequence provides a brief visual summary as to how the human body is represented as a space age society, with each different element playing specific roles that can be compared to similar roles in reality, such as the emergency services etc. The sequence ends with the words “Innerspace Adventures Through the Human Body!” across the screen.
FADE IN and PAN OVER a bustling highway of fast moving objects.
This bustling highway is the human bloodstream, the regular route of travel for many Cells, specifically, Red and White Blood Cells.
A Bacterium enters the bloodstream and is seen swerving violently through traffic.
Every so often, there are trespassers in the bloodstream and this is where White Blood Cells come in handy.
INT. Bone Marrow ‘Police Station’
CUT TO CLOSE UP of sign that reads “Bacteria Detected in Bloodstream”, accompanied by flashing lights and sirens.
A Hematopoietic Cell emerges from a garage.
White Blood Cells start of as Hematopoietic Cells in the Bone Marrow.
The Hematopoietic Cell moves through a device which speeds up the maturation process.
These Hematopoietic Cells grow and mature to become White Blood Cells. The next step is Mitosis, where the White Blood Cell divides and increases its numbers in order to tackle bigger threats.
CUT TO ABOVE White Blood Cell. A large magnifying device enters off screen, magnifying the dome on the White Blood Cell and showing the genetic material within. The camera moves in, transitioning into the Mitosis sequence.
INT. White Blood Cell
Mitosis takes place over several phases.
First of all is the Prophase, where the chromosomes coil up and condense. This makes them shorter and thicker, and the nuclear envelope containing them is broken down. The separate copies of a single chromosome are known as sister chromatids. Spindle fibres are formed whilst centrioles move to either end of the Cell.
The next step is the Metaphase. The chromosomes line up in the centre of the Cell. Microtubules formed during the Prophase attach to the sister chromatids.
The sister chromatids begin to separate, this is the beginning of the Anaphase. The sister chromatids are held together by the centromere, which begins to divide as each sister chromatid, moves down its spindle fibre.
The final step is the Telophase, in which the two now separate groups of chromosomes reach opposite sides of the Cell. Both groups gain a new nuclear envelope and the chromosomes uncoil.
Camera PULLS BACK from Cell, returning to an exterior view of the Cell, the door to the Police Station garage opening in the distance.
The division is finalised through a process known as Cytokinesis, where the cytoplasm and organelles divide. The completed processes of Mitosis and Cytokinesis result in two separate cells that are genetically identical, known as daughter cells.
The White Blood Cell divides into two and speeds out through the now open garage door.
These daughter cells are free to duplicate further before they go on to fulfil their specified tasks.
The White Blood Cells are seen entering the bloodstream from the Police Station. They begin to speed down the bloodstream, moving through traffic and eventually catching up to the Bacteria. One of the two Cells swerves in front of the Bacteria, cutting it off and bringing the pursuit to a halt. The camera pulls back as the sirens continue to whirr and the shot fades out to the credits.
Next time, we’ll be investigating specific Cells and their roles in the Human Body. Make sure to tune in for more exciting Innerspace Adventures Through the Human Body!