Mitosis is an essential process in the lives of cells, as it
allows them to replicate (become two individual cells). This is a highly
regulated process, as there a lot of things that need to be doubled before
either 'daughter' cell can exist independently. During mitosis, the DNA of a
cell is distributed equally among daughter cells. However, before this can
happen, the cell needs to double in size, double all of its organelles
(cell organs) and, most importantly, make an exact copy of its DNA. As you can
imagine, keeping track of all this doubling can get confusing, so scientists
have found a way to subdivide this whole process into several distinct steps.
These include interphase, Gap1 (G1), Synthesis (S), Gap 2, and finally,
mitosis. Most of you will have covered all of this in your school years, maybe
in a time long-forgotten, or maybe you are stuck trying
to memorize it now. But before you turn away in disgust
(bleargh, biology) and contemplate clicking onto the next more frivolous web-site,
I ask you this: have you ever wondered what mitosis would feel like?
For the school students, who are wondering
'what is the point of learning this since I will never use it again in my life',
I have included some simplified biology details that should help you pass your
dreaded biology exam. Hang in there, soon you will be part of the people who
can comfortably forget biology details without any significant consequence to
their lives.
The Gap
1 (G1) phase, is the step
that comes after interphase. Essentially, all that happens in G1 is that the
cell increases in size and gets ready for DNA replication. To do this, the cell
increases its supply of proteins and number of organelles, such as mitochondria
(the cellular equivalent of lungs, they breathe and use the oxygen to produce
energy) and ribosomes (essential to the cell as they make protein). It can
last a variable amount of time.
I waited and waited in the gloom. My body
seemed to grow with the drumming of the heart-beat. But I was darkness and I
was barely aware of my size. I was anger, and disappointment and pain. I wasn't
any different from my fellow cancer cells. I was a monster, too. I let myself
sink deeper into my misery. I didn't deserve an escape. I felt my sides push
against my neighbouring cells, and I let them, revelling in the feeling of
discomfort. I don't know how much time had passed as I grew, impassive. It
could've been hours, or minutes, or days. Time seemed to have lost its value,
as it led me to my atrocious fate. Abruptly, everything stalled. I glanced
down, disinterested, noticing how my inside organs seemed to have doubled.
Maybe I had finally lost my mind, and I was just seeing double. I noted I was
huge, towering over my fellow cells. I wondered if this was how Hulk felt on a
daily basis. I briefly wondered if I should feel some sympathy for him, and
then remembered I didn’t care.
The synthesis (S) phase, is the stage
where the DNA is replicated. On any other day, a cell’s DNA looks like a bowl
of spaghetti. You can imagine how hard it would be to pick out individual
spaghetti pieces and try to duplicate them without making a mess (please do not
try this at home). Cells have found a way to ‘tidy-up’ the DNA into chromosomes
just for this purpose. Essentially, they make the bowl of spaghetti look like
baguette bread loafs. Each bread loaf (chromosome) is duplicated and then left
to lie next to the original baguette. To avoid making a new mess, and
forgetting what’s what, each baguette copy is tied to the original with a
tooth-pick in its centre (scientists call this the ‘centromere’). When two
baguettes(chromosomes) are tied like that, scientists like to call them ‘sister
chromatids’, because they want to confuse you. You can call them ‘brother
baguettes’ to get right back at them. DNA
synthesis (replication) is completed as quickly as possible, so as not to
expose the fresh baguettes to mutagenic factors before they are completed. Mutations
cause cancers. Cancers are bad.
I suddenly realised there was a
faint cheering in the background. Scours of cancerous evil eyes were watching
my progress, elated. I felt nauseated, and attempted to return to the
blackness, the numbness. I closed my eyes, and revelled in the feeling of the
oxygen seeping into my pores. But the solace of darkness didn't envelop me.
Instead, I felt a faint tugging in my nucleus. The nucleus contains the DNA,
like a skull would a brain, if I were human. It controls our every move,
our every thought. I guess the feeling I was experiencing could be compared to
a migraine, or a strong headache. The pain jolted me out of my depression, and
I grimaced, confused. I tried in vain to ascertain what was happening inside my
nucleus. But like a man wouldn't be able to look into its own brain, I was
unable to make the slightest progress. The pain got stronger, clouding my
brain. Every thought had to travel through a thick fog before becoming
coherent. I tried to shake my head, but realised I couldn't. I had no head. I
was a cell. A sticky, huge cell, who couldn't budge. The nearby cancer cells
seemed to notice my discomfort, and started cheering louder. 'Here comes the
DNA synthesis' one cell said, ecstatic. Her words raced through my muddled
thoughts, their meaning sinking into the depth of my soul. The fear they
brought was stronger than the pain. Survival instincts kicked in, as I realised
I was about to have two sets of DNA, a second brain. I was about to become two
cells. I wondered in horror, whether I would lose myself as I became two. Was
this the end of me? 'I'm not afraid.' I thought. 'I'm not afraid, I'm not
afraid, I'm not afraid.' I repeated these words over and over in my mind,
clinging to their meaning, chanting them to the fear that was slowly building
at the edges on my mind. But I wouldn't, I couldn't let it win. If I was to go
as a monster, I wouldn't let myself be a coward too. The edges of my thoughts
were becoming clouded, and I chanted, louder and louder, challenging the pain,
resisting my nature. But the clouds didn't recede, and I realised with a jolt
that my thoughts had now become weak whispers of fear, as I mumbled 'I'm not
afraid' one last time. I felt a final blinding tug in my nucleus, as if my
brain was being opened up and split into two, and I felt myself sink into the
darkness. Through the rumbling in my ears I thought I heard a pleading voice,
clear as an angel, whisper my name. 'Selena.' I thought. And then it all went
black.
The Gap 2 (G) phase, is just a gap between
DNA synthesis and mitosis. Impossibly, the cell continues to grow in size.
I slowly slipped back to consciousness,
faintly aware of a strong pain gradually subsiding. My thoughts were still
muddled, and I noticed there seemed to be an echo to the voices within me. I
felt like I was screaming inside an empty cave, my every scream doubled back at
me. As if sound was looking at itself in the mirror. I tried to recall what was
happening, but thinking was becoming so hard. There seemed to be too many
thoughts conflicting with each other...Like two minds in one body. This
realisation hit me like a lightning bolt, and I understood that my cloudy state
of mind was due to me having one nucleus with two sets of DNA, like one head
with two brains. Both of my minds froze in unison. Then, a faint pressure on my
membrane broke me out of my reverie: impossibly, I was still getting bigger.
I felt a second part of me rejoice in the notion of splitting. Like I had
somehow unearthed an evil side. I got muddled up in a mixture of happiness and
awe, terror and fear. When would this nightmare end? I closed my eyes again,
attempting to clear my mind. I longed for the silence, for a mind at peace.
There were too many thoughts, too many evil thoughts. I felt crowded. And then,
as abruptly as it had stopped, the pain seared again.
