Friday, May 6, 2011

Mitosos and meiosis: the "and" and "or" in action

We see the "and" and the "or" at work in the process of both mitosis and meiosis.

Firstly, it might be worth noting that the "and" places a limit, not significant, the the degree of diversity that may appear through the imposition of rules.  Among these rules is that the nucleotide base "C" may only pair with "G" and the base "A" may only pair with "T".   DNA, as we know, consists of sequences of these pairs, millions or billions of pairs long.

In mitosis, each member of the pair, in essence, pulls away from each other.  In this pulling away and differentiation, we see an expression of the "or".  However, at the same time each base is pulling away from its partner, it is pairing up with another base, its complementary base, which is essentially the same base as its former partner.  Thus, with regard to the pair "CG", the "C" will pull away from its partner, "G" (the or), but partner with another G (the "and" in action).  Similarly, the "G" in the original pair pulls away from its initial partner (a "C") and will pair up with another "C" (the "and" in action once again.)  The new sequences of pairs fold around each other just as the old sequences.  Thus, in the creation of new sets of DNA, (and new cells which we won't describe), we see a predominance of the "and".

In the process of meiosis, gametes, which as I understand are eggs and sperm, are formed.  Each gamete, a single celled creature,  has half the number of chromosomes that the mother and father had.  In meiosis, as I understand, through a similar interaction of the "and" and "or" to that which occurs in mitosis, the chromosomes double and thicken. Then each pair of chromosones pair up with an essentially identical pair of chromosomes, called a homologous pair.  Then these cells are divided or pulled part into new cells not once but twice.   Thus, we see the operation of the "or" on two occasions.  A total of four gametes are made, each with half the number of chromosomes of the original cell.  Thus, in meioses, we see the predominance of the "or".

Of course, in sexual reproduction, two gametes come together to make a new cell with the original number of chromosomes, only a new assortment.  Thus, though in meiosis we see the predominance of the "or", in the combination of of gametes, we see a victory of both the "and" and the "or", in the form of greater diversity.  After the new cell is formed, it repeatedly reproduces, and the new cells are differentiated according to function (i.e. skin cells, blood cells etc.)  At this point we see an explosion of both the "and" and the "or", not dissimilar to that which took place at the time of the big bang.

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