When the matrix is activated it transfers some base information on the personality, (we've seen that other things is ussually programmed later on, or by another transformer, ie Prime saying he's programming the Aerial-bots, and such other notions of acctual programmers within the race) but the introduction of Sparks and protoforms (asexual division too, we'll talk about that later) gives it another aspect.
The spark, is apparently a light-like metaphysical core of information, the spark contains information on the subjects core personality, but also physical properties, as apparently protoforms infused with sparks take on some physical parameters, a bit like DNA works for us organisms.
This Transformers hereditary mass, is apparently copy-able and editable, as have been seen with various clones, and even the Matrix-Prime bonding-process, as it transmutes the Transformer connected to it, if necessary, to a sort of "Ultimate Transformer", looks rather similar to genetic engineering to me.
Theoretically, the light-energy in there sparks contain information as to how the nanotech components that make out their bodies is to form, similar again, to how organisms evolve/functions.
The Bio-morphic division process!

We know now that the first transformers werent created trough the time-consuming process of Matrix-energy infusion and body-designing, but rather trough a process similar to how primitive organisms reproduce, division. One Transformer divides into two, and so on.
Now, apparently the division must be in the spark-information too, partially. Spark divides into two, whereas one is identical to the original, and the other mutates slightly, or in some cases, massively, creating a different individual. This individual can have similar physical properties and personality as the donor, such as Optimus Primal/Optimus Prime.
Apparently this divison can happen before the spark has any body to program, as in the MTMTE profile-books we are told that when you "load" a spark from the matrix/matrix Flames/Vector Sigma, and transfer it on it's way to a proto-form it can, rarely, divide spontaneously, and then have to be transferred into two protoforms instead of one, this ussually results in two transformers with similar properties/personalities, such as Sunstreaker & Sideswipe.
This "DNA", can also apparently become "inbred", mutated and damaged, such as the G2-Tf, who both look and behave quite differently from normal Transformers.
In the G2-comic we also acctually got to see this hereditary mass in up front, on a hologram, when the Autobot scientists claim that The Swarm has a "genetic structure similar to a Transformers".
And apparently this "DNA" works somewhat different than the organic ones we have on earth. Rather than one, big ordered strain of information, tf-dna looks as if it has several loose parts, modules wich can connect and then reposition itself, and quickly make a different pattern, an on/off system for various feats.
Is this the core of Transformation gentlemen, or have I simply read in too much of this one panel or misinterpreted it?
Now, does anyone have any comments on these "facts" wich I've stated, or perhaps something to add?
