So I tackled 2.2.2 Biology tonight - and realised that fittingly it's the middle section of the whole album. Appropriate then that I had the thought of using a heartbeat rhythm. To be honest when I started that was really all I had.
So I used a bass drum gentle pulse to give a... well pulse. I then wondered what it would be like with a real heartbeat sound effect instead. I found one, and manipulated it to the right speed, and then actually found that it was nice when I combined the drum pulse with the real pulse.
Because I was doing biology I wanted feelings of growing, feelings of strength and solidity, and also feelings of delicateness and gentleness - all the sorts of things we think of for nature. I guess you could say what I got happened "organically" although I hate that mis-use of the word. I played with synth sounds, one giving a gentle rising, one with wide, broad strong yet gentle chords, and then a couple of rhythmic ones. I blended one into another, into another and stripped it back to the pulse and a rhythm synth - towards the end bringing in a gentle enigmatic piano. All of this over a long D note - actually that note carries through all three science sections.
At times this is quite "experimental" - meaning chaotic. Again this appeals to my idea of biology.
So this slots in before 2.2.3 chemistry, and as I write I am listening to the sequence. I seem quite convinced so far.