So, I’m still not understanding this whole “seed” thing, for which I blame men. Ha, just kidding. Seeing if you were paying attention. But I was partially confused, I think, by the conflation of “seed” with, you know, men’s seed.
But a seed, it turns out, is more like a fertilized egg. There’s a shell of some sort, food to fuel the tiny plant embryo, and, thus, a tiny plant embryo.
I will wait here while you contemplate the incredible cuteness of a teensy tiny little plant embryo.
As for how the seed knows to kick that embryo into growing-gear, I’m still not sure.
I’m still going to assume that part’s magic.
Tiny Cat Pants 
Part of it’s energy, at least. Energy accumulated from processing the food in its little case and water and soil minerals and such. Enough energy and – time to grow!
But that’s like the same as magic.
Seeds are created in the flower when the pollen from another flower (unless it’s self-fertilizing) gets onto the pistil. Google “flower parts” for a diagram. The seed stores its energy but it’s also using it, to some extent, and is drying out while it waits for Spring (or Spring-like conditions). It’s why seeds you buy (or collect and save) will eventually dry up and do nothing. They’ve used up their energy and dried out too much. Warmth and moisture tell it to get growing. All of this being my totally unscientifically trained knowledge. A biologist could tell it better but with bigger words.
Pingback: A long, slightly rambly mid-week gardening interlude | theology&geometry