While biological structures are ultimately 'DNA-controlled', the translation of the ACTGs to codons to proteins to structures explodes in complexity. Even within that simple molecular (i.e. no microstructures, let alone macrostructures like the whole cell) realm, everything is influencing everything else all at once. Proteins will suppress or enhance transcription of others, alter how other proteins are synthesized, and so on.
Once you have some molecules/proteins, they'll assemble into microstructures controlled by other proteins and small molecules that can push/pull on 'things', and they'll be influenced by the ambient conditions: temperatures, pHs, mineral contents which they're not fully in control of, but they're the progeny of ancestors that have been doing it for millions of years in the same habitat, and they've been trained and optimized to handle those varying conditions, so they get it right most of the time.
The biology then interacts with physics and chemistry to kinetically grow faster here to make something grow outwards, slower here to make it grow inward, then you can start forming shapes.
Once you have some molecules/proteins, they'll assemble into microstructures controlled by other proteins and small molecules that can push/pull on 'things', and they'll be influenced by the ambient conditions: temperatures, pHs, mineral contents which they're not fully in control of, but they're the progeny of ancestors that have been doing it for millions of years in the same habitat, and they've been trained and optimized to handle those varying conditions, so they get it right most of the time.
The biology then interacts with physics and chemistry to kinetically grow faster here to make something grow outwards, slower here to make it grow inward, then you can start forming shapes.