During a windstorm, a large old tree fell in the forest. As it came down, it trapped a young sapling about 5 meters tall underneath it. The top of the
Auxin and gibberellin in the sapling's stem will cause a gravitropic response in the sapling, and its stop will grow upward even though it is held down.
It might change over time to compensate fir its environment
Expansive basically means the same thing