75 utenti della rete avevano questa curiosità: Spiegami: How the bones know the exact shape that they need to be formed and don’t become glued with the other bones close of them?
Spiegami: How the bones know the exact shape that they need to be formed and don’t become glued with the other bones close of them?
Ed ecco le risposte:
Your DNA is like a blueprint that defines where everything needs to go. It’s like the directions in a lego set only all the lego pieces have the instructions and can move themselves into place.
This isn’t technically correct because development is kind of complicated.
While a fetus is developing the cells create a gradient of signals. Using these gradients a cell can “tell” back/front, top/bottom, and left/right.
Things like arms start off as buds and when it gets further away from the torso the gradient turns the cells from “make more bone” to “make the end of the bone” to “make some stuff in-between” to “make next bone”.
As other comments said this gradient of signals turns DNA on and off.
I’d like to add a fun fact about development: When someone has an extra finger, this gradient was messed up by something. However, your DNA only has plans for 5 fingers, so instead of a new finger you really only have another copy of one of your other fingers.