eli5 / if DNA codes for proteins, but each type of cell uses different proteins, how do the cells know which bits to use? Furthermore, how does that also translate to larger scale shapes in/on the organism? (Like the shape of my face, or the shape of a plants leaves)

Question

eli5 / if DNA codes for proteins, but each type of cell uses different proteins, how do the cells know which bits to use? Furthermore, how does that also translate to larger scale shapes in/on the organism? (Like the shape of my face, or the shape of a plants leaves)

In: 7

Answer 1

Have you ever played these “choose your own adventure” game books? Where everytime you have to make a decision you choose a page and read a specific part of the text? Development kinda works like that. The book is our DNA, and the decisions are small signals that “tell” our cells who to become during development, and they “learn” how to “always” follow the same instructions. So it’s like, every cell has the entire instruction manual inside, but the order of instructions to be followed, thus the end result, varies depending on the type of cell.

(there are exceptions etc., I tried to make it as simplified as I could)