Question

what does first come egg or hen

Answer 1

First hen came , because the protein in the eggshells can only be synthesized by a hen . A protein - called ovocledidin-17, or OC-17 - acts as a catalyst to helping in growth of the eggshell.This protein is secreted only by a hen's ovary.

Answer 2

Hen came first because the protein in the eggshells can only be synthesized by a hen  called ovocledidin-17, or OC-17 - acts as a catalyst to helping in growth of the eggshell .This protein is secreted only by a hen's ovary.

hope it helps you