God.
the chick develops on the edge of the egg yolk (the yellow part) as it grows, the chick absorbs the nutrients from the yolk into it's body as food.
No, an egg shell will not expand as the chick grows, once the chick has 'outgrown' its shell it starts to chip a small hole in the shell, then begins to break out into its new world.
An unhatched hick develops a hard 'shell tooth' by the time it is ready to hatch and uses it to tap against the inside of the shell until it makes a small hole. The chick then pecks at the edges of the hole to enlarge it until the opening is large enough for it to escape from the shell.
So the growing chick inside gets air to breathe.
No not really. Sometimes it looks like a bubble when the chick first breaks through the shell. That bubble is just a rubbery membrane under the shell. Sometimes when you peel a boiled egg you will find this between the shell and the egg inside. The chick sometimes has trouble poking through this membrane and it can look like a bubble as the chick tries to force its way through..
The lungs of the developing chick are not formed or functioning until day 19 of incubation. The use of the albumen within the shell for the embryo allows room for air to gather as absorbed by the porous shell. That small amount of air is enough for the chick to use until the egg tooth opens the shell. This is one reason a double yolk egg fails to fully develop.
At the tip of a chicks beak is a small sharp bump called the egg tooth. The chick uses this "tooth" to put pressure in the shell from the inside making a small hole for air and then a series of cracks. This process can take 24 hours or more. The chick comes out of the shell with this egg tooth intact but it soon is absorbed as the beak grows and the chick get older.
The developing chick feeds on the yolk sac, much like the baby of live bearing animals attaches to the placenta. The chick has enough nutrients when born to got 24 hours without beginning on chick starter.
Like all embryos, a chicken in the egg does not require air to breathe until such time (approximately day 19) when their lungs develop enough to use the small amount they need. When it is first laid, the egg is full of yolk and albumen. At that time there is no air space as it is not required. The egg shell is porous. Moisture is lost through the shell over time and the moisture is replaced by air. When we breed chickens on the farm, we keep the small end of the egg up so the air collects above the developing chick. This air will be used by the fully formed chick inside the egg while it "PIPS" its way out of the shell at day 21.
The developing chick feeds on the yolk sac, much like the baby of live bearing animals attaches to the placenta. The chick has enough nutrients when born to got 24 hours without beginning on chick starter.
This is not possible. For the chick to break the shell, it must first break the membrane.
No Inside the shell are two membranes,the inner membrane directs blood flow to the chick and the outer membrane retains moisture. The chicks pipping from the inside with the egg tooth is done slowly and controls the ceasing of that blood flow. Done Too quickly and the chick will die. Unless the chick has already made the first tiny hole to the outside there is no way you can tell where the chicks head is located, opening the shell at its tail will have no good results ,only bad. Cracking the shell will result in the death of an otherwise possibly viable chick.