What are the 2 purposes of the air cell in a chicken egg?

Answer 1

Air cell
The larger end of the egg contains the air cell that forms when the contents of the egg cool and contract after it is laid. Chicken eggs are graded according to the size of this air cell, measured during candling. A very fresh egg has a small air cell and receives a grade of AA. As the size of the air cell increases, and the quality of the egg decreases, the grade moves from AA to A to B.
Egg characteristics
The shape of an egg is an oval with one end larger than the other end. The egg has cylindrical symmetry along the long axis.

An egg is surrounded by a thin, hard shell. Inside, the egg yolk is suspended in the egg white by one or two spiral bands of tissue called the chalazae (from the Greek word khalazi, meaning hailstone or hard lump.)

Shell and its color
Main article: Eggshell
Egg shell color is caused by pigment deposition during egg formation in the oviduct and can vary according to breed, from the more common white or brown to pink or speckled blue-green. Although there is no significant link between shell color and nutritional value, there is often a cultural preference for one color over another. For example, in most regions of the United States, eggs are generally white; while in the northeast of that country and in the United Kingdom, eggs are generally light-brown. In Brazil, white eggs are generally disregarded as industrial, and red or light blue eggs are preferred. Regarding chicken eggs, the color of the egg depends on the color of the bird. According to the Egg Nutrition Center, hens with white feathers and earlobes will lay white eggs, and chickens with red feathers and earlobes will lay brown eggs.[2]

Abnormalities

Three eggs frying, two of which are double-yolked eggs.Some hens will lay double-yolked eggs as the result of unsynchronized production cycles. Although heredity causes some hens to have a higher propensity to lay double-yolked eggs, these occur more frequently as occasional abnormalities in young hens beginning to lay.[citation needed] Usually a double-yolked egg will be longer and thinner than an ordinary single-yolk egg. Double-yolked eggs occur rarely, and will only lead to the successful development of two embryos with human intervention.[3]

It is also possible for a young hen to produce an egg with no yolk at all. Yolkless eggs are usually formed about a bit of tissue that is sloughed off the ovary or oviduct. This tissue stimulates the secreting glands of the oviduct and a yolkless egg results.

Answer 2

Air Cell Egg

Answer 3

I believe in evolution, so i believe the egg came first. This comes from the theory that birds evolved from the dinosaurs. So, a dinosaur lays an egg and a chicken comes out. Of course this process would take a longer time than just one egg laying.