116c suRvey # KH13

The earth consists of several layers. The three main layers are the core, the mantle and the crust. The core is the inner part of the earth, the crust is the outer part and between them is the mantle. The earth is surrounded by the atmosphere.The inner part of the earth is the core. The core is a dense ball of the elements iron and nickel. It is divided into two layers, the inner core and the outer core. The layer above the core is the mantle. into the inner mantle and the outer mantle. It is about 1,800 miles(2,900 km) thick and makes up nearly 80 percent of the Earth's total volume. The crust lays above the mantle and is the earth's hard outer shell, the surface on which we are living. In relation with the other layers the crust is much thinner. It floats upon the softer, denser mantle. The earth is surrounded by all kind of gases. This layer is called the earth's atmosphere. Without these atmosphere life on earth isn't possible. The atmosphere gives us air, water, warmth and is protecting us against harmful rays of the sun and against meteorites.

Egg Structure

It is composed of air cell, chalaza, yolk, yolk membrane or the vitelline membrane, shell membrane, shell, chalaza, thin or fluid albumen, thick albumen, and the germinal disc.

Air cell- forms at the wide end of the egg as it cools after being laid. The fresher the egg the smaller the air cell.
Yolk- the egg-s major source of vitamins and minerals, including protein and essential fatty acids.
Yolk membrane- surrounds and holds the yolk. The fresher the egg the stronger the membrane.
Chalaza- A pair of silent bands and anchor the yolk in the center of the thick albumen.
White(albumen)- there are two layers: thin and thick albumen. Mostly made of water, high quality protein and some minerals.
Germinal Disc- appears as a slight depression on the surface of the yolk.
Shell membranes- there are two membranes on the inside of the shell. One membrane sticks to the shell and one surrounds the white.