If you centrifuge (spin) whole blood you will find the band of white blood cells and platelets (the buffy coat) is much thinner than the packed red blood cells below it. this difference reflects the fact that

blood contain more red blood cells and less white blood cells

Explanation:red blood cells percentage 45%

There is a higher concentration of red blood cells in blood, as opposed to any other cell type

Explanation:

In blood, there are different components.

Cellular: containing red and white blood cells

Platelets: These are particles found in blood that allow your blood to clot when you get a cut. If platelets are absent from blood, then even the smallest of cuts will not stop bleeding

Plasma: This constitutes of most of the blood components because this is the fluid that transports the other components around the body.

The reason that the red blood cell's component in the centrifuged sample, is that most of the solids travelling in the body are red blood cells

explanation:

the fossil record extends back to a dog-like ancestor some 55 million years ago, which gave rise to the first horse-like species 55 to 42 million years ago in the genus eohippus.