vestigial
dead cells
Evolution
This is because it is oxygenated blood, filled with nutrients to begin with and as it runs through your whole body, it distributes these to different parts of the body. Once its circulated your whole system. Its de-oxygenated and so loses some of its pigment
The function of blood is what it does in the body (carries O2, CO2, food, hormones water etc.) and the circulation of blood is how it gets round the body (pumped by the heart through arteries and veins) to perform its function.
It's the skin. Stomata are pores in the plant leaves through which water vapour escapes the plant. The human body loses water in the form of sweat through the sweat pores in the skin.
The main function of the digestive system is to get the food and water you drink through your body.
The body becomes dehydrated. Lack of water and body salts will affect body and brain function.
3to 5% of body weight
Because sweet is the body's function to cool you down. The runner could overheat and pass out.
Evolution
No, souls are from a religious body. There is no way to tell that souls exist or not. I believe they do but there is no way that evolution made souls.
5-6
Electrolytes.
The function of the blood vessel is to pass oxygen through the body via the blood.
The main function of the heart is to pump blood through the body.
Pumps blood through body!
To circulate blood through the body.
The heart has only one major function. This function is to pump blood through the body and to and from the lungs.