Final answer:
An average living adult has about 4.7 to 5.7 liters of blood, based on body weight, with males having more than females. Blood plasma, mostly water, comprises over half of this volume, containing proteins and other substances essential for body functions.
Step-by-step explanation:
The average living adult has approximately 4.7 to 5.7 liters of blood. This accounts for about 8 percent of the adult body weight, with adult males averaging around 5 to 6 liters of blood and females averaging 4-5 liters. More than half of the blood volume is fluid, predominantly water.
Blood plasma makes up a substantial portion of this fluid and consists mainly of water, being about 92 percent water. It contains a variety of dissolved substances, a large proportion of which are proteins. The blood not only acts as a critical transport system within the body but also regulates pH and water levels, through organs like the kidneys.