Which of the following is true regarding blood composition?

The statement that blood is 80% water is true and reflects the significant role that water plays in blood composition. Blood is a complex fluid that consists of various components, with plasma making up about 55% of its total volume. Since plasma is primarily composed of water, this contributes to the overall water content of blood. Water serves as a solvent for various substances, aiding in the transport of nutrients, hormones, and waste products throughout the body.

In addition to water, blood contains cells such as red blood cells, white blood cells, and platelets, which account for the remaining 45% of its volume. While these cellular components are crucial for functions like oxygen transport and immune response, the majority of blood’s composition is indeed water, highlighting its importance for maintaining blood's physical properties and physiological functions.