Final answer:
The incorrect characteristic of blood among the options given is that its pH varies between 7.15 and 7.25. In reality, the pH of blood ranges from 7.35 to 7.45, which shows that blood is slightly more alkaline than pure water.
Step-by-step explanation:
The characteristic of blood that is NOT accurate is option 3) The pH of blood varies between 7.15 to 7.25. The correct pH range for blood is 7.35 to 7.45, indicating that blood is somewhat more basic (alkaline) than pure water, which has a pH of 7.0. Blood's color indeed varies from scarlet red to dark red depending on the oxygen saturation. Blood's temperature is slightly higher than the body's temperature, usually around 38°C (100.4°F) compared to the body's 37°C (98.6°F), and blood is also thicker (more viscous) than water. Therefore, blood does have a range of characteristics that help it fulfill its roles in the body such as regulating pH, temperature, and transporting substances needed for homeostasis.