Final answer:
Blood is a good indicator for the metabolic activity in all tissue and the oxygenation ability of the lungs.
Step-by-step explanation:
Oxygenation ability of the lungs and metabolic activity in all tissues can be indicated by blood. Blood carries oxygen from the lungs to the tissues and can be used to measure the level of oxygen in the body. By measuring the oxygen levels in the blood, we can determine the metabolic rate of a person or animal.
A pulse oximeter is an apparatus that measures the amount of oxygen in the blood, which can be used as an indicator of metabolic activity and lung function.