Final answer:
In most insects, gas exchange is accomplished by a tracheal system, a network of chitin tubes that facilitate direct oxygen transfer to the body's tissues through spiracles.
Step-by-step explanation:
In most insects, gas exchange is accomplished by a tracheal system. This highly specialized respiratory system consists of a network of small tubes made of polymeric material called chitin. These tubes, which are called tracheae, extend throughout the insect's body and are directly connected to cells for gas exchange. The major tracheae open to the surface of the insect's body through apertures known as spiracles.
The tracheal system allows for a direct and efficient transfer of oxygen to the body's tissues and is independent of the insect's circulatory system. Therefore, the insect's blood does not play a direct role in oxygen transport. It's notable that this type of system allows insects to sustain high levels of activity due to its efficiency in gas exchange.