Gas exchange in insects

Insects (terrestrial organsisms) have evolved to conserve water.
The increse in surface area conflicts this.

For gas exchange, insects have evolved an internal netwrok of tubes called trachae. They are supported by strengthened rings to prevent them from callapsing. The trachae divide into smaller dead-end tubes called tracheols. They extend htroughout all the body tissue. This way oxygen is bought directly to the respiring tissues, due to the short diffusion pathway from a tracheole to a body cell.

Respiratory gases move in and out of the tracheal system in 3 ways:

• Along a diffusion gradient- When cells respire, oxygen is used up and so its concentration towards the end of the tracheoles falls. This creates a concentration gradient, that causes gaseous oxygen to diffuse…