During the cool early spring, a queen bumblebee (Bombus terrestris) must raise her thoracic temperature to at least 30∘C30^\circ\text{C}30∘C before she can fly to forage. She achieves this by decoupling her wings from her flight muscles and shivering them rapidly. Her body is covered in a dense coat of insulating hair-like setae.
Explain why the queen bumblebee can be described as showing endothermic behavior.
Explain why it is much more difficult for a small insect, such as a bumblebee, to maintain an elevated body temperature compared to a larger mammal, such as a badger.
Gaseous exchange in insects is achieved via a specialized tracheal system.
Air enters and leaves this internal system of tubes through muscularly controlled valves located on the lateral sides of the exoskeleton. Name these pores.
Deep inside the body, the respiratory tubes branch into microscopic, highly branched tubules that contain fluid at their tips in direct contact with the respiring muscle cells. Name these specialized tubules.
Explain why large, highly active multicellular organisms require a specialized, mass transport system to distribute oxygen and metabolites, whereas single-celled or extremely small organisms do not.
A student is performing a dissection of a locust and wants to produce a high-quality, scientifically accurate biological drawing of the tracheal system associated with a spiracle. They have already used a sharp HB pencil to draw the diagram on plain paper and written a clear, descriptive title.
Suggest two other rules of biological drawing that the student must follow to ensure their diagram is clear and scientifically accurate.
