Other Biology Flashcards
1
Q
What prevents insect tracheae from being crushed?
A
Spirals of chitin surround each trachea.
2
Q
Why are tracheae very impermeable to gases?
A
The spirals of chitin that keep tracheae open are impermeable to gases.
3
Q
How can insects increase the rate of gas exchange during exercise other than through mechanical ventilation?
A
During heavy exertion, lactic acid builds up in the muscle cells, causing water in the tracheoles (tracheal fluid) to move into the cells by osmosis, increasing the surface area of the tracheoles available for gas exchange.
4
Q
How do larger insects meet their higher demand for oxygen supply?
A
- Movement of air into and out of the tracheae / tracheoles by muscles in the body. Movement causes the volume in the tracheae to change, causing pressure to change, causing air to move in and out. (Mechanical ventilation)
- Air sacs, inflated and deflated by movements in the thorax / abdomen.
5
Q
How does oxygen diffuse through tracheoles in insects?
A
Oxygen dissolves in water on the walls of tracheoles, then diffuses into the surrounding cells.
