insect gas exchange Flashcards
1
Q
what is the disadvantage of a tough exoskeleton?
A
little to no gas exchange
2
Q
describe the spiracles
A
- holes in thorax
- allows gas exchange when water is lost
- opened and closed by sphinctors
3
Q
describe the tracheae
A
- lined by chitin spirals
- impermeable
- little gas exchange
4
Q
describe the trachioles
A
- elongated
- no chitin
- permeable
5
Q
describe tracheal fluid
A
limits air penetration
6
Q
what is mechanical ventilation?
A
thorax pumps air, changing volume and pressure
7
Q
what is the advantage of collapsible tracheae?
A
acts as reservoirs of air to increase the air moved throughout the system
8
Q
explain why water is always lost from the gas exchange surfaces of terrestrial organisms (2 marks)
A
- spiracles on surface of thorax allow water loss when air enters or leaves
- water is lost by evaporation
9
Q
abdominal pumping increases the efficiency of gas exchange between tracheoles and muscle tissue of the insect. why? (2 marks)
A
air is drawn into the tracheae and squeezed out which maintains a concentration gradient
