Insects Gas Exchange

Question 1

Briefly outline the tracheal system in insects

Answer 1

Gas exchange involves a tracheal system
Spriacles are openings where co2 leaves and o2 enters the insect
Trachea - a network of tubes with rings to strengthen them and stop them from collapsing
Tracheoles are branched off from the tracheal and extend to deliver oxygen to respiring cells

Question 2

What provides a short diffusion pathway in this system

Answer 2

Tracheoles are in direct contact with insect body cells
Insects are small maintaining an overall short diffusion pathway from spiracles to respiring tissue
The Tracheoles have thin walls

Question 3

What maintains concentration gradient

Answer 3

The cells respire using oxygen so the concentration of oxygen in cells remains low

Question 4

What gives a large surface area

Answer 4

The Tracheoles being branched

Question 5

What’s abdominal pumping

Answer 5

It’s a ventilation mechanism
A compressed abdomen increases pressure (compared to atmospheric)
Air containing higher levels of CO, is forced through the abdominal spiracles out of the tracheae
An expanded abdomen lowers pressure (compared to atmospheric)
Air containing higher levels of 02 is forced through the thoracic spiracles into the tracheae

Question 6

How does the anaerobic respiration of an insect help maintain concentration gradient

Answer 6

When the insect is in flight mode the muscle cells respire anaerobically to produce lactase
This lowers water potential of the cells
Water moves in from the Tracheoles into the cells by osmosis this drecreases the pressure and volume in Tracheoles
And more air moves in from the atmosphere

Question 7

how does it prevent water loss

Answer 7

spricales close
exoskeleton is impermeable
spiracles have hair in them
the waxy cuticle