gas exchange in insects

Question 1

what are trachea

Answer 1

internal network of tubes in insects

Question 2

how are trachea supported

Answer 2

by strengthened rings to prevent them from collapsing

Question 3

what are tracheoles

Answer 3

smaller tubes that trachea divide into
extend through all body tissues
ends are filled with water

Question 4

what are the 3 ways respiratory gases move in and out of tracheal system

Answer 4

along diffusion gradient
mass Transport
osmosis

Question 5

describe how respiratory gases are transported along the diffusion gradient

Answer 5

o2 from atmosphere diffuses along trachea and tracheoles into cells
opposite for CO2

Question 6

describe how respiratory gases are transported by mass transport

Answer 6

contraction of muscles squeezes trachea
enabling mass movement of air in and out of insect

Question 7

describe how respiratory gases are transported by osmosis

Answer 7

ends of tracheoles are filled with water
muscle cells around tracheoles respire anaerobically producing soluble lactate
which lowers water potential of muscle cells
so water moves into cells from tracheoles by osmosis

Question 8

what are spiracles

Answer 8

tiny pores on insects where gases enter and leave trachea

Question 9

how do spiracles work

Answer 9

they are opened and closed by a valve
when they are open, water vapour can evaporate from insect

Question 10

limitation of the tracheal system

Answer 10

diffusion pathway is short and limits the size the insect can attain