exchange in insects

Question 1

where does gas exchange on insects occur

Answer 1

tracheoles

Question 2

large surface area

Answer 2

many tracheoles

Question 3

short diffusion pathway

Answer 3

thin walls
all in contact with cells so can directly provide oxygen

Question 4

maintenance of concentration gradient

Answer 4

low concentration oxygen at tracheoles as it diffuses into cells so oxygen can continuously diffuse into tracheoles
high concentration CO2 at tracheoles from cells

Question 5

water loss

Answer 5

1. can open and close
2. hairs- trap a layer of moisture creating a
   gentle gradient of water potential between
   inside and outside of insect
3. cytoplasm of cells at ends of tracheoles
   contain water- respire anaerobically
   producing lactic acid
   causes water potential to decrease
   water moves out of tracheoles into cells
   pulls oxygen with it

Question 6

mass transport

Answer 6

may need more oxygen so abdominal pumping occurs
squeezes trachea and tracheoles forcing air in and out