unit 3, gas exchange in insects

Question 1

what do insects have instead of lungs for gas exchange

Answer 1

•instead of lungs they have air filled sacs called tracheae

Question 2

why can insects not be big

Answer 2

their respiratory system wouldn’t be able to handle the demand

Question 3

what happens in ventilation

Answer 3

pumping abdomen draws air in and out

Question 4

what do the spiracles do

Answer 4

•limit water loss
•they have hairs to trap humid air to reduce concentration gradient
•air sacs along tracheae to store oxygen
•series of tubes

Question 5

carbon dioxide release process for insect

Answer 5

1) goes through trachioles from cells down a concentration gradient
2)moves through tracheae
3) moves out of the tracheae to the spiracles
4) out of spiracles

Question 6

why do the tracheae have strengthened rings

Answer 6

to stop them from collapsing

Question 7

why do the tracheae branch off into tracheoles

Answer 7

for a large surface area and for gases to be exchanged efficiently

Question 8

why is gas exchanged across whole organism

Answer 8

due to lots of branches

Question 9

what’s in conflict due to the thin permeable membrane

Answer 9

between water loss as it’s so thing and gas exchange

Question 10

what’s a modification of the spiracles

Answer 10

having hair to trap humid air to make low concentration gradient

Question 11

oxygen going in process in insects

Answer 11

1) air moves through on surface (spiracles)
2) oxygen travels down tracheae down a concentration gradient
3) goes through trachioles
4) to the cells

Question 12

Why does fluid in the ends of trachea where it joins tissue increase diffusion?

Answer 12

• gas exchange from air to liquid occurs in the tracheole which allows gases to diffuse to tissues faster
• fluid can be withdrawn into the body fluid to increase surface area of tracheole exposed to air

Question 13

why do insects need a gas exhange system?

Answer 13

Insects have an exoskeleton made of hard fibrous material for protection and a lipid layer to prevent water loss.
Insects do not have lungs, and instead have a tracheal system.

Question 14

methods of moving gases in tracheole

Answer 14

• diffusion, due to when respiration takes place co2 is produced, creating a concentration gradient for 0xygen
  -contraction and relaxtion of abdominal muscles
  -osmosis, when anaerobic respiration takes place, this produces lactic acid which lowers the water potential in the cell cuasing it to gain water by osmosis, this causes air to be drwn up trahceole