Biology · Oct / Nov 2022 · Paper 41 · Question 6

name of the letter on function

structure

Fig. 6.1 traps particles (before they enter the

hairs in the

airway) / mechanical barrier to

A nose

pathogens / AW

prevents collapse of the airway

cartilage

J / B external

contracts to decrease the pressure in

intercostal

F the thorax

muscles

contracts to, reduce the pressure

diaphragm

C / increase the volume, in the thorax

protects the lungs from mechanical

rib(cage)

E damage

trachea

J contain cilia to move mucus out of

/ bronchi

/ B the airway

/ bronchiole

/ G site of gas exchange / AW

alveoli

H ;;;;;;;

any three from:

thin / one cell thick ;

large surface area ;

(which) reduces diffusion distance / AW ;

good blood supply ;

AVP ;

any three from:

less oxygen and more carbon dioxide in expired air (than inspired air) ;

(as) oxygen is required for aerobic respiration ;

carbon dioxide is released by respiration ;

water vapour increases (as it is released by respiration) ; AVP ;

detected:

either

(carbon dioxide is) in the blood

or

by the brain ;

response:

either

increases, rate / depth, of breathing

or

increases heart rate / AW ;

limewater / hydrogencarbonate indicator (solution) / AVP ;