Do not write outside the
box
9
Figure 12 shows exchange surfaces in the lungs.
Figure 12
Oxygen
Cell at lung surface
Blood vessel
Red blood cell
(transports oxygen)
09
1
Explain how one feature shown in Figure 12 increases the rate of oxygen uptake
by the blood.
[2 marks]

Red blood cells - help in transporting oxygen other all the body parts. _ halp to increase the tamprecature in the all the body parts

the element that provides strength to the exoskeletons of clams and oysters is phosphorus.

this is so because calcium carbonate is the main component in the shells. calcium carbonate is strengthened by phosphorus.

explanation:

colors do exist. the color of the sky is actually violet; humans percieve the color of the sky as blue.