biology paper 1z...confusion

[elixa]

Apart 4m pastpapers wat else shud i do??
CAN some1 explain in detail tidal vol and vital capacity and how to do related past paper que... i cant do any for instance nov 2004 pi q32

 

[imiosa92]

ok tidal volume is basically the amount of air taken in during one breath in and out. So basically when you breathe in and out normally, the volume of air you take in is the tidal vol. Vital capacity is the maximum volume of air taken in during one breath in and out. They usually measure it after inhalation. for ppqz......nov 2004 q32 is the answer is B because from the graph, 4 squares is equal to 1000cm3 and the line shows that only 500cm3 of air is taken in and out. Then there is a huge dip in the graph of about 750cm3 this shows that it's the vital capacity because that is the maximum volume of air breathed in and out.