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

 

[ammadb]

past papers is the best practice.. repeat them fr better understanding
tidal volume is jo normally ek banda inhale exhale karta hai
while vital capacity is max in and exhaled.
in this que the normal breathing covers 2 squares whch is half of 1dm3 so it will be 0.5dm3 which is 500cm3. the tidal volume.

then count the squares that are covered by max breathing in and out both. they are 15..
so if 4 stand for 1000cm3 .
1 stands for 1000/4
n 15 will for (1000 X 15)/4
which is 3750cm3