Edexcel IGCSE Biology 2.50 Ventilation practical

A graph that makes reference to the following points:

- S scales linear and at least half page

- L straight lines joining points

- A1 axes the correct way around (time on x axis)

- A2 axis labelled 'minutes' and 'breaths per minute' / 'BPM'

- P points plotted correctly within one square

- K indicates (person) P and (person) Q

Allow truncated y axis

Bar graph loses S and L

An explanation that makes reference to three of the following points:

- increases

- oxygen for respiration / aerobic respiration

- muscle

- remove carbon dioxide

An answer that makes reference to four of the following points:

(P may be fitter):

- P has lower breathing rate at rest / Q has higher breathing rate at rest

- P drops more (after exercise) / Q drops less (after exercise)/ P recovers faster (after exercise)/ Q recovers slower (after exercise)

(P may not be fitter):

- both return to normal in same time / both return to normal by 30 minutes

- P breathing rate higher / Q breathing rate lower/ P increase more than Q /Q increase less than P

(Design):

- no data on age / sex / mass / lung size ( 1 )

- may have lung disease / asthma / smoke / drugs / medication / altitude training / nervousness / adrenaline / eq

- no data on exercise intensity /type/amount/hardness/ only one measure of fitness / no information on heart rate

- not repeated / only tested once / eq