4 2
This question is about gaseous exchange. A frog can take in oxygen through its skin and lungs.
lungs
(a) Look at the graph. It shows the amount of oxygen taken up by a frog at different times of the year. 120 100 oxygen uptake in relative units
lung
80 60 outer surface
40 20 0
Jan Feb Mar Apr May Jun July Aug Sept Oct Nov Dec month of the year
Describe two patterns shown in the graph. ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... .............................................................................................................................................. [2] (b) Frogs can only live in certain habitats. Their skin is adapted to take in oxygen from its surroundings. Explain why this restricts where they can live. ................................................................................................................................................... ................................................................................................................................................... .............................................................................................................................................. [2] Š OCR 2014