A-Level Biology OCR A H420
Paper 1 - Jun 2018 H420/01
Time allowed: 2 h 15 min.
The total mark for this paper is 100.
The marks for each question are shown in brackets [ ].
1.
Which of the following statements, A to D, correctly explains a feature of an efficient gaseous exchange surface?
A - The layers are thin for a short diffusion distance.
B - There is a good blood supply, so the system reaches equilibrium quickly.
C - There is an increased surface area to reduce surface area to volume ratio.
D - Ventilation takes place to reduce concentration gradient of dissolved gases.
[1]
A
END OF QUESTION PAPER
[1]