This free quiz has all 15 multiple choice questions from Section A of the OCR A Level Biology A Biological Processes paper (H420/01), June 2024. It marks itself, so you get your score as soon as you finish.
What the multiple choice section covers
Lipid structure, macromolecules and polymers (2.1.2)
Phospholipids and plasma membrane structure (2.1.2, 2.1.5)
Hormone action through cell surface receptors (5.1.5)
Tissue fluid, lymph and the mammalian heart (3.1.2)
Ventilation and gas exchange in insects and fish (3.1.1)
Liver structure, liver histology and urea production (5.1.2)
Limiting factors and light intensity effects in photosynthesis (5.2.1)
Energy values of respiratory substrates (5.2.2)
How to use it
Section A is 15 of the 100 marks on a 2 hour 15 minute paper, so about 20 minutes is a fair share. Some questions ask which option is not correct, so read every stem carefully, and examiners stressed being secure with precise terminology such as polar, saturated, intrinsic and extrinsic. Paper 1 tests modules 1, 2, 3 and 5, so expect Year 12 and Year 13 content side by side.
Where students lost marks on this paper (from the OCR examiners' report and mark scheme)
These points cover the whole paper, not just the multiple choice section. Each is followed by wording that gained marks.
Misreading respiratory quotient data: Many candidates thought a rising RQ around 0.8 showed protein use rather than increasing use of carbohydrate, and only the strongest noticed the RQ never reached 1.
✔ Gains credit: RQ of carbohydrate is 1 and of fat about 0.7, so fat is mainly used at rest, more carbohydrate is used as intensity rises, and some fat is still used even at maximum effort.
Rate without a tangent: Some candidates simply read the value off the curve at the stated time, or divided the x and y readings, instead of finding the gradient.
✔ Gains credit: drawing a straight tangent touching the curve at the stated time, dividing the change in y by the change in x from that tangent, and giving units such as µg s-1 to no more than three significant figures.
Explaining heart rate control: Less successful candidates used only one graph, describing either breathing rate or heart rate, and missed the homeostatic explanation.
✔ Gains credit: both breathing and heart rate increase as oxygen saturation falls and carbon dioxide lowers blood pH, detected by chemoreceptors, with the cardiovascular centre sending impulses (not 'signals') along the sympathetic nerve so the SAN generates waves of excitation faster.
Describing instead of explaining: Many candidates described the shape of the beetroot pigment graph instead of explaining it.
✔ Gains credit: ethanol disrupts the phospholipid bilayer and increases membrane permeability so more pigment leaks out, and the curve levels off once all the pigment has been released.
Wrong glycosidic bond in maltose: The mark scheme did not accept beta or 1,6 for the bond between the glucose monomers in maltose.
✔ Gains credit: an alpha 1,4 glycosidic bond, from carbon 1 of one glucose to carbon 4 of the next.
Non-comparative tissue fluid answers: The mark scheme did not credit statements that gave pressures without comparing them at each end of the capillary.
✔ Gains credit: hydrostatic pressure is higher than oncotic pressure at the arteriole end so fluid moves out, and lower than oncotic pressure at the venule end so fluid moves back in.
Defining tropism loosely: The mark scheme did not accept 'growth' without a sense of direction, and did not accept the spelling 'trophism'.
✔ Gains credit: directional growth in response to a stimulus, towards or away from it, with examples such as phototropism or geotropism.
Keep practising
Try the multiple choice sections of the June 2024 AS paper and June 2024 Biological Diversity paper, or practise by topic with the Transport in Animals, Plant and Animal Responses, Photosynthesis, Enzymes quizzes. You can also browse all our OCR A Level Biology quizzes. Our OCR A masterclasses (Year 12 on Wednesdays at 5.15pm, Year 13 on Tuesdays at 6.30pm) work through real exam questions on one topic each week.
Practising recall is so important for retention and learning. Try this quiz without books first !