AQA-A-LEVEL-BIOLOGY
Biology
All content from AS and A level covered
Sample Data
| Front |
 (2 marks) |
| Back |
 |
| Front | how is the structure of the arteries related to its function |
| Back | .thick muscle layer compared to veins -> can constrict and dilate to control volume of blood passing through them.thick elastic layer compared to veins -> stretching and recoiling helps to maintain high pressure .thick wall -> prevents vessel from bursting under pressure |
| Front | how does the binding of haemoglobin with oxygen affect oxygen-haemoglobin binding |
| Back | .first oxygen binds -> changes tertiary structure haemoglobin.uncovers other binding sites —> easier for second and third molecules to bind ( positive cooperativity ).slightly harder for 4th oxygen molecule to bind -> low chance of finding a binding site |