Mark Scheme
1. Any three: tar damages cilia, mucus build-up, emphysema (alveoli breakdown), lung cancer risk [3]
2. CO binds haemoglobin reducing oxygen transport; nicotine raises heart rate/blood pressure and damages artery lining (any two) [4]
3. Reduced oxygen and damaged arteries increase risk of plaque build-up and blocked coronary arteries [3]