a) Smoking affect circulatory system in following ways: 1. The carbon mono oxide present in tobacco smoke lessens the oxygen carrying capacity of haemoglobin. 2. Thickens the blood by producing more platelets. Correct Answer Smoking affect circulatory system in following ways: 1. The carbon mono oxide present in tobacco smoke lessens the oxygen carrying capacity of haemoglobin. 2. Thickens the blood by producing more platelets.