Discuss the negative effects of smoking in the human body (6).

Smoking can cause carbon monoxide poisoning, meaning that carbon monoxide is carried in the blood via red blood cells instead of oxygen, leading to fatigue. Smoking can also cause lung cancer, as it contains carcinogenic substances such as tobacco. Smoking can cause respiratory problems such as emphysema, where the alveoli become enlarged, irregular sacs, causing gas exchange to be less efficient. Smoking can also cause heart failure and strokes.