The chemical carcinogens present in tobacco smoke is the major cause of _________.
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → Lung Cancer
Tobacco smoke contains chemical carcinogens, substances that turn normal cells into cancer cells.
Option (1) AIDS — Incorrect. AIDS is caused by HIV, a virus that attacks helper T-cells.
Option (2) Lung Cancer — Correct. Smoking is linked with cancers of the lung, urinary bladder and throat.
Option (3) Allergy — Incorrect. An allergy is an exaggerated immune response to allergens such as dust or pollen, mediated by IgE.
Option (4) Pneumonia — Incorrect. Pneumonia is a lung infection caused by bacteria such as Streptococcus pneumoniae, not by carcinogens.
NCERT Extract:
Drugs and Alcohol Abuse – “Smoking also paves the way to hard drugs. Tobacco has been used by human beings for more than 400 years. It is smoked, chewed or used as a snuff. Tobacco contains a large number of chemical substances including nicotine, an alkaloid. Nicotine stimulates adrenal gland to release adrenaline and nor-adrenaline into blood circulation, both of which raise blood pressure and increase heart rate. Smoking is associated with increased incidence of cancers of lung, urinary bladder and throat, bronchitis, emphysema, coronary heart disease, gastric ulcer, etc. Tobacco chewing is associated with increased risk of cancer of the oral cavity.”