Question 25
Which one best explains how cigarettes cause lung cancers?
1. Smoking cigarettes transfers virus to the lungs that cause cancer
b. Cigarette smoking deposits tar in lungs which decreases lung capacity and therefore
c. Cigarette smoke contains carbon monoxide that accumulates in lungs to causes cancer
d. Cigarette smoke causes cells to mutate which increases their risk of becoming cancerous
Question 26
Answers
Answer:
Explanation:
Doctors believe smoking causes lung cancer by damaging the cells that line the lungs. When you inhale cigarette smoke, which is full of cancer-causing substances (carcinogens), changes in the lung tissue begin almost immediately. At first your body may be able to repair this damage.
The tar in cigarette smoke builds up inside the lungs as it is inhaled. 4 Over time, a healthy pink lung tissue turns grey and eventually becomes black as more tar accumulates. The primary effect is that the tar paralyzes and can eventually kill cilia in the lungs.
Ethylene oxide is associated with malignancies of the lymphatic and hematopoietic systems in both humans and laboratory animals (IARC 1994). Diverse metals such as the human carcinogen cadmium are also present in cigarette smoke, as is the radioisotope polonium 210, which is carcinogenic to humans.
It's that perpetuation of growth that can eventually become cancer. Additionally, smoking can impact the DNA itself, can damage the DNA, and through accumulating mutations over time, those DNA mutations lead to cell growth and then cancer and cancer metastasis.