Chapter 10, Problem 5STP

Summary Introduction

Introduction:

Cancer occurs when the normal cell cycle is disrupted and the cell does not respond to control mechanisms. Cancer is uncontrolled growth and division of cells. These unchecked cancer cells can even kill the organism by crowding out normal cells. The changes occur in regulation of cell growth and division of cancer cells due to mutations or changes in certain segments of DNA.

Answer to Problem 5STP

Correct answer :

The correct answer is option A. Exposure to asbestos particles

Explanation of Solution

Explanation/justification for the correct answer:

OptionA. Exposure to asbestos particles- Various environmental factors can affect the occurrence of cancer cells. Substances and agents that are known to cause cancer are called carcinogens. Some common carcinogens are asbestos, cadmium, benzene, tobacco, ultraviolet radiation, X- rays etc. Not all cancers can be prevented but avoiding known carcinogen can help reduce the risk of cancer. Asbestos particles damage lungs and cause lung cancer. Hence, this is the correct option.

Explanation for incorrect answer:

Option B. exposure to fungus spores- Fungal spores cause allergic reactions in many people. So exposure to fungal spores may cause diseases like pneumonia, allergy, asthma, etc. Hence, this is not the correct option.

Option C. exposure to infrared radiation- Exposure to infrared radiation may cause damage to eye lens, retina and cornea. It does not cause cancer of lungs. Hence, this is not the correct option.

Option D. exposure to ultraviolet radiation- Exposure to ultraviolet radiation causes skin cancer and not lung cancer. Hence, this is not the correct option.