2. Biology of Tumors

Question 1

Normal vs cancer cell growth

Answer 1

Normal cells: Renew cyclically under strict control mechanisms.
Cancer cells: Lose control due to mutations

Question 2

Cancer mutations lead to:

Answer 2

• Uncontrolled proliferation
• Resistance to apoptosis
• Metastasis

Question 3

External causes of mutations

Answer 3

Radiation (UV, X-rays), chemicals (tobacco, asbestos), viruses (HPV, EBV).

Question 4

Internal causes of mutations:

Answer 4

Genetic disorders
Hormonal imbalances (e.g., estrogen in breast cancer).