Q4. Give two ways in which malignant tumors harm the body, besides spreading.
Their cells grow very rapidly, invading and damaging the surrounding normal tissues, and they starve the normal cells by competing for vital nutrients (NCERT page 141).
Q5. What are cellular oncogenes, and when can they cause cancer?
Genes, also called proto oncogenes (c-onc), identified in normal cells; when activated under certain conditions they could lead to oncogenic transformation of the cells (NCERT page 141).
Q6. How is a biopsy examined?
A piece of the suspected tissue is cut into thin sections, stained and examined under a microscope by a pathologist (histopathological studies) (NCERT page 141).
Q7. Why are patients given α-interferon?
Tumor cells can avoid detection and destruction by the immune system; α-interferon, a biological response modifier, activates the patient’s immune system and helps destroy the tumor (NCERT page 142).
Q8. Name two side effects of chemotherapeutic drugs that NCERT mentions.
Hair loss and anemia (NCERT page 142).