When the cells from malignant tumours start invading and damaging the normal tissues and reach distant sites through blood, the process is known as:
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → Metastasis
Option (1) Metastasis — Correct. Malignant tumour cells grow rapidly, invade and damage the surrounding normal tissues, and get carried by the blood to distant sites, where they start new tumours. This property is called metastasis, and it is the most feared property of malignant tumours.
NCERT Extract:
Cancer – “… Benign tumors normally remain confined to their original location and do not spread to other parts of the body and cause little damage. The malignant tumors, on the other hand are a mass of proliferating cells called neoplastic or tumor cells. These cells grow very rapidly, invading and damaging the surrounding normal tissues. As these cells actively divide and grow they also starve the normal cells by competing for vital nutrients.”
Cancer – “… Cells sloughed from such tumors reach distant sites through blood, and wherever they get lodged in the body, they start a new tumor there. This property called metastasis is the most feared property of malignant tumors.”