Final answer:
In a solid tumour, apoptosis occurs less frequently than in cells of normal tissue, enabling cancer cells to proliferate despite damage or mutations.
Step-by-step explanation:
Compared to cells of a normal tissue, apoptosis occurs less frequently in cells within a solid tumour. Apoptosis, also known as programmed cell death, is a natural process by which cells that are damaged or no longer needed are systematically destroyed. In contrast, tumor cells tend to evade this programmed cell death, allowing them to survive and proliferate even when they carry mutations or suffer from damage that would normally trigger apoptosis. This evasion of the normal apoptotic pathway is a characteristic property of cancer cells, contributing to the growth and maintenance of tumours.