[Campbell Biology P.297] According to Figures 12.18 and 12.19 and the accompanying text, whi... | Practice Question

According to Figures 12.18 and 12.19 and the accompanying text, which of the following statements accurately describes a difference between normal mammalian cells and cancer cells in culture?

  • A: Normal mammalian cells typically divide indefinitely if provided with a continual supply of nutrients, while cancer cells exhibit density-dependent inhibition.
  • B: Cancer cells exhibit anchorage dependence, meaning they must attach to a substratum to divide, whereas normal cells can divide in suspension.
  • C: Normal mammalian cells exhibit density-dependent inhibition, stopping division when a single layer is formed, while cancer cells typically continue to divide, forming clumps.
  • D: Both normal and cancer cells require platelet-derived growth factor (PDGF) to proliferate in culture.

Explanation

Figure 12.19 illustrates that normal mammalian cells stop dividing once they form a complete single layer density-dependent inhibition . In contrast, cancer cells continue to divide well beyond a single layer, forming clumps of overlapping cells, indicating they do not exhibit density-dependent inhibition. The text also confirms this difference and states that cancer cells do not heed normal signals.