In a healthy eukaryotic cell, the rate of DNA repair is typically equal to the rate of DNA mutation. When the rate of repair lags behind the rate of mutation, what is a possible fate of the cell?

The cell may be converted to malignant tumor cell.

Explanation:

Due to failure of lag in the normal repair process, there will be formation of irreparable mutated DNA which may include double-strand breaks and cross-linkages in DNA. Due to this the normal functioning of the cell will be disturbed and there may be formation of malignant tumor or cancer. The normal repair process in necessary for any cell to compensate the mutations in DNA that even occur during division or replication.