Answer
The large cell will not have enough DNA, and the surface area to volume ratio will be unideal for diffusion across the membrane.
Work Step by Step
When a cell grows, its size increases but its DNA molecule does not. Thus, there is not enough DNA to process all the required functions for a cell that is too large.
Additionally, when a cell gets too large, its volume overwhelms its surface area. Thus, not enough diffusion across the membrane occurs, and the cell will not have enough nutrients and minerals to survive.
