why is the advantageous for a cell to grow only to a certain size and then divide into two smaller cells?

if the size of the cell increases without dividing the amount of nutrients entering the cell will be less compared to the size of the cell ... A cell gets all its nutreints by diffusion/active transport (phagocytosis-pinocytosis)/lysososomes ..(in other words all through its cell wall) .. As you might know the bigger the volume the smaller the surface area .. therefore a small cell will have larger cell wall compared to its size and the bigger it gets, the smaller its surface area becomes and its cell wall (read on surface area to volume ratio) ...

Also a cell that does not divide either becomes cancerous cell (malegnant) (coz of the lack of nutreints-and the age of the cell itself which cannot carry its normal function anymore) or enters a phase known as a the Go phase (i.e apoptosis) <-- like dying but still alife.

The only way a cell can pass its genetic make up to another generation of cells is through division.. the two smaller cells it produces have a reason to be small .. but this is all 'advanced molecular cell biology' which i dont think ull need now .. for example when you get a sore throat this is due to a virus or bacteria infecting ur cell linning of your throat .. the virus or bacteria can only infect the adult cells .. the mechanism by which the cell protects itself is that it divides into two smaller cells <--- viruses cannot attack smaller cells and this gives time for macrophages to destroy the viruses!!!

My guess would be because once a cell gets to be too large, it takes more time for it to receive the nutrients it needs. So it divides to increase the speed of the process and become more efficient.

But I'm probably wrong, I'm just a high school student. =]