The surface area becomes 4 times greater if the cell is double in length.
Cell Double In Length The Surface Area Becomes_______times As Large.
Your question does not make sense in English. I will make some assumptions (which may be right or wrong) and answer my own question. If I ask, "I have an area with length and width. I double the length. The resulting is how many times as large?" The answer is TWO times as large.