Yes, the number of cells is a linear function (linear and a function).
Step-by-step explanation:
Ok, I may be wrong, but please don't hate me!!!
The number of cells is a function because the number of cells increased by the same amount (times 4 cells) each day.
The number of cells is linear because it increased by the same amount each day and if you placed this function on a graph, you could interpret the values of the number of cells without needing to know the function.
