How can i label a graph with negative values

For the y axis the units are = ug min-1 X 10^-3 (biology graph question)
The range of values are = 1.17 X 10^-3 to 4.0 X 10^-3
I'm not sure whether to go in ascending or descending order :/

Should 1.17 or 4.0 be the starting value and do I need to start at 0? If I don't, do I need to put that squiggly line thing to indicate its a broken axis(?)

for reference it is question 5.2:
https://pmt.physicsandmathstutor.com/download/Biology/A-level/Past-Papers/AQA/AS-Paper-1/June%202016%20QP%20-%20Paper%201%20AQA%20Biology%20AS-level.pdf

Bear in mind this is the maths forum, rather than biology which may have its own requirements - though I doubt they'd differ.

Given the range of values, I'd start at 0 on the y-axis.

Your x-axis is presumably the day, and as such will determine which y-value goes where - day would start from 0.

Don't forget to label the axes.

Edit: I don't see any "negative values".