It would affect the precision but not the accuracy of your experimental results.
Precision is the repeatability of a measurement.
With this beaker, you know that no matter how careful you are, your volume will be (100 ± 1) mL.
Your maximum precision is 1 part in 100 (1 %).
Accuracy is a measure of how close you are to the actual value.
Accuracy depends partly on you.
If your eye is consistently above or below the graduation mark on the beaker, you will consistently have less or more volume than you think you have.
You will get an inaccurate measurement.
If the beaker contains only 95 mL despite its label, you have no hope of getting an accurate measurement.