Question

why does the liquid rise in a syringe when its piston is pulled up?

Answer 1

as the pressure in the syringe increase the liquid rises

Answer 2

This is due to the pressure. The liquid pushes up against the hole at the end of the needle, but  there's no air to push back on it, it rushes in.  Then when we  press the plunger back down, it  pushes the liquid back out of the  needle.