Don't present your data like this, for goodness' sake:
We can't see the labels for the axes and the gate frequency is obscuring population of interest. Don't bother trying the fix this in PowerPoint, either... you'll waste a bunch of time remaking the axis labels, and - in this case - trying to find the Symbol font in the menu (arrrrrrgh!!!):
Instead, use this two-second tip to start with presentation ready graphics straight out of FlowJo (v9, for Mac). Go to the FlowJo menu, select Preferences, then the Text tab, and make your axis labels really big:
You can also go the "Gates" tab, make your gates thicker (Gate Display: Line Weight), and move your gate frequencies out of the way (Position for Annotation; Top Left often works).
And the result propagates to every new layout graphic you make. Now, you can cut and paste, right into your powerpoint slide, without any more manipulation:
Saves time, and it's a permanent fix, so you only have to do this once (you can undo it, of course). It let's everyone see the raw data (i.e., the recorded channel names, all events in the distribution).
Two seconds to better presentation graphics. Make your students do it before lab meeting!