Answer the following question:

In what way is diffraction from each slit related to the interference pattern in a double - slit experiment?

If we close on of the slits in the case of a double slit experiment, the given apparatus now work for a single slit diffraction experiment. The central maxima and other secondary maxima from each individual single slits interfere to form a central maxima and other maxima for the double slit experiment due to their path differences when these slits work together as a coherent source.