An IRIS project consists of but one questionnaire. It depends on the target group you selected when setting up your scheduler which questions within a particular questionnaire are being accessed.
Take for instance the patient scan. Even though you might have chosen a hospital for your target group, the export will still show you columns regarding whether a child has been in contact with animals, or what the profession of its parents is. Even though these columns might be visible in the export, they do not get filled with data. After all, the questions didn't pop up, so they haven't been answered.