When I was a undergraduate student, I worked in a professor's lab doing research about "A". I helped the senior members to do some work they didn't want to do, like designing a website for their demos, or doing some basic calculations. You don't have to have the background knowledge of A to do that work. Then they added me on two papers, though I was always the last one. Afterwards, during my master study, I conducted real research individually in another field "B". Now I am trying to apply for study in an interdisciplinary field that merges fields A and B.
The problem is I know little about A. I am a afraid that the professors in the admission committee would ask me something about A and I definitely can't answer. And they would think I lied, which I didn't. Should I put the papers on my CV?