The Jeopardy song IS TOO just “Twinkle Twinkle” with a funky beat. Try singing “Twinkle Twinkle” to the Jeopardy tune, and you’ll see that it fits.
It is totally not. The phrasing is the same but the notes are totally different.
Also, “You are my sunshine” and “This land is your land” use the same tune. As each other, I mean.
Also not true. Again, same phrasing, different notes.