I would say in strictest classical terms, definitely not. However, rap DOES require a very basic understanding of pop theory, for example, scales have seven notes, 4/4 timings and tempos.
Honestly, that's about all they need, they do not require knowledge of classical theory such as how scales are formed from tetrachords and such.
Why such a question anyway? Especially since we all know jokes like "music is like candy, you gotta throw away all the rappers" are abound.