So in for say a sentence structure, we have the basic idea phrase, and then it repeats the basic idea again. However, the second repetition basic idea can be either an exact repetition, state and response or modal sequence. What is state and response, and modal sequence?
In music, you can think of phrases like sentences. Musical phrases, like sentences, can have antecedents (call/statement) and consequents (response).
When your instructor is referring to "statement and response", this is what they mean: that the antecedent of the phrase states a declarative gesture. The response is usually contrary to the statement and completes the idea. Take "twinkle twinkle little star":
C C G G A A G = Statement (rising gesture)
F F E E D D C = Response (falling gesture)
A modal sequence is when the music continues a rhythmic idea, usually keeping the same or similar intervals. Modal sequences usually rise or fall. Listen to anything by JS Bach and you'll hear modal sequences everywhere.
In the future, ask your professor or your TA's for help before it gets too late - they will know all of this stuff.