What is it called when the defensive player catches a pass intended for an offensive receiver?

What is it called when the Quarterback has his flag pulled by the defense behind the line of scrimmage?

What is it called when the ball is dropped after being in possession?

What is it called when you enter the end zone with possession of the ball?

How many points is a touchdown worth?

How many "downs" to advance the ball to the 1st down marker?

What is the imaginary line where each play starts called?