How many movements are there in Berlioz’s Symphonie fantasti…

How many movements are there in Berlioz’s Symphonie fantastique [answer1]? It features an original melody in all of the movements that represents the woman with whom Berlioz was obsessed. He called this melody a/an: [answer2].  It also features a melody in the final movement that was a well-known Gregorian chant that was used in funeral masses. Berlioz used it to create darkness and dread. What was the chant? [answer3]