Answer:
1. Violin 1: Plays the melody (theme) at the beginning of the movement, with accompaniment by the other instruments.
2. Violin 2: Accompanies the melody played by Violin 1 at the beginning of the movement.
3. Viola: Accompanies the melody played by Violin 1 at the beginning of the movement.
4. Cello: Accompanies the melody played by Violin 1 at the beginning of the movement.
5. All instruments: Play variations on the "Emperor's Hymn" theme throughout the movement.