If several musicians were to play the same melody in unison, the texture would be

The texture would be heterophony, if the musicians have used the same melody in unison. This type of texture has a line of which it only has a single melody with its simultaneous variations. This type of texture could be incorporated with two or more performers.

the mass and the sacrifice are similar because jesus christ is the victim and priest in both. the mass is different from the sacrifice in that jesus died for the remission of sins and cannot be  sacrificed again during the mass.