Aggregate fruits are formed from polycarpellary apocarpous ovary. Each carpel develops into a fruitlet and all fruitlets together form an aggregate fruit. An etaerio of berries (aggregate fruit) is found in Annona squamosal (custard apple), Polyalthia etc.
The fruit in Ananas and Artocarpus is sorosis (multiple fruit). This type of fruit develops from entire inflorescence.
The fruit of Pyrus malus is pome, which develops from syncarpous inferior ovary, which is surrounded by fleshy thalamus.