Question

Why is apple called a false fruit?

Answer 1

Apple is not a true fruit because it's pulp contains not only ovary as in a true fruit but thalamus as well..

Answer 2

When other accessory floral parts contribute to the formation of fruit, then such fruits are called as false fruits or pseudocarp.

In apple, the thalamus or receptacle grows around the pericarp to produce the fleshy edible part.