Question

What happens to the calyx after fertilization?

Answer 1

The calyx is that part of the flower which is attached to the stem. The petals grow inside the calyx. It has sepals which form a whorl around the flower and protect it.

After fertilization mostly the calyx falls off as its function of protecting the flower or its reproductive parts is over. Otherwise it dries up or becomes shrivelled.

Answer 2

After fertilization,  both the calyx and Corolla fall off as they have no more protective function in flower.