List the changes observed in an angiosperm flower subsequent to pollination and fertilisation.

(N/A) Following pollination and fertilisation in an angiosperm flower,the following post-fertilisation changes occur:
$1$. The sepals,petals,and stamens usually wither and fall off,although the sepals may sometimes persist.
$2$. The zygote develops into the embryo.
$3$. The primary endosperm nucleus $(PEN)$ develops into the endosperm,which provides nourishment to the developing embryo.
$4$. The ovule matures into the seed.
$5$. The ovary matures into the fruit.
$6$. The ovary wall develops into the pericarp (fruit wall).