Production of seed without fertilization is called

In $Taraxacum$,the unreduced embryo sac is derived from . . . . . . .

Statement-$X$: Apomixis is seen in a few flowering plants such as some species of $Asteraceae$ and grasses.
Statement-$Y$: Apomixis is a form of asexual reproduction that mimics sexual reproduction.
Statement-$Z$: In some species of apomictic seeds,the diploid egg cell is formed without reduction division.

Populations whose members reproduce asexually are termed as:

In citrus,adventive embryony arises from which of the following?

Can an unfertilised,apomictic embryo sac give rise to a diploid embryo? If yes,then how?