Apomixis is the development of

What is the formation of a gametophyte directly from a sporophyte called?

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.

Apomixis is seen in

Despite a high level of heterozygosity,the progeny derived from the seed of a cross-pollinated plant was found to be completely uniform. One reason for this may be the phenomenon of:

What is common between vegetative propagation and apomixis?