$X$ – $MMC$ is a large cell containing dense cytoplasm and a prominent nucleus

$Y$ – Method of embryo sac formation from a single megaspore is termed monosporic

What does the filiform apparatus do at the entrance into ovule?

Indicate the stages where meiosis and mitosis occur $(1,\, 2$ or $3)$ in the flow  chart.Megaspore mother cell $\xrightarrow{1}$ Megaspores $\xrightarrow{2}$ Embryo sac $\xrightarrow{3}$ Egg

With a neat, labelled diagram, describe the parts of a mature angiosperm embryo sac. Mention the role of synergids.

Two nuclei with one cell are found in