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

Megaspore mother cell Melosis $\longrightarrow$ Megaspores $\stackrel{\text { Mitosis }}{\longrightarrow}$ embryo sac Meiosis $\longrightarrow$ egg.

Diploid megasporo mother cell $(2 \mathrm{n})$ divides meiotically and produces four haploid mega spores. In activated megaspores it divides metotically for 3 times and a embryo sac having eight haploid nuclei is prepared. While other three megaspores are destroyed.

Embryo sac is a structure having $7$ celled and $8$ nucleate. In which three nuclei, are located at the end of micropyle; three at the end of hilum and one cell is located in the middle.

Cells near to micropyle combinely known as egg apparatus that contains two synergid cells and one egg cell.

Three cells located towards hillum are antipodal cells and central cell, possese polar nuclei till fertilisation does not take place.