Draw the diagram of a mature embryo sac and show its $8-$ nucleate,$7-$ celled nature. Show the following parts: antipodals,synergids,egg,central cell,polar nuclei.

(N/A) mature embryo sac is $8-$ nucleate and $7-$ celled.
$1$. $3$ cells are grouped at the chalazal end and are called antipodals.
$2$. $3$ cells are grouped at the micropylar end,which constitute the egg apparatus (one egg cell and two synergids).
$3$. The large central cell contains two polar nuclei,which eventually fuse to form a diploid secondary nucleus.
Thus,the arrangement is $3+2+3$ nuclei,resulting in $7$ cells ($3$ antipodals + $1$ central cell + $2$ synergids + $1$ egg cell).