Explanation:
In angiosperms, the ovule contains an embryo sac (female gametophyte) which is formed from a megaspore. The mature embryo sac has three cells called antipodals at the chalazal end and three cells at micropylar and constituting the egg apparatus. Each of these cells consists nuclei. The egg apparatus consists of two synegids and one egg cell. There is large central cell Present which consists of two polar nuclei. Hence, embryo sac has 7 cells and eight nuclei.
The poolen tube ultimatly enters an ovule throught the micropyle and penetrates one of the sterile cells on either side of the egg.
