Question

What is embryo sac¿ where it is present

Answer 1

Answer:

The enbryo sac is an oval structure present in the ovule of flowering plants. An embryo sac is when the haploid megaspore nucleus divides. At the event of fertilization one male nucleus and egg nucleus combine for the formation of zygote leading to the development of the enbryo

Answer 2

Embryo sac is a  thin walled sac structure of seed plant. it is present in ovule.

Explanation:

• Embryo sac is called as female gametophyte.
• a single diploid mother cell undergo meiosis to give rise haploid megaspore tetrad. out of these three disintegrates and one sustain that developed into embryo sac later
• it is a tiny thin walled sac structure and contains 8 haploid nuclei. among them one is egg cell(n).
• within embryo sac endosperm development take place. two polar nuclei among 8 nuclei migrate toward the center and fused to generate a single cell(2n). when it is fertilized by sperm cell(n) it give rise endosperm(3n).  
• at the event of fertilization egg nucleus fertilized by male nucleus to produce zygote that leading to the development of embryo.
• embryo sac developed within ovule of flowering plant.