What is embryo sac? Md. Saifur Rahman The female gametophyte of flowering plants, formed by the division of the haploid megaspore nucleus is called embryo sac.You may likeDo I need car insurance?What is car insurance?How could I get cheaper car insurance?What is auto insurance?Why Adulterant food is the barrier to sound health?What are the producers?What are food preservatives?What is food chain?What is tertiary consumer?