Formation of Female Gamete

Embryo Sac Development

Cells of Carpel Sac are 2n

• Cell in Ovule divide by Meiosis and it becomes the embryo sac or Megaspore

Meiosis

• 4 Haploid Cells are made

• 3 die and 1 survive

Cell Division• Mitosis

• Mitosis

• Mitosis

8 Nuclei

• The Embryo Sac swells and now contains 8 nuclei

• This is also called the Megaspore

Nuclei in Embryo Sac

• Polar Nuclei and Egg Cell survive

• Other Nuclei die

Egg Cell

2 Polar Nuclei

Double Fertilisation• 1 male gamete from the pollen

grain fuses with the egg nucleus to form the embryo plant• Polar Nuclei join with the 2nd Cell

form pollen grain to form Endosperm

Fertilised Ovule = SeedIntegument = Testa

No water needed

Adaptation to life on land