Flower has four parts :
Calyx and Corolla - Accessory parts
Androecium and Gynoecium - Reproductive parts.
- Androecium is male part and one unit is stamen.
- Gynoecium is female part and one unit is carpel and has ovules.
- Ovule bears embryo sac.
- Embryo sac is seven celled and has 8 nucleus -
- Reproduction by vegetative and sexual methods.
- In sexual reproduction pollens shed off and reach to stigma of Gynoecium by pollination.
- Pollen germinates to form pollen tube with two male gametes and one tube nucleus.
- One gamete fuses with egg (Syngamy) and other with secondary nucleus to form PEN (primary endosperm nucleus). The whole process is called Double fertilization.
- Zygote forms embryo and PEN forms Endosperm in ovule which changes into seed inside fruit.
- Ovary wall changes into Pericarp (fruit wall).
- Alternation of generation occurs.
