BIOLOGY
9
DOUBLE FERTILISATION IN ANGIOSPERMS
Subject :
Class :
Lesson :
Capsule No :
Amaryllis
Chinese hibiscus
Calla Lily
Costus (Yellow Trumpet)
Parts of pistil
Parts of stamen
One bee colony can pollinate 300 million flowers every day!
Bees pollinate 80-90% of the world’s nutrition supply!
One bee can carry nectar and pollen which is 80% of its body weight!
Fun facts about Bee pollinators!
Structure of Pollen Grain
Protective layers:
Nuclei:
Two Sperm nuclei
Structure of Ovule
Protective layers:
Nutritive Tissue:
Embryo Sac:
What is Fertilisation?
Fusion of male and female gamete to form a zygote is called fertilisation.
Process of Double Fertilisation
Triple Fusion
Zygote
Endosperm nucleus
Sperm nucleus
Egg nucleus
Sperm nucleus
Polar nucleus
Polar nucleus
Embryo
Endosperm
Syngamy
FACT CHECK!
Double fertilisation was discovered by
C. Nawaschin in 1898
Fruit and Seed Formation
Part | What it becomes |
Ovary | Fruit |
Ovary wall | Pericarp |
ovule | Seed |
Placenta | Stalk of a seed |
Integuments | Seed coat |
Polar nuclei | Endosperm |
Egg cell + synergids | Embryo |
Antipodal cells | Disorganised |
Quick Quiz!
Q: How many nuclei are taking part in double fertilization?
Ans: 5
Crossword Time!
THANK YOU!