sexual reproduction in flowering plants full chapter notes
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Answer:
Flower is a modified stem which functions as a reproductive organ and produces ova and/or pollen. A typical angiospermic flower consists of four whorls of floral appendages attached on the receptacle: calyx, corolla, androecium (male reproductive organ consisting of stamens) and gynoecium (composed of ovary, style and stigma) .
Sexual Reproduction in Flowering Plants Class 12 Notes Biology
Pre-fertilisation: Structures and Events
• Several structural and hormonal changes lead to formation and development of the floral primordium. Inflorescence is formed that bears floral buds and then flower.
• In flowers, male (androecium) and female (gynoecium) differentiate and develops in which male and female gametes are produced.
Stamen, Microsporangium and Pollen Grain :
• Stamen consists of long and slender stalk called filament and generally bilobed anthers. Each lobe contains two theca (dithecious).
• The anther is four-sided structure consisting of four microsporangia, two in each lobes.
• Microsporangia develop further and become pollen sacs which contain pollen grains