Comprehensive Study of Sexual Reproduction and Seed Formation in Flowering Plants

The chapter begins with the structure of a typical flower, describing parts like androecium (stamens) and gynoecium (carpels/pistil) as the male and female reproductive organs. It explains microsporogenesis and megasporogenesis, showing how pollen grains (male gametophyte) form inside anthers and how the embryo sac (female gametophyte) develops inside the ovule. Pollination and pollen–pistil interaction Students learn about pollination and its types: self-pollination (autogamy, geitonogamy) and cross-pollination (xenogamy). The chapter also describes pollinating agents such as wind, water and animals, and explains how compatible pollen germinates on the stigma, grows a pollen tube through the style, and reaches the embryo sac. Fertilisation and seed/fruit formation A key concept is double fertilisation in angiosperms, where one male gamete fuses with the egg to form the zygote and the other fuses with the central cell to form endosperm. The chapter then discusses post-fertilisation changes including development of embryo, endosperm, seed and fruit, along with features of monocot and dicot seeds and terms like albuminous, exalbuminous seeds and perisperm. Special phenomena in reproduction In the end, the chapter introduces apomixis (seed formation without fertilisation) and polyembryony (formation of more than one embryo in a seed). These phenomena are linked to plant breeding and hybrid seed production, showing the practical importance of understanding sexual reproduction in flowering plants for crop improvement and agriculture.