Chapter Summary
Sexual Reproduction in Flowering Plants involves the production of male and female gametes, pollination, fertilization, and the development of seeds and fruits. Key processes include microsporogenesis, megasporogenesis, double fertilization, and post-fertilization changes.
50 Questions and Answers
It is the process of formation of microspores (pollen grains) from microspore mother cells by meiosis.
It is the formation of megaspore from megaspore mother cell through meiosis in the ovule.
Double fertilization is a unique feature of angiosperms where one male gamete fuses with the egg (syngamy) and the other fuses with the two polar nuclei (triple fusion).
Synergids are two specialized cells present in the embryo sac that help in guiding the pollen tube for fertilization.
Endosperm provides nourishment to the developing embryo during seed formation.
Pollination is the transfer of pollen grains from anther to the stigma of a flower.
Self-pollination occurs within the same flower or between flowers of the same plant, while cross-pollination occurs between flowers of different plants of the same species.
Agents of pollination include wind, water, insects, birds, and animals.
Autogamy is a type of self-pollination where pollen from the anther is transferred to the stigma of the same flower.
Geitonogamy is the transfer of pollen grains from the anther of one flower to the stigma of another flower on the same plant.
Xenogamy is cross-pollination where pollen grains are transferred from one plant to another of the same species.
Emasculation is the removal of anthers from a bisexual flower before they release pollen, usually done in artificial hybridization.
Bagging is covering the emasculated flower with a bag to prevent contamination from unwanted pollen.
It is the fusion of a male gamete with two polar nuclei to form a triploid primary endosperm nucleus.
Apomixis is a form of asexual reproduction where seeds are formed without fertilization.
Parthenocarpy is the development of fruits without fertilization, resulting in seedless fruits.
Maize is an example of a plant that shows wind pollination.
It refers to the recognition and acceptance or rejection of pollen by the stigma.
Self-incompatibility is the inability of a plant to produce fertile seeds after self-pollination.
The tapetum provides nourishment and contributes to the formation of pollen wall.
It is the process by which anthers release pollen grains after maturity.
Sporopollenin is a highly resistant organic material present in the exine layer of pollen grains.
Antipodal cells usually degenerate after fertilization, though they may provide nourishment in some plants.
The end of the ovule opposite to the micropyle is called the chalazal end.
Micropyle is the small opening in the ovule through which the pollen tube enters during fertilization.
Hilum is the scar on the seed coat marking the point of attachment to the fruit wall.
Perisperm is the persistent nucellus in the seed which provides nourishment.
Polyembryony is the occurrence of more than one embryo in a single seed.
Citrus is an example of a plant showing polyembryony.
Pollen viability refers to the ability of pollen grains to fertilize a female gamete.
It varies from a few minutes (in rice and wheat) to months (in some leguminous plants).
Integuments protect the developing embryo sac and later form the seed coat.
Zygote is the diploid cell formed after fusion of male and female gametes.
Endosperm is triploid (3n).
Cotyledons store food for the developing seedling.
Fruit is the ripened ovary formed after fertilization.
Parthenocarpic fruits are seedless fruits developed without fertilization.
Seed dormancy is a condition where viable seeds fail to germinate even under favorable conditions.
Vivipary is the germination of seeds while still attached to the parent plant, e.g., mangroves.
Cleistogamy is a condition where flowers never open and always undergo self-pollination.
Protandry is the condition where anthers mature before the stigma in a bisexual flower.
Protogyny is the condition where stigma matures before the anthers in a bisexual flower.
Heterostyly is the presence of different lengths of styles and stamens in flowers to promote cross-pollination.
Dichogamy is the condition where anthers and stigma of a flower mature at different times to prevent self-pollination.
Pollen tube is a tubular structure produced by pollen grain to deliver male gametes to the embryo sac.
Syngamy is the fusion of a male gamete with the egg cell to form a zygote.
Pericarp is the wall of the fruit formed from the ovary wall after fertilization.
Nucellus is the central part of the ovule that provides nourishment to the developing embryo sac.
Endothelium is a specialized nutritive layer surrounding the embryo sac in some plants.
Scutellum is the single cotyledon found in monocot seeds like maize.