Question
What is endosperm of angiosperms ? Describe its types.###What is endosperm ? Explain various types of endosperms.
✓
Answer
Endosperm : As a result of double fertilization and triple fusion, a nutritive tissue formed within the embryo sac by division of endosperm nucleus is called endosperm. It is an essential tissue because it surrounds and nourishes the embryo in the seeds of angiosperms.
Various types of endosperm on the basis fo development :
(1) Nuclear Endosperm : It this type of endosperm nucleus divides to form many free nuclei. There is no will formation at the time of the division. The free nuclei formed, arranges towards the periphery in the cytoplasm. A large central various appears in the embryo sac the wall formation may start after sometimes from periphery towards the centre of the sac. Example: capsella, Euphorbia, Malva, Citrus, etc.
(2) Cellular Endosperm : In this type of endosperm the primary endosperm nucleus divides repeatedly followed by immediate wall formation, Therefore, endosperm becomes cellular from the very beginning Example : Adoxa, Balsam, Datura, etc.
(3) Helobial Endosperm : This type of endospermis of intermediate type between cellular and nuclear type. The first division of endosperm results in the formation two cells lawrger micropylar and smaller chalazal ends. As the subsequent division in the micropylar and begins to increase, the chalazed end starts of degenerate. Finally like that of nuclear endosperm, the multinucleate stage is followed by wall formation. Examples Asophodelus, Eremurus, etc.
Various types of endosperm on the basis fo development :
(1) Nuclear Endosperm : It this type of endosperm nucleus divides to form many free nuclei. There is no will formation at the time of the division. The free nuclei formed, arranges towards the periphery in the cytoplasm. A large central various appears in the embryo sac the wall formation may start after sometimes from periphery towards the centre of the sac. Example: capsella, Euphorbia, Malva, Citrus, etc.
(2) Cellular Endosperm : In this type of endosperm the primary endosperm nucleus divides repeatedly followed by immediate wall formation, Therefore, endosperm becomes cellular from the very beginning Example : Adoxa, Balsam, Datura, etc.
(3) Helobial Endosperm : This type of endospermis of intermediate type between cellular and nuclear type. The first division of endosperm results in the formation two cells lawrger micropylar and smaller chalazal ends. As the subsequent division in the micropylar and begins to increase, the chalazed end starts of degenerate. Finally like that of nuclear endosperm, the multinucleate stage is followed by wall formation. Examples Asophodelus, Eremurus, etc.
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