What is endosperm ? Explain the types.

Explanation

The endosperm is a tissue produced inside the seeds of most of the flowering plants following fertilization. It surrounds the embryo and provides nutrition for the growing embryo.
Depending upon the mode of development, there are three types of endosperms, such as nuclear endosperm, cellular endosperm and Helobial endosperm.
Nuclear endosperm : In this, the primary endosperm nucleus undergoes . several mitotic divisions without cell wall formation. Thus a free nuclear condition exists in the endosperm. Eg: Coccinia, Capsella and Arachis.
Cellular endosperm: In this, cell wall formation takes place immediately after the primary endosperm nucleus divides into two nuclei. The cell division follows and forms the endosperm with many separate cells. Eg: Adoxa, Helianthus and Scoparia.
Helobial endosperm: In plants like Hydrilla and Vallisneria, the primary endosperm nucleus moves towards the base of the embryo, sac and divides into two nuclei followed by cell wall formation, leading to the formation of a large micropylar and small chalazal chambers. The nucleus of micropylar chamber divides several times leading to free nuclear condition whereas nucleus of chalazal chamber may or may not divide.