What is endosperm ? Describe types of endosperm.

The primary endosperm cell divides repeatedly and forms a triploid endosperm tissue. The cells of this tissue are filled with reserve food materials and are used for the nutrition of the developing embryo. It has three types : Nucleated, Cellular, Hellobial.

The cells of this tissue are rich with stored food and provide nutrition to developing embryo.

$(a)$Free nuclear endosperm : It is the most common type of endosperm development, the $PEN$ undergoes successive nuclear divisions to give rise to free nuclei. This stage of endosperm development is called free nuclear endosperm.

$(b)$ Multicellular endosperms : Nuclei are arranged in periphery region and big vacuole is formed in centre of endosperm. Then division of cytoplasm starts. This process also starts from periphery and leads towards centre and multicellular endosperm comes into existence.

The coconut water from tender coconut is nothing but free nuclear endosperm (made up of thousands of nuclei) and the surrounding white kernel is the cellular endosperm.

Endosperm may either be completely consumed by the developing embryo (e.g. pea, groundnut beans) before seed maturation or it may persists in the mature seed (e.g. caster and coconut) and be used up during seed germination.