Question

What is endosperm ? Explain various types of endosperms.

Answer 1

Endosperm is a tissue present inside the seeds of most of the angiosperms which appears after fertilization. It provides nutrition to the embryo. In angiosperms, endosperms are of three types:

(i) Nuclear type: It is the most common type of endosperm formation. In this type the primary endosperm nucleus gives rise to a number of free nuclei which remain as a peripheral layer and a large central vacuole appears in the embryo sac. Cell wall formation takes later leading to the formation of cellular endosperm. For example, Coconut, Areca.
(ii) Cellular type: In it, first division of primary endosperm nucleus is followed by wall formation, hence endosperm is cellular. For example, Datura.
(iii) Helobial Type: It is in between the nuclear and cellular types. Wall formation occurs after tThe first division of endosperm nucleus. A large number of nuclei are formed in it by free nuclear divisions. The nucleus of chalazal chamber divides to form free nuclei or may divide at all. For example, Drimya.