Question

discuss various type of endosperm and their occurrence​

Answer 1

Answer:

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.

Explanation:

Answer 2

Answer:

Three main types of endosperm development in flowering plants are: (i) Nuclear type (ii) Cellular type and (iii) Helobial type! The formation of endosperm is initiated by mitotic divisions of the primary endosperm nucleus (3N). The formation of endosperm occurs usually prior to the zygotic division.