Name: Fertilisation in Angiosperms
Uploaded: 2019-07-19
Duration: 10 min 16 s
Description: You surely have beautiful flowering plants on your lawn. Have you ever wondered about the classification of such plants? They are angiosperms, a topic this v...

Question

Explain different types of endosperm with suitable diagrams.

Accepted Answer

The endosperm is the triploid structure that provides nourishment to the developing embryo. It is formed by the triple fusion of male gamete with two polar nuclei. Based on the process of development, there are three types of endosperms: i) Nuclear ii) Cellular and iii) Helobial endosperm
i) Nuclear Endosperm— In this type of endosperm development, the primary endosperm nucleus forms many nuclei by free nuclear division. These nuclei get arranged on the periphery and a large vacuole is formed. It becomes cellular after some times by the formation of cell walls around the nuclei. The coconut water is an example of a nuclear type of endosperm.

ii) Cellular Endosperm— In this type of endosperm development, the primary endosperm nucleus divides into two nuclei and a cell wall is formed between these two nuclei. Each subsequent nuclear division is followed by cell wall formation. Example: Members of Gamopetalae class (Verbascum).

iii) Helobial Endosperm— This type of endosperm is of intermediate one of both the types of endosperms. In this type, the first division of the primary endosperm nucleus is followed by wall formation resulting in the formation of a large and a small cell. In the small cell, lying towards the chalazal end, free nuclear divisions take place and the cell wall formation does not occur. In the larger cell lying towards micropyle, each nuclear division is followed by cell wall formation. Thus, it is a mixed form of nuclear and cellular type of endosperm. Example: Members of the order Helobiales of monocot plants.

Explain different types of endosperm with suitable diagrams.

Important Questions on Sexual Reproduction in Flowering Plants

Learn and Prepare for any exam you want !