Class 12th Biology 2017 Set3 Delhi Board Paper Solution
Describe the development of an endosperm in a viable seed. Why does endosperm development precedes embryo development?
Endosperm development occur due to triple fusion. During the triple fusion, one of the male gamete fuses with the two polar nuclei of the central cell and give rise to primary endosperm cell (PEC) The Primary endosperm cell divides repeatedly and form a triploid endosperm tissue.
The most common type of endosperm development is free-nuclear, in which the PEC unergoes successive nuclear division to give rise to a number of free nuclei. The endosperm thus formed is called free nuclear endosperm. Subsequently cell formation occurs and the endosperm becomes cellular.
The endosperm thus developed is required to provide essential nutrients to the growing embryo. Therefore, enosperm development occurs before the embryo development.
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