Question

Give reason why most zygotes in angiosperms divide only when a certain amount of endosperm is formed.

Answer 1

Zygote is formed from the fusion of the male and the female gamete. It grows further and develops into an embryo which further grows to become a plant. Now, we all know that for growth every living being requires some nutrients to nourish the cell and to aid in cell division.

Complete answer:
To solve the given question, we must know about the zygote and the endosperm of the angiosperm.
The endosperm is the storage tissue. Its main function is to provide the developing embryo the necessary nutrients for its growth. The endosperm might completely be used during the development of the growing embryo or some of it might still be left in the seeds.
Therefore, the correct answer to the question will be that most zygotes in angiosperms divide only when a certain amount of endosperm is formed because to divide the zygote need nutrients which it gets from the endosperm.

Note: The endosperm develops from the primary endosperm nucleus.It must be noted that there are three different types of endosperms:

Nucellar Type- In this type the division of the primary endosperm nucleus is not followed by cell wall formation. Hence, many free nuclei lie in the cytoplasm.
Cellular Type- In this type, the division of the primary endosperm nucleus is followed by the cell wall formation. Hence, many different cells are formed.
Helobial Type- In this type, the wall formation takes place only after the first division, but the subsequent divisions are free nuclear divisions.