Question

Read the following statements related to embryogeny in plants and select the incorrect statements.

I. The early stages of embryo development are different in monocotyledons and dicotyledons.
II. Most zygotes divide only after a certain amount of endosperm is formed to ensure nutrition to the developing embryo.
III. Endosperm is completely consumed by developing embryos before seed maturation in coconut.
IV. The zygote gives rise to the proembryo and subsequently to the globular, heart-shaped and mature embryo.
[1 mark]

• A. I, II and III
• B. I and III
• C. II, III, and IV
• D. III and IV

Answer 1

The correct option is B I and III

The process of development of a mature embryo from zygote is known as embryogeny.

The zygote (oospore) divides immediately after the first division of the primary endosperm nucleus. Further divisions of this two celled structure give rise to proembryo. Practically there are no fundamental differences in the early stages of the development of the embryos of monocots and dicots. Hence statement I is incorrect.

In coconut the endosperm is not completely consumed by the developing embryo. Hence the mature seed has an endosperm. The coconut water is a free-nuclear endosperm and the white kernel is the cellular endosperm. So statement III is incorrect.

The development of zygote into an embryo begins after a certain amount of endosperm is formed. This is because the developing embryo needs nutrition. The endosperm is a nutritive tissue with reserve food materials which provide nourishment to the developing embryo. So statement II is correct.

The zygote initially gives rise to proembryo which eventually develops into globular, heart-shaped and finally into a mature embryo. Hence statement IV is correct.

Figure : Embryogeny