Double fertilization is resported in plants of both castor and groundnut . However the mature seeds of groundnut are non-albuminous and castor are albuminus . Explain post fertilization events that are responsible for it.

Give reasons why: (i) Most zygotes in angiosperms divide only after certain amount of endosperm is formed. (ii) Groundnut seeds are exalbuminous and castor seeds are albuminous. (iii) Micropyle remains as a small pore in the seed coat of a seed. (iv) Integuments of an ovule harden and the water content is highly reduced, as the seed matures. (v) Apple and cashew are not called true fruits.

Which of the following plants have albuminous seeds ? (Wheat , pea black pepper ,castor, sunflower, groundnut , barley)

Post - Fertilization events do not include A.Formation of primary endosperm cell B. Maturation of ovules in seed C. Formation of ovary into fruit D. Formation of endosperm and embryo development

Select total number of albuminous seeds from the following Pea, Groundnut, Wheat, Maize, Barley, Castor, Sunflower

(a) Describe any two devices in a flowering plant which prevent both autogamy and geitonogamy. (b) Explain the events upto double fertilization after the pollen tube enters one of the synergids in an ovule of an angiosperm .

Read the following statements and find out the incorrect statement. a. Embryo development precedes endosperm development. b. Though the seeds differs greatly the early stages of embryo development (embrogeny) are similar in both monocotyledons and dicotyledons. c. A typical dicotyledonous embryo consists of an embryonal axis and two cotyledons. d. Endosperm may either be completely consumed by the developing embryo (e.g., castor and coconut) before seed maturation or it may persist in the mature seed (e.g., wheat, rice , pea, groundnut and beans). e. The coconut water from tender coconut is cellular endosperms and the surrounding while kernal is the nuclear endosperm.

Assertion : Ex-albuminous seeds do not possess any residual endosperm, as it is completely consumed during embryo development., Reason : Wheat, castor, pea and groundnut are all the examples of ex-albuminous seeds.

a) Explain the phenomenon of double fertilization. b) Describe the post-zygotic events leading to implantation and placenta formation in humans. Mention any two functions of placenta.