Double fertilization is reported in plants of both, castor and groundnut. However, the mature seeds of groundnut are non-albuminous and castor are albuminous. Explain the 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) ground nut 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. apple and cashew are not called true fruits.

How many of the following plants have endospermic seeds? Castor, Pea, Qrchids, Groundnut, Maize,Rice, Beans

(a) Draw a diagrammatic sectional view of a mature anatropous ovule and label the following parts in it : (i) that develops into seed coat. (ii) that develops into an embryo after fertilization. (iii) that develops into an endosperm in an albuminous seed. (iv) through which the pollen tube gains entry into the embryo sac. (v) that attaches the ovule to the placenta. (b) Describe the characteristic features of wind pollinated flowers.

(a) Draw a diagrammatic sectional view of a mature anatropous ovule and label the following parts in it : (i) that develops into seed coat. (ii) that develops into an embryo after fertilization. (iii) that develops into an endosperm in an albuminous seed. (iv) through which the pollen tube gains entry into the embryo sac. (v) that attaches the ovule to the placenta. (b) Describe the characteristic features of wind pollinated flowers.

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

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.