Question

Which of the following is Hilum of a starch grain formed of?
A) A special micro-grain of starch.
B) Proteinaceous centre
C) Lipid centre
D) Nucleic acid centre

Answer 1

Hint:Hilum is a scar or mark left on a seed coat by the former attachment to the ovary wall or to the funiculus (which in turn attaches to the ovary wall).

Complete answer:
All starch grains have a hilum, which is the point around which layers of protein are deposited. In tubers, bulbs, and rhizomes, the hilum is often off-center, with growth rings emanating outward from the hilum. Because of this off-center hilum. The hilum of a liberated seed is a small scar marking its former place of attachment. The short ridge (raphe) that sometimes leads away from the hilum is formed by the fusion of seed stalk and testa. A classification of seeds can be based on size and position of the embryo and on the proportion of embryo to storage tissue; the possession of either one or two cotyledons is considered crucial in recognizing two main groups of flowering plants, the monocotyledons and the eudicotyledons. The hilum on seeds is produced by the separation from its funicle or placenta. In spores, the hilum is formed by its detachment from the spore-bearing structure.

Thus, the correct answer is option B (Proteinaceous Centre).

Note: In many seeds, the micropyle of the ovule also persists as a small opening in the seed coat. The embryo, variously located in the seed, may be very small (as in buttercups) or may fill the seed almost completely (as in roses and plants of the mustard family) with the existence of radicle and plumule.