A - Which one of the option shows the correct labelling of the parts marked as A, B, C and D in a typical structure of dicotyledonous seeds ? 

Correct Answer : B.

In the given figure of dicotyledonous seeds, the structure marked as A, B, C, D and E are respectively hilum, micropyle, plumule, cotyledon and radicle. Hilum is the scar on a seed marking the point of attachment of the developing seed vessel to the fruit. Micropyle is a small opening or pore present just below the hilum. It is the way of entry of water into the seed. Plumule is the developing bud of a plant embryo, situated above the cotyledons and consisting of the epicotyl and immature leaves. Cotyledon is an embryonic leaf in seedbearing plants, one or more of which are the first leaves to appear from a germinating seed. Radicle is the first part of a seedling (a growing plant embryo) to emerge from the seed during the process of germination. The radicle is the embryonic root of the plant, and grows downward in the soil (the shoot emerges from the plumule).