Question

Aleurone layer takes part in
A. protein of delicate embryo
B. Enzyme synthesis
C. Transfer of food to cotyledons
D. Transfer of food from cotyledons to embryo tips

Answer 1

Hint: The seeds of various plants have cotyledons for storing the nutrition for the embryo. The endosperm is formed by the triple fusion between the pollen and the binucleate central cell. It is usually to support the embryo only. It usually vanishes after the fruit formation. In rare cases, it becomes edible in fruits. There can be one or two cotyledons in the embryo.

Complete answer:
The Aleurone layer is present in the monocotyledonous endospermic seed. It surrounds the endosperm. This layer is one cell thick.
The main work of this layer is to nourish the embryo in the seed. It is a protein rich layer of endospermic cells. Some secretions from this layer help in the germination.
This aleurone layer is present in rye, millet, rice, wheat etc. Aleurone cells of barley have lipids, proteins, sucrose and phytin.

> Option A: Protein of delicate embryo: It is the proteinaceous layer, does not specifically deliver proteins to the embryo.

> Option B: enzyme synthesis: The aleurone layer will release various enzymes responsible for the germination process and growth of the embryo.

> Option C: transfer of food to cotyledons: Cotyledons are the reserve of food for the embryo.

> Option D: transfer of food from cotyledons to embryo tips: This layer does not transport any material rather just synthesize enzymes.

Hence, the correct answer is option (B).

Note: The epidermis of the seed has the aleurone layer. During germination, it plays a vital role. It secretes hydrolases for breaking starch and proteins in endospermic cells. At maturity, the endosperm is sometimes completely consumed as in pea or beans.