Question

In cereals, one or few outermost layers of the endosperm become highly specialized morphologically and physiological and constitute the aleurone tissue. Which of the following statements regarding aleurone tissue (or aleurone cells) is incorrect?
(A) Aleurone cells are characterized by the presence of thin walls and vacuolated cytoplasm with single small nucleus
(B) Aleurone grains, rich in proteins are present in these cells
(C) Aleurone grains present in aleurone cells are closely associated with sphaerosomes
(D) During seed germination, the reserve food endosperm is digested by the activity of certain hydrolytic enzymes secreted by aleurone cells.

Answer 1

Hint: Aleurone cells are the cells that are capable of producing many hydrolytic enzymes that are responsible for breaking down the endosperm compounds which in turn provide nutrients to the embryo for the growth and development.

Complete Answer:
- Aleurone cells are present in one of the layers of the endosperm. Aleurone layer is the outermost layer of the endosperm and yields the aleurone. This layer is also known as peripheral endosperm.
- Aleurone is the protein found in the matured seeds and the grains. This produces many enzymes and organic acids to maintain the acidity of the endosperm.
- At the time of germination, the embryo releases the enzyme gibberellin which helps in triggering the aleurone cells to release acids and enzymes. These cells have thick walls and non-vacuolated cytoplasm. This aleurone membrane is surrounded by the sphaerosomes.

Thus, the option (A) is correct.

Note: The example for the crops containing aleurone layer is the cereals like rice, barley etc. And this layer helps in the production of nutrients for the seed growth. These possess two types of inclusion, globoids and protein carbohydrate bodies.