Question

The wheat grain has an embryo with one large shield-shaped cotyledon known as:

• A. Coleoptile
• B. Epiblast
• C. Coleorhiza
• D. Scutellum

Answer 1

The correct option is D

Scutellum

The correct option is D.

The explanation of the correct option:

1. The embryo of a grain of wheat, maize, or rice is positioned so that it rests laterally near the grain.
2. The embryo is made up of an upper, sizable cotyledon with a shield-like form known as the scutellum.
3. The scutellum adheres tightly against the endosperm and aids in the transfer of nutrients from the endosperm to the developing embryo during germination and seedling growth.
4. It is thought that the scutellum contains a protein transporter that helps starch travel from the endosperm to the embryo.

The explanation of the incorrect option:

Option (A):

1. In monocotyledons, such as grasses, the emerging shoot is protected by a pointed sheath called a coleoptile, in which just a few leaf primordia and the shoot apex of the monocot embryo are still enclosed.
2. Hence, it is an incorrect option.

Option (B):

1. Epiblast is an embryo's immature portion and is a flap-like structure.
2. Since it is near the cotyledon's growing portion and resembles other cotyledons in the dicot, it may be referred to as the second cotyledon but it is an undeveloped part.
3. Hence, it is an incorrect option.

Option (C):

1. In monocotyledon seeds, the radicle is encased in a protective tissue layer called the coleorhiza, coleorhiza, or root sheath.
2. The coleorhiza is the first component to emerge from the seed during germination, expanding via cell elongation.
3. Hence, it is an incorrect option.

Final answer: The wheat grain has an embryo with one large shield-shaped cotyledon known as Scutellum.