Understanding the Cotyledon in Velvet Grass Seed

The question asks about the specific name for the cotyledon found in a velvet grass seed. Velvet grass is a type of grass, and grasses belong to the group of plants known as monocots. Monocot seeds have a distinct structure compared to dicot seeds, particularly regarding the cotyledon.

In typical monocot seeds, the single cotyledon is specialized. It doesn't store much food but acts as a transfer organ, helping to move nutrients from the endosperm (storage tissue) to the developing embryo during germination.

Identifying the Cotyledon Name in Grass Seeds

In grass seeds, which are classic examples of monocots, the single cotyledon has a specific name:

• It is called the Scutellum.

The scutellum is a shield-shaped cotyledon that lies pressed against the endosperm.

Analyzing the Options

Let's look at the given options and understand what they represent in the context of a grass seed structure:

Based on the analysis, the scutellum is the correct term for the cotyledon in a velvet grass seed, which is a monocot seed.

Key Parts of a Monocot Seed (Grass Seed Example)

A typical monocot seed like that of velvet grass includes:

• Seed Coat (Testa): The outer protective layer. In grasses, it is often fused with the fruit wall (pericarp).
• Endosperm: The primary food storage tissue.
• Embryo: The young multicellular organism before it emerges from the seed. It consists of:
  • Scutellum: The single cotyledon, absorbing food from the endosperm.
  • Embryonic Axis:
    • Plumule: The embryonic shoot, covered by the coleoptile.
    • Radicle: The embryonic root, covered by the coleorrhiza.

Conclusion

The cotyledon in a velvet grass seed is specifically known as the scutellum. It plays a vital role in transferring stored food from the endosperm to the growing embryo during germination.

Revision Table: Grass Seed Structure

Additional Information: Monocot vs. Dicot Seeds

Understanding the difference between monocot and dicot seeds helps clarify the unique structure of grass seeds:

• Monocot Seeds (like grass):
  • Have only one cotyledon (Scutellum).
  • Endosperm is typically large and the primary food storage tissue.
  • Cotyledon primarily functions in nutrient transfer.
• Dicot Seeds (like bean, pea):
  • Have two cotyledons.
  • Cotyledons often store the food, and endosperm may be absorbed during seed development.
  • Cotyledons function in food storage and/or transfer.

This structural difference is a key characteristic used to classify these two major groups of flowering plants.