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How to Identify & Know the Function of the Structures of the Parts of a Seed

Imagine putting an astronaut to sleep and then creating a space capsule designed to keep him that way for months, years or even centuries. The capsule must not only transport the astronaut, but it must also feed and protect him until the external conditions are right for him to leave the capsule. This is what a seed does. Although it might look simple, inside you will find many important structures that nourish and protect a dormant embryonic plant until the conditions are right for it to germinate.

Things You'll Need

Scalpel

Instructions

- 1
  Examine the outside of the seed. This is the testa, or seed coat. It is often hard and encases the other parts of the seed to protect them from the outside elements.
- 2
  Split the seed in half from top to bottom with a scalpel. Notice whether you cut through a single section or whether you separated two existing sections. If the seed has only one section, it is a monocot. If it has two parts, it is a dicot.
- 3
  Find the meaty area that takes up most of the space inside the seed. In a monocot, this is the endosperm. In a dicot, it is the two cotyledons. Both structures provide food for the embryonic plant. In dicots, the cotyledons will become the first pseudo-leaves to appear on the sprout and will continue to provide food for the plant through photosynthesis until its true leaves appear.
- 4
  Find the structure that separates the endosperm and the embryonic plant in a monocot. This is the cotyledon, which transfers the food from the endosperm to the baby plant. Unlike the cotyledons in dicots, this will not appear above ground after the plant germinates.
- 5
  Find the small structure near the edge of the seed, surrounded by the endosperm and the cotyledons. Sometimes it will look like a tiny shoot. Other times, it might look like a folded organ of a lighter color near the seed coat. This is the embryonic plant.
- 6
  Find the leaf-like structure, or wrinkled portion of the embryo. This is the plummle, which will develop into the plant's leaves and provide energy for it through photosynthesis.
- 7
  Find the lower, tail-like portion of the embryo. This is the radicle, which will become the root, providing support and nutrients for the mature plant.
- 8
  Find the body of the embryo between the plummle and the radicle. The upper portion is the epicotyl, while the lower portion is the hypocotyl. Between these two halves, the embryo connects to the cotyledon. Both portions become the plant's stem, providing structure and transportation between the roots and the upper parts of the plant.

Nature