Anatomy of Seed Science Project Idea
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Written by Dee
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Monday, 09 July 2007 |
Science Project Idea on the anatomy of the seed.
Anatomy of the Seed- Science Project Idea
What are the parts of a seed?Soak a num ber of rather large seeds as peas, beans, or corn.Examine a bean seed.It will be noticed that there is a scar on one edge.To understand the cause of this scar, open a bean pod and note how the seeds are attached.While the seed is growing, what do you suppose passes through the little stalk by which the seed is attached to the side of the pod?The point of attachment of this little stalk to the side of the pod is called the placenta.What materials pass through the placenta?
Remove the seed coat and find two large structures that make up almost the whole bulk of the seed.
These are called seed leaves, and it will be noted that they are attached to a little stalk, the pointed end of which will later develop into the root of the growing bean plant.At the other end of the little stalk, and just beyond where the big seed leaves are attached, you will see two little plume-like structures which at first look like the parts of a fish's tail, but on closer examination prove to be small leaves.These leaves, with the very small stalk to which they are attached, will develop into the stem and leaves of the plant.
Altogether the bean seed is made up of a little plant called an embryo, of which two leaves are filled to such an extent with food material that they have become so thickened that they no longer look like leaves.These constitute the seed leaves.Compare the embryo making up the seed of the bean with a bean seedling.Pick out the corresponding parts.
Examine a soaked pea seed and endeavor to find the same parts that you found in the bean seed.In the same way compare the embryo of the pea seed with a pea seedling and note the corresponding parts.
A corn seed may be best studied if it is examined together with one which has begun to sprout.The part which corresponds to the root end of the little stem can easily be seen, as in whatever position the corn grain is kept this root end begins to grow downward.The other end, which begins to push upward to form the main part of the plant, is pointed and made up of tightly twisted leaves in much the same way that you can furl up a piece of paper leaving a sharp point at one end.
The seed leaf (there is only one) is not at all leaf-like in appearance but is embedded in stored food material which in the corn seed is outside of the embryo.The relation of the seed leaf to the stored food material can best be seen by cutting lengthwise and cross sections of soaked corn grains, and dipping the cut surfaces in an iodine solution.The stored food material, since it contains a very large amount of starch, becomes colored a very dark blue; while the parts of the embryo are colored very slightly.
It will thus be seen that the corn seed, although apparently so unlike the bean or pea seeds, also contains an embryo, or undeveloped plant, which consists of a seed leaf attached to a stalk, one end of which will develop into the roots, and the other end into the stem and leaves of the plant.
Examination of other seeds will show the same thing, so that we may conclude that the seed of a plant always contains an embryo or baby plant with considerable stored-up food which may either be in the seed leaves or outside of the embryo.
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Last Updated ( Sunday, 22 July 2007 )
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