Science - Biology - General Biology - 2 Germination of seeds and
growth of plants (P8011300)
2.9 Construction of a plant seed
Experiment by: Phywe
Printed: Oct 8, 2013 10:42:20 AM
interTESS (Version 13.06 B200, Export 2000)
Task
Task
What does a plant seed consist of?
Investigate a plant seed and find out what it consists of.
Use the space below for your own notes.
Logged in as a teacher you will find a button below for additional information.
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Additional Information
The seed of a plant consists of the seed coat, the embryo and the endosperm into
which the embryo is embedded. Looking at the embryo, one can recognize some of
the later parts of the plants, such as the seed leaves (cotyledons) and the first true
leaves, the seed stalks and the roots (radicle). In the case of the bean seed, especially
the two large, withish,kidney-shaped seed leaves (cotyledons), which are below the
solid skin, are striking.
Given the number of the seed leaves (cotyledons), flowering plants (angiosperms)
were formerly divided taxonomically. Thus, the plants with one seed leaf
(monocotyledons) can be distinguished from the plants with two seed leaves
(dicotyledons). However, since it has been determined that the dicotyledons form no
natural group (they are paraphyletic), the feature (taxon) is the number of cotyledons
is no longer used for systematic classification of angiosperms.
Hints on Setup and Action
• Due to the swelling of the bean seed, at least two days are needed for the
performance of this experiment.
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Material
Material
Material from "TESS advanced Biology basic set General Biology, BIO" (Order
No. 15296-88)
Position No.
Material
Order No. Quantity
1
Petri dish, d = 100 mm
64705-00
1
2
Tweezers, straight, pointed, 120 mm
64607-00
1
3
Dissecting needle, pointed
64620-00
1
4
Magnifier, plastic, 5x, d = 30 mm
88002-01
1
Additional Material
Bean seeds
Material required for the experiment
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Setup and Action
Setup and Action
Put about 5 bean seeds in an open petri dish (100 mm), fill it about 2/3 with water and let the
seeds swell over night (Fig. 1).
Fig. 1
On the next day, pick out a seed that has swollen nicely (the skin wil have popped open) (Fig. 2).
Fig. 2
Peel off the tough skin with the tweezers or your fingers. Avoid damaging the seed or pulling
the seed leaves apart (Fig. 3).
Fig. 3
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Carefully bend the seed leaves apart (Fig. 4 & 5) and observe. Use the magnifying glass to have
a better look at the details.
Fig. 4
Fig. 5
Make a sketch of the bean seed on the Results page.
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Results
Results
Do a simple sketch showing all the parts of the bean seed and their position in relation to each
other.
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Evaluation
Evaluation
Question 1
Name the parts of the bean seed and add the names in the appropriate places in your sketch
on the results page.
Seed coat
Seed leaves (cotyledons)
(true) Leaves
Seed stalk (hypocotyl)
Radicle
Question 2
How many seed leaves has the bean seed? In seed plants we distinguish between one-seed-leaf
(monocotyledon) and two-seed-leaf (dicotyledon) plants. To which group does the bean plant
belong?
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The bean plant seed has two seed leaves. It belongs to the dicotyledons.
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