Engineering a Monocot Seed

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Engineering a Seed
Being illustrations, the following images are
meant for clarity of understanding, not 100
accuracy in colour or shape. Labels are
absolutely accurate. Underlined text is linked
to play proper pronunciation of that text.
Capitalized, bold and italicized text plays
animations. Such text is the same colour as the
animation it plays. Click text again to replay
the animations and pronunciations. Navigation is
via navigation buttons placed in the lower-right
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the presentation beginning. Pressing the esc
key on your keyboard will return you to your
lesson. Proceed when ready.
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Engineering a Seed (Monocot)
How do they get those great, big oak trees into
those tiny, little acorns? The same way they get
those wheat plants into those tiny, little wheat
grains and bean plants into bean seeds.
Without getting into the chicken or egg
debate, lets start with the seed to see what is
required for a moncot plant to develop.
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Engineering a Seed (Monocot)
On the illustration of the wheat seed (caryopsis)
at left are four linked hotspots which will label
parts of the seed exterior and explain their
purposes. After viewing each of the four slides,
click the button to return to this slide
for your next selection.
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Engineering a Seed (Monocot)
These fine, hair-like strands are called the
brush or beard. They denote where the kernel
was attached to the of wheat.
ear
Click your mouse inside the circled area on the
photo for magnification and more information.
The circled area on the picture at right shows
where the brush attaches the seed to the ear.
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Engineering a Seed (Monocot)
As the seed forms after pollination, it folds in
on itself creating a crease (like a seam) where
the two sides meet. There appears to be no known
purpose for the crease but different grains have
different creases which help identify their type.
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Engineering a Seed (Monocot)
Cheeks (I wonder how they got that name) are
the inward folds at the top of the grain which
meet with the crease. You are actually looking
at the kernel upside-down in this image, which
seems to suit further illustration better. They
seem to have no purpose. How do they result and
what do they do?
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Engineering a Seed (Monocot)
PERICARP
The (ovary wall, seed wall,
bran) surrounds the entire seed. It is made of
several layers of strengthening tissue and
protects the embryo and its starch reserves
inside.
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Engineering a Seed (Monocot)

• So, now we know what the seed looks like on the
  outside
• brush
• pericarp
• crease
• cheeks.
• Whats it look like on the inside?
• Advance the slide to find out.

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Engineering a Seed (Monocot)
Seeds of monocot plants are difficult to split
and, when they do, they tend to fracture rather
irregularly, revealing a single
or chamber within. The parts in this
chamber serve important purposes in the
morphology of the seed in the plants life cycle.
Well explore these as the presentation
progresses.
Cotyledon
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Engineering a Seed (Monocot)
Underneath the pericarp is the (part
of the seed coat). The testa provides additional
protection for the seed. A small hole, known as
the , allows the seed to absorb
enough water for germination to begin.
TESTA
micropyle
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Engineering a Seed (Monocot)
Underneath the testa is the outermost layer of
the endosperm known as the
layer. Aleurone cells are rich in starch
digestive enzymes needed for germination. It
also gives colour to the seed.  
ALEURONE
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Engineering a Seed (Monocot)
Underneath the aleurone layer
layer is the .
ENDOSPERM
The endosperm cells are rich in starch digestive
enzymes needed for germination. This part also
gives colour to the seed. The endosperm is not
all absorbed by the developing embryo as it is in
dicot seeds.
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Engineering a Seed (Monocot)
Germ
The is the business end of the
seed.

• It contains all the parts that activate on
  germination. These include
• cotyledon
• coleoptile
• first true leaf
• apical meristem
• mesocotyl
• coleorhiza
• radicle