EXPERIMENT 15

Objective
ldentification of the different parts of an embryo of a dicot seed (Pea, gram, or red
kidney bedn.

CONCEPTS
The flowering plants have been classificd on the basis of number of
cotyledons found in their seeds, such as
monocotyledons containing one cotyledon, and dicotyledons containing two cotyledons in each secd.
Most of the differences in their features can be seen with our naked
eyes in secds as well as in plants.
1 Seed is the reproductive unit formed from fertilized ovule
containing a protective coat, stored food and an
embryo.
1 Seed helps a plant to tide over unfavourable seasons as it has a dormant embryo and
impermeable secd coat.
Radicle is the embryonic tip that grows to form the root system of the plant.
Plumule is the embryonic shoot tip that grows to form the shoot system of the plant.
Cotyledons store food for the embryo.
Plumule

Epicoty

Point of attachment

Hilum
Hypocotyl
Hilum
Micropyle Radicie
Position of Radicle

Testaseed coat
Tegmen
Cotyledon
Parts of a dicot seed

Dicot seed

Seed coat Embryo

Testa Tegmen Cotyledons Embryonic axis

(First leaves)
Plumule Epicotyl Hypocotyl Radicle
(Future shoot) (Future root)

Materials Required
1. Germinated seeds of (pea, gram or red kidney beans)
2. Dissecting needle
3. A pair of forceps
4. Petri dish

119
 embryo
Cobjedons at tbetween
l
Hypocty attached
germinated. observations
file the
bearsportion
axis. Plurmule Embryo are cotyledons
Embryo Cotyledons
Embryonic
axis
Radicle end
the embryo your cotyledons the
opposite
breaking and
recordEpicotyl the
short hypocotyl to
colouredthe
without theand and
attached
observe coat plumule
forceps, practical yellow called remains
seed
dish. Embryo embryo.
and is
and without broad the node
petri side.cotyledons
your and axis
VI
needle Seed by large leaves cotyledonary embryonic
a
in broaderin
dissection occupied
a
beans two epicotyl.
coloured
of from rudimentary
help which
kidney Seed
coat Seed
coat is and the
the depression the seed called that
yellow of
to radicle care.
or with ram of axis bears seeds.
germinated so
gram and
labelled
diagram interior is utmost
carefully the care,
theswollen stalks.axis plumule
embryonic
geminated
seed
of between with great
along seed
Kidney
been whole embryonic
coat the Seed
Gram
short and
cotyledonary
node
coat with
seedup the shortnarrow axis
Micropyle partially
seedcotyledons
see open
this aneat seeda the of
the has
openeruly Hilum Micropyle by of portion
dicotEmbryo
the
only Remove
a Remove end
middle
Take Cut S.Draw Observations
Procedure a One The Use Open
Precautions
In
1. 2. 3. 1. 2. 3. 4. 1. 2. 3.