Identification of the different parts of an embryo of a dicot seed (Pea, gram or
red kidney bean
Aim:
To identify the different parts of an embryo of a dicot seed
Material Required:
• Seeds of red kidney bean/gram
• Forceps
• Magnifying glass
• Cloth
• Petri dish
• Water
Procedure:
• Soak a few seeds overnight
• Next morning, drain the excess water out
• Now wrap the seeds in a clean and a moist cloth for a day, allow it to dry
• Next, carefully peel the seed coat
• With the help of forceps, dissect the seed so as to get two equal halves
• Examine with the help of a magnifying glass.
Diagram:
Dicot Seed
Observation:
The bean seed resembles the shape of a kidney. It has a convex and a concave side
A scar known as the hilum is observed on the slightly darker side of the concave side
A tiny pore known as the micropyle is located just adjacent to the hilum
The seed is enclosed by a seed coat
The embryo possesses two distinct and large cotyledons that resemble the shape of a
kidney and are white in color
Lateral attachment of the cotyledons to the curved embryonal axis is observed
Radicle is examined. It is the rod-shaped and lightly protrusive lower end of the embryonal
axis that is found placed towards the micropylar end.
The upper end of the embryonal axis exhibits the plumule
Hypocotyl is observed which is a section of the embryo axis found in between the radicle
and adjunct of cotyledon leaves
The epicotyl is also observed which is the section of the embryo axis between the adjunct
of cotyledon leaves and plumule
Conclusion:
Three principle parts of the embryo of dicot seeds are observed, they are:
• Cotyledons
• Plumule
• Radicle
Precautions:
Care needs to be taken while dissecting the seed as it may damage the seed
The cloth that is used to wrap the seeds needs to be moist.
