Embryo of Dicot Seeds

Materials Required

Pea Seed

Real Lab Procedure

  1. Take some pea seeds and put them in a beaker containing distilled water.
  2. Soak the pea seeds overnight.
  3. Take one seed from the beaker using a forceps and place it in a watch glass.
  4. Remove the seed coat of the pea seed, using the forceps and the needle.
  5. Pick the seed using the forceps and place it on the stage plate of the dissection microscope.
  6. Separate the two cotyledons of the pea seed using the forceps and the needle.
  7. Observe the seed through the dissection microscope. 

Observations

  • Pea seeds are round in shape.
  • One end of the embryonic axis called the plumule, lies enclosed between the two cotyledons. It develops into the shoot.
  • We can see a epicotyl and a hypocotyl on each seed, which is located above the root and below the stalk of the cotyledon.
  • The other end of the embryonic axis called the radicle, protrudes outside the cotyledons. This develops in to the root.
  • The pea seed contains two thick fleshy cotyledons which are foods storage organs.
  • Since two cotyledons are seen in pea seeds, they are dicot seeds. 

Gram Seed

Real Lab Procedure

  1. Take some gram seeds and put them in a beaker containing distilled water.
  2. Soak the gram seeds overnight.
  3. Take one seed from the beaker using a forceps and place it in a watch glass.
  4. Remove the seed coat of the gram seed, using the forceps and the needle.
  5. Pick the seed using the forceps and place it on the stage plate of the dissection microscope.
  6. Separate the two cotyledons of the gram seed using the forceps and the needle.
  7. Observe the seed through the dissection microscope.

Observations

  • Gram seeds are round in shape.
  • We can easily identify a scar called hilum.
  • A micropyle can be observed on the gram seed through which the seed imbibes water.
  • The gram seed contains two thick fleshy cotyledons that are foods storage organs.
  • We can observe a plumule on the gram seed which giving rise to the first true leaves.
  • The radicle is the embryonic root inside the seed which grows downward in the soil.
  • Above the radicle we can see an embryonic stem or hypocotyl.
  • Since two cotyledons are seen in gram seeds, they are dicot seeds.

Red Kidney Bean

Real Lab Procedure

  1. Take some seeds of red kidney bean and put them in a beaker containing distilled water.
  2. Soak the bean seeds overnight.
  3. Take one seed from the beaker using a forceps and place it in a watch glass.
  4. Remove the seed coat of the bean seed, using the forceps and the needle.
  5. Pick the seed using the forceps and place it on the stage plate of the dissection microscope.
  6. Separate the two cotyledons of the bean seed using the forceps and the needle.
  7. Observe the seed through the dissection microscope.

Observations

  • The beans are kidney shaped.
  • There is a scar along the notch called the hilum.
  • A small pore called micropyle is located at one end of the hilum.
  • One end of the embryonic axis called the plumule lies enclosed between the two cotyledons. It develops into the shoot.
  • We can observe a hypocotyl which is an embryonic stem.
  • The other end of the embryonic axis called the radicle protrudes outside the cotyledons. This develops in to the root.
  • The kidney bean seed contains two thick fleshy cotyledons that are foods storage organs.
  • Since two cotyledons are seen in bean seeds, they are dicot seeds.

Simulator Procedure (as performed through the Online Labs)

  • To change the type of the seed use the drop down list, ‘Select the seed type:’
  • To change the sample seed use the drop down list, ‘Select the sample seed:’
  • Drag the forceps towards the seed and remove the seed cover.
  • Drag and drop the seed onto the stage of the microscope using the forceps.
  • Drag the needle and forceps toward the seed to separate the two cotyledons.
  • Click on the eye piece of the compound microscope to enlarge the view of  seeds.
  • Drag and place the correct choice to the corresponding part of seed embryo. (If the choice is wrong, the selection goes back.)
  • Click on the information icon to see the inference.
  • You can redo the experiment anytime by clicking on the ‘Reset’ button.

Precautions

  • Seed should be soaked overnight in distilled water.
  • Be careful when removing the seed coat from the seed, to avoid damage to it.