Materials required

Petunia flowers, beaker containing water, slide, cover slip, cotton blue stain, glycerine, distilled water, forceps, filter paper, watch glasses, needle, blade, bunsen burner and wire gauze and a compound microscope.

The Procedure

Real lab Procedure

Take one petunia flower from the watch glass.
Using a blade, tear off the the petals longitudinally without damaging the carpel.
Using a forceps, take out the stigma along with style from the carpel and place it on a watch glass.
Take a beaker containing water and heat it over the Bunsen burner.
Using a forceps, transfer the stigma into the beaker containing boiling water.
Boil it for 5 to10 minutes to soften the tissues.
Take a few drops of cotton blue solution in a dropper and transfer into a watch glass.
Using a forceps, transfer the stigma into the watch glass containing the cotton blue solution.
Let this remain in the cotton blue solution for 3 to 5 minutes.
Pour few drops of distilled water into a watch glass.
Using a forceps, take the stigma from the cotton blue solution and place it on watch glass containing water to remove the excess stain.
Take glycerine in a dropper and pour one drops at the center of a dry glass slide.
Using the forceps, place the stigma onto the slide containing glycerine.
Take a cover slip and place it gently on the stigma with the aid of a needle.
Now, gently press the cover slip using the blunt end of a needle.
Using a filter paper remove the extra glycerine.
Place the slide under the compound microscope and observe the pollen tube growth.

Simulator Procedure

Drag and drop the slide onto the stage of the compound microscope.
Click on the eye piece of the compound microscope to view the sample.
To change the power of the lens, you can choose a lens from the ‘Select objective lens’ drop down list.
For coarse adjustments, you can either click on the left and right arrow of ‘Coarse adjustment’ knob, seen on the left control panel.
For fine adjustments, you can click on the left and right arrows of ‘Fine adjustment’knob which seen on the left control panel.
To observe each part, you can click on the four way directional arrow of ‘Slide adjustment’ seen on the left control panel.
Mouse over the sample to view the corresponding labelling.
You can repeat the experiment by clicking on the ‘Reset’ button.

Observation

The pollen grain is uninucleate (has one nucleus) in the beginning. At the time of liberation, it becomes 2 celled, with a small generative cell and a vegetative cell.
In the nutrient medium, the pollen grain germinates. The tube cell enlarges and comes out of the pollen grain through one of the germ pores to form a pollen tube.
The tube nucleus descends to the tip of the pollen tube. The generative cell also passes into it. It soon divides into two male gametes