1997 WWLPT Biology Institute:
Life Cycles: Reproduction & Embryological Development
Laboratory Exploration: Pollen Tube Germination
Instructor's Objectives:
The students will observe the formation of a pollen tube containing the tube nucleus and sperm nuclei. The students will observe certain conditions that are necessary for the formation of the pollen tube.
Materials and Equipment Needed:
a flower with pollen, e.g., a lily
10 % sucrose solution
depression slides and cover slips
compound microscope
Procedure:
1. Add 1-2 drops of sucrose solution to the well of a depression slide.
2. Touch the anther of a flower to the sucrose solution to pull off some of the pollen.
3. Add a cover slip and observe every 5 minutes for one hour. Make a sketch of the pollen grain and its tube to show changes over time.
4. Repeat steps 1-3 using distilled water.
5. Repeat steps 1-3, but instead of sucrose solution, add water and small pieces of cut style.
Conclusion:
1. Which of the three substances: sucrose, water, or style extract caused the formation of pollen tubes?
2. What was the purpose of using plain water on one slide?
3. Which resulted in the formation of more pollen tubes, sucrose or extract from the style?
4. Why did the addition of sucrose or style extract promote the formation of pollen tubes?
Gametogenesis and Fertilization Home Page
Gametogenesis and Fertilization in Angiosperms
Gametogenesis and Fertilization in Mammals
Laboratory Exploration: Pollen Tube Germination
Supplemental Activities on Gametogenesis and Fertilization