EXPERIMENT 5 DB014

BIOLOGY DB014

EXPERIMENT
5

POLLEN GERMINATION

DB014 Lab Manual

EXPERIMENT 5: POLLEN GERMINATION

Course Learning Objective: Conduct basic biology laboratory work on
microscopy, tissues, genetics information, pollen germination and plant growth by
applying manipulative skills.
(P3, CLO 2, PLO 2, MQF LOD 2)

Learning Outcomes:
At the end of this lesson, students should be able to:
i. Identify the various shapes and structures of pollen grains.
ii. Explain the reproductive structure of flowering plant.

Student Learning Time (SLT):

Face-to-face Non face-to-face

2 hours 0

Introduction

The growth of a pollen tube is a fascinating phenomenon. Pollen grains are
morphologically simple, small structures which contain two nuclei when
released from the anther at anthesis. When a viable pollen grain lands on the
stigma of a compatible flower, it produces a tube several hundred to several
thousand micrometers long in which the pollen nuclei travel to the ovary of
the flower. The process of tube formation is a relatively uncomplicated
example of growth and development. Pollen germination represents a short,
yet very critical event in a series of steps leading to the double fertilization of
the ovule.

Experiment 5.1: Pollen germination

Apparatus

Compound microscope
Cavity well slides and cover slips
Dropper
Dissecting microscope
Dissecting needle
Scalpel/ Razor blade/ lancet

Updated: 20/05/2020 18

DB014 Lab Manual

Material
Hibiscus and Spider Lily flower

Procedures and Observations

1. Add 1-3 drops of water on a cavity well slide and transfer pollen
grains onto it.

2. Cover with a cover slip.
3. Observe the pollen grains under a compound microscope using 40x

objective lens.
4. Draw and label your observation.
5. Remove the sepals and petals from hibiscus flower by gently pulling

them off the receptacle.
6. Locate the stamen, each of which consists of a thin filament with a

pollen-filled anther of the tips. Note the number of stamen.
7. Locate the pistil. The stigma at the top of the pistil is often sticky.

The style is a long, narrow structure that leads from the stigma to the
ovary.
8. Observe the stamen and pistils of the hibiscus flower with dissecting
microscope.
9. Draw and label the male and female reproductive system of hibiscus
flower.

Questions:

1. Compare the hibiscus and spider lily pollen grain structure.
2. Why stigma at the top of the pistil is often sticky?
3. Why pollen is important in fertilization?

Updated: 20/05/2020 19