Students observe animal pollinators on flowers and work to answer instructor-directed questions on topics such as which flowers
are more attractive, probability of visitation, and types of visitors attracted. Students may then design an experiment or observations
to test the hypothesis, analyze the data, and prepare a formal report on their findings.
At the conclusion of this lab...
- students will develop an appreciation for and understanding of the importance of mutualistic interdependence of
organisms in the coevolution of structures and behaviors,
- students will learn to identify common flowering plants, common insect pollinators/visitors to those plants, and
common pollination syndromes evident in those common plants and pollinators,
- students will compile, add to, and use a data base of flowering times, visitation rates, and a pollen reference
collection usable by other classes,
- students will learn to ask questions that generate testable hypotheses about pollination ecology, gain experience
designing experiments to test those hypotheses, and analyze and present results in scientific format.
Equipment/ Logistics Required:
* This handout and data sheets,
* Populations of flowering plants and visitors,
* Basic fuchsin gel,
* Dissecting needles for cutting and applying gel cubes, glass microscope slides, coverslips, and candle with matches or lighter (or dark paper and sunlight),
* Permanent markers for labeling slides; slide box and small insulated ice chest to keep prepared slides from melting,
* Microscopes with 100 power; counting grids,
* Insect nets,
* Ethyl acetate for stunning, or freezer,
* Hand lenses,
* Stopwatches or watches with second hand.
Summary of What is Due:
From this lab, students should submit the following:
- Responses to the following pre-lab questions due at the beginning of the first lab devoted to pollination,
- Define the following terms: coevolution, mutualism, pollination syndrome, insect, phenology, diurnal, parasitism, angiosperm.
- Differentiate between visitation and pollination, between pollination and fertilization, and between pollination and parasitism.
- Draw and label a “typical” flower, and describe the major functions of each part.
- Why do animals visit flowers? Describe the characteristics of animals that would make for a good pollinator.
What rewards do the plants provide?
- Do any visitors harm the flowers? Do any flowers harm their visitors?
- Students will submit data collected by their groups which will be compiled and distributed,
- Students will generate questions about the interactions they observed. These questions may be developed into testable hypotheses for
student projects, or may be included as part of their discussion sections for a research-style report using the compiled data,
- If student generated questions are investigated, a research-style report is required to present these data.
Principal Ecological Question Addressed:
How and why are animals attracted to flowers? How can animals and flowering plants act as selective
agents upon each other, resulting in coevolution of a mutualistic relationship?
Ecological Topic Keywords:
coevolution, pollination, floral phenology, mutualism
Science Methodological Skills Developed:
natural history observations in the field, classification and use of dichotomous keys, sampling to estimate population
size (of plants, flowers, pollen in loads), defining questions, formulating hypotheses, designing experiments, collecting
and presenting data, microscope use, graphing summarized data, and development of equations to predict probability
of visit, number of visits per flower, size of population
Pedagogical Methods Used:
based learning emphasizing a specific set of techniques (see also guided inquiry);
cooperative groupwork to generate and test hypotheses