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Practicing Science 0.1 PREP FOR THE AP EXAM
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Using observation and experimentation
to investigate a horticultural problem

Background Scientific inquiry is often called upon to address prob-
lems that arise in society and industry. In 1916, British horticulturalists
were concerned with a disease that killed daffodils. Daffodils grow
from bulbs, which are large underground stems that store energy and
are seen in many plants, such as daffodils, tulips, and onions. However,
the disease caused leaves to wither, bulbs to become discolored, and
eventually death of the plant. The demise of the plants represented
a substantial loss of commercial production and income to the hor-
ticultural industry. While some suspected a fungus caused the plant
deaths, no one was able to determine the source of the problem.
The British Royal Horticultural Society took up the cause and assigned
the problem to James Kirkham Ramsbottom. At the time he was a
top student at the Royal Horticultural Society’s garden in Wisley, a
community near London.

Observation and Hypothesis Ramsbottom began by making
observations. He examined hundreds of diseased bulbs, preparing
microscopic slides and studying them closely. While he did see fungi,
Ramsbottom observed that all of the diseased bulbs contained a
parasitic worm, Tylenchus devastratix . Ramsbottom hypothesized that
the worm was the cause of the disease afflicting the plants and pre-
dicted that if he could devise a way to kill the worm without killing the
bulbs, the disease would be eliminated.
Experimentation Ramsbottom launched a series of experiments AP PRACTICE QUESTION
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where he examined a number of agents that might selectively kill the
worm while keeping the plant alive. He tried chemical treatments, James Kirkham Ramsbottom used the process of scientific inquiry
spraying the plants and dousing them. He experimented with both to figure out what was causing the death of daffodils. Organize the
gas and formaldehyde. He settled on the use of heat. Ramsbottom description of his experiment by identifying the following:
immersed the bulbs for different amounts of time in hot water. The 1. The scientific (testable) question
photograph shows the removable wire basket and copper boiler that 2. The hypothesis
permitted Ramsbottom to heat the daffodil bulbs for different periods 3. The independent variable

of time. He determined that soaking them in 110°F (43°C) water for 4. The dependent variable
2 to 4 hours left the bulbs intact while the parasite was eliminated. 5. The experimental group
Untreated, infected daffodil bulbs failed to grow, died, and did not pro- 6. The control group
duce flowers. The heat-treated daffodil bulbs grew normally and pro-
duced the sought-after plant and flower. Today, the Ramsbottom heat
treatment is still used in virtually the same manner as he developed it.
SOURCE
Flower Preservation, 1916. The Scientist, 2:64. Photo: RHS Lindley Collections

Analyzing and Interpreting Data or rejected on the basis of data, and our understanding of the
After conducting an observational or controlled experiment, world is ultimately built on a foundation of data.
the scientist has a collection of data. Data are the bedrock of What types of data will you encounter in your AP ®
science. Biologists collect, analyze, and interpret data to answer Biology course? Data can take many forms, including
questions about the natural world. Hypotheses are supported observations, measurements, and facts. Data can be qualitative

MODULE 0 IntroductIon 9

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