Transcript The War of the Roses

The War of the Roses
Case Study 1, Part 2
When Jason went back to school he took
a sample of leaves from his mother’s rose
bush with him. “I’ll show these to Professor
Jackson and Professor Perkins and see if
they’ll tell me what’s up with the roses. I’m
sure they’ll know, and they can tell me what
Mom should do about it.”
Professor Jackson was out, but Professor
Perkins was in her lab, where she was busy studying
diseases that affect apple orchards. “Sure, I’ll look at
it,” she said. “Apples are in the rose family, and there
are some shared diseases.”
When Professor Perkins looked at the rose
leaves, she smiles. “Jason,” she said, “you should
recognize this from your textbook. It’s a common
problem of roses.”
“Um, really?” Jason asked. “What is it?”
“Oh, no,” Professor Perkins replied. “I’m not
letting you off that easy. I want you to tell me what it
is. First, is it a disease, an insect problem, or
something your mother is doing wrong?”
Jason looked puzzled. “Well… since she’s
treating all her roses pretty much the same, I don’t
think it’s something she’s doing. But then again, if it’s
a disease or an insect, wouldn’t all of the roses be
affected the same way?”
“Not necessarily,” Professor Perkins replied. “As
with most plants, some varieties are more diseaseresistant. So how can we find out what is causing
these spots?”
“Look at them under the microscope?” Jason
guessed.
“That would be a good start. It might tell us
whether we’re dealing with a disease, or very tiny
insects.” Professor Perkins helped Jason take a
small sample from the leaf surface and put it under a
microscope.
Under the microscope
“So what do you see?” Professor Perkins
asked.
Jason pondered for a moment. “The cells
of whatever is on the roses look long and
stringy. Fungus cells look like that. Those
smaller cells look like spores. Is it a fungus?”
“That’s a good hypothesis,” Professor
Perkins said. “How can you find out if you’re
right or not?”
Question Set 2
1.
2.
3.
Is the problem with the roses a disease, an
insect problem, or something to with the
way the roses were cultivated? How do you
know? List at least three sources of
information that support your answer.
Why is the problem affecting some of Mrs.
Cook’s rose bushes, but not others?
Why is it more difficult to diagnose a plant
disease than a human disease?
Write a summary
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Explain how the disease affects plant tissues,
growth, and the transport of water and
nutrients.
If you were Jason, what steps would you
recommend your mother take to solve the
problem with her roses? List several
measures that can be taken, and the
advantages and disadvantages of each.
To turn in:
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Question sets 1, and 2
Plant disease sheet
Summary
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Turn in by Wednesday, April 30
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