Class: Introduction to Plant Biology (Sophomore-level)

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Class Introduction to Plant Biology
(Sophomore-level) Teachable Unit General
Plant-Water Relations Our students already
understand - properties of water, adhesion,
cohesion, osmosis - plant anatomy - basic cell
structure Our students have prepared for lecture
by reading the assigned textbook chapter about
plant-water relations.
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• Learning goal
• Understand how water moves through plants
• Learning outcomes
• 1. Describe the pathway of water from soil to
  plant
• to atmosphere
• 2. Explain the processes that move water through
  plants
• 3. Analyze the effects of changing abiotic
  factors on
• water movement in plants

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Have you ever wondered?
http//www.youtube.com/watch?vw6f2BiFiXiM
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• Group work (that we are skipping)
• Draw a diagram of a tree and indicate
• the direction/path of the water flow through the
  tree.
• - Call group representatives to draw their group
• drawings on board.
• - Elicit comments on differences
• Come to group conclusion soil, plant,
  atmosphere
• Post the drawing

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• Group work
• Which of the following processes are involved in
• getting water to the top of trees?
• Osmosis Yes or No?
• Diffusion Yes or No?
• Active transport Yes or No?
• Capillary action Yes or No?
• Cohesion-tension Yes or No?
• make sure incorrect assumptions are corrected,
• with more time a conversation about each

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On your handout, indicate where these processes
occur
Group reps post results - discussion ensues
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How do trees get water to their tops?
Video about evapotranspiration
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You observe water droplets on the margin of
geranium leaves at 6 am but not at noon. Using
your knowledge of plant-water relations the
information below, explain this phenomenon.
6 am
12 pm
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(No Transcript)
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Match plants A to D with biomes 1 to 4
1.
C.
2.
A.
3.
B.
D.
4.
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Have students fill out the diagram
collectively on single large diagram (doc-cam,
big poster, etc) Teaching Strategy 1 Go
through the responses with them. Does anyone
disagree with certain responses? For each
process from roots to shoots, segue to
mini-lecture teaching slides. Let
students reevaluate their drawings. Teaching
Strategy 2 do mini-lecture and let students
reevaluate their drawings.
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Mini-lecture on each of the processes -their
properties -their limits in terms of
movement Osmosis gets water from soil into
roots Diffusion mainly occurs in leaf to
atmosphere because the atmosphere has very
little water vapor. Active transport doesnt
occur Capillary action gets you less than 1
meter above soil surface. Cohesion-tension is
the major mover. Group work revise your labels
and share upfront. Which processes are the most
important at each point?