SPRING HAS SPRUNG Water Movement in Plants

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SPRING HAS SPRUNG(Water Movement in Plants)

• By
• Karen Roberts

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• Movement of Water in Plants
• Do the Science lab.
• Heres what youll need.
• O.K., so heres the challenging question.
• Web links

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• With the coming of spring the days get longer,
  the air gets warmer, and the birds begin to sing.
  As you look around, you may see many changes
  taking place but the most stunning transformation
  has to be in the plants.
• Almost magically, barren branches start to bud,
  brown grass turns green, and tiny little shoots
  push up through the soil.
• How does this happen?
• Does mother nature need a wakeup call?

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• Well, in a sense, yes. But one way that plants
  awaken is with water.
• In fact, you could say that when the water starts
  flowing, its keen to be green!!

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• Ive got a challenge for you that lets you get to
  the bottom of how water gets to the top of the
  plant. First a little background information on
  the subject!

• How does water move around in plants?
• Vascular system Phloem-food conducting
  tissue. Xylem-water conducting
  tissue. The xylem tissue forms narrow tubes in
  which capillary action helps move water upward.
• Do the leaves pull it up, or are their other
  forces at play?

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• Water and minerals absorbed by roots of a plant
  move up the stem to the leaves, while sugar
  formed by photosynthesis moves from leaves to
  stems and the underground root system. Plants
  have tissues specialized for conduction which
  make up the vascular system. (xylem and phloem)
• Other factors involved in upward movement of
  water are osmotic pressure and transpiration
  pull.
• Osmotic pressure contributes to upward movement
  because water moves from areas of higher
  concentration (soil) to areas of lower
  concentration (roots). Transpiration is the loss
  of water from leaves. Transpiration pull is the
  pulling up of water into the leaf to replace the
  water lost by transpiration or used by
  photosynthesis.

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• Heres what youll need to begin.

• 2 large glasses of water.
• Some red food coloring.
• 2 fresh stalks of celery with leaves.
• A spoon.
• A plastic knife.

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Now for the Lab!

• Begin by putting 2 or 3 drops of food coloring in
  each glass of water and mix them up with the
  spoon.
• Take the celery stalk and remove all the leaves
  from it.
• Leave the other alone.
• Use the knife to cut about 1 centimeter up from
  the bottom of each stalk and place each stalk in
  one of the glasses with the red water.

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• Put the two glasses, each containing a celery
  stalk, side by side in direct sunlight (or under
  a lamp) and allow them to sit for about 24 hours.

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OKAY, SO HERES THE CHALLENGE QUESTION

• Which stalk of celery do you think will drink
  up the most water?
• The one with leaves or the one without leaves?

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• Before starting the experiment write your
  predictions.
• After youve let the celery sit for 24 hours, cut
  off the tops of the celery to see if the inside
  is dyed red.

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• Do leaves help to pull up the water, or does it
  get through the plant by some other means?
• I know youre dying to find out, so get busy
  and make your predications!!

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What Are We Going To Learn

• Using food coloring, we are going to track the
  movement of water through two celery stalks-one
  with and one without leaves.
• Observe the path that water takes to get to a
  leaf.
• Predict how leaves affect plants absorption of
  water.
• Observe the capillary action in plants.

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Web Links

• For more information on plants, try these Web
  sites.
• Welcome to Missouri Botanical Garden
• http//mbgnet.mobot.org
• University of Wisconsin-Madison Botanical Garden
• http//www.wisc.edu/botany/Garden/