water movement in plants - carton 2 garden · 2018-11-14 · we often say we are “giving our...

© 2014 The National Gardening Association. All rights reserved. 23 We often say we are “giving our plants a drink” when we water them But unlike people, plants don’t have mouths to drink with Just how do plants take in water? And how does the water get up to all parts of the plant, which may be as much as hundreds of feet in the air in the case of some trees? Water’s journey into the plant begins at the roots, where it diffuses into the tiny root hairs found near the tips of the roots From here in most plants the water makes its way into the xylem, a type of plant tissue that acts like piping to carry the water throughout the plant The water moves upward in the xylem cells through capillary action, which occurs when the forces holding the water molecules together (called cohesion) and to the sides of the column of xylem cells (called adhesion) are stronger than the force of gravity Transpiration is the driving force behind capillary action When water evaporates through small pores in the leaves and flower petals it causes the pressure in the xylem to drop, making a suction force that draws the water up through the xylem cells by capillary action, in the same way that you take a drink by sucking up liquid with a straw An easy experiment using white carnations lets students see firsthand how water moves from the stem of a plant into the petals of a flower Set the white flowers in water dyed with food coloring and track the water’s movement by observing color changes in the petals Materials Needed • White carnations • Single –serving milk or juice cartons, cleaned • Water • Food coloring (any color) • Scissors STEP 1. Using scissors, cut down the carton to make a 3 inch high carton pot STEP 2. Fill the carton pot about two-thirds full with water Add 10-20 drops of food coloring to the water until it is dark in color STEP 3. Using the scissors, cut about ½-inch off the bottom of a white carnation stem Place the carnation in the carton pot with the stem in the water STEP 4. Check the carnation every few hours, observing and recording color changes in the petals It may take as long as 24 hours to observe these changes Water Movement in Plants sponsored by with support from

Upload: others

Post on 25-May-2020

3 views

Category:

Documents

0 download

Report

Download

Embed Size (px):

TRANSCRIPT

Page 1: Water Movement in Plants - Carton 2 Garden · 2018-11-14 · We often say we are “giving our plants a drink” when we water them . But unlike people, plants don’t have mouths

We often say we are “giving our plants a drink” when we water them . But unlike people, plants don’t have mouths to drink with . Just how do plants take in water? And how does the water get up to all parts of the plant, which may be as much as hundreds of feet in the air in the case of some trees?

Water’s journey into the plant begins at the roots, where it diffuses into the tiny root hairs found near the tips of the roots . From here in most plants the water makes its way into the xylem, a type of plant tissue that acts like piping to carry the water throughout the plant . The water moves upward in the xylem cells through capillary action, which occurs when the forces holding the water molecules together (called cohesion) and to the sides of the column of xylem cells (called adhesion) are stronger than the force of gravity . Transpiration is the driving force behind capillary action . When water evaporates through small pores in the leaves and flower petals it causes the pressure in the xylem to drop, making a suction force that draws the water up through the xylem cells by capillary action, in the same way that you take a drink by sucking up liquid with a straw .

An easy experiment using white carnations lets students see firsthand how water moves from the stem of a plant into the petals of a flower . Set the white flowers in water dyed with food coloring and track the water’s movement by observing color changes in the petals .

Materials Needed

• White carnations

• Single –serving milk or juice cartons, cleaned

• Water

• Food coloring (any color)

• Scissors

Step 1. Using scissors, cut down the carton to make a 3 inch high carton pot .

Step 2. Fill the carton pot about two-thirds full with water . Add 10-20 drops of food coloring to the water until it is dark in color .

Step 3. Using the scissors, cut about ½-inch off the bottom of a white carnation stem . Place the carnation in the carton pot with the stem in the water .

Step 4. Check the carnation every few hours, observing and recording color changes in the petals . It may take as long as 24 hours to observe these changes .

Water Movement in Plants