HOW DOES IT WORK?
In the 3 experiments the theory of how water move, is pulled through a plant and the pathway it takes was observed by students.
Experiment 1: The study of the spontaneous movement of water: Capillary
Time allocation: 45 Min
The food colouring is added to water so that the movement of water is easily visible in the capillary tube apparatus. The water is then poured in the capillary tube apparatus. The capillary tube apparatus is a collection of tubes of various diameter on a stand. Water has a very distinctive “vicosity” meaning its affiliation to spread it surface area to relieve surface tension , this affects how it will move up the capillary tubes of different diameter. This is seen in the experiment.
Experiment 2: The study Root pressure in plants
Time allocation: 45 Min
The plant is cut off at the stem so that all the leaves and flowers are gone and only the primary stem and roots remain in the soil. The glass tube is attached to the stem by using the rubber tube and wired so that it is water proof and sturdy; the glass tube is held up straight by the retort stand and clamp. When the water is added to the pipe, paraffin is added to prevent evaporation of the water from the tube, and the water level was marked. As the roots are watered, they apply pressure and “draw up” water from the soil, subsequently the water level will rise in the tube.
Experiment 3: The pathway of water through plant tissue
Time allocation: 45 Min
The dye in the water allows us to track the movement of water in the stem and can be seen in the petals of the flower where it has stained the colour. When small cross section of the stem is viewed under the microscope the students can identify where the water moved through the stem.
Experiment 1: The study of the spontaneous movement of water: Capillary
AIM
Time allocation: 45 Min
To investigate the spontaneous movement of water through tubes with different diameters.
APPARATUS:
- 100 ml glass beaker
- Capillary tube apparatus
- Dye in dropper bottle
- Water
METHOD:
- Half fill the beaker with water.
- Add sufficient ink to dye the water and make it clearly visible.
- Fill the capillary tube apparatus with the beaker of water.
- Place three capillary tubes of different diameters in the beaker.
- Observe the level of water in each capillary tube.
OBSERVATION:
Draw the capillary tubes and indicate level of water in each, using the scientific drawing method.
PRECAUTIONS
Use a sharp scalpel to cut the stem to ensure that xylem cells are not damaged.
Add oil/paraffin over the water in the tube to prevent evaporation of water.
The potted plant must be well water prior to the experiment to
The rubber tube must be airtight to Chemicals
Paraffin First aid measures:
Eye contact: Irrigate thoroughly with water. If discomfort persists obtain medical attention.
Inhalation: Remove from exposure.
Skin contact: Wash off thoroughly with soap and water.
Ingestion: Wash out mouth thoroughly with water. In severe cases obtain medical attention.
Spillage: Spilt material may lead to slippery surfaces.
Firefighting measures: – Combustible if substance floats on surface of water. – Extinguish with foam, dry powder, carbon dioxide or vaporising liquids – Handling: Change contaminated clothing. Wash hands after working with substance.