This simple experiment demonstrates transpiration, the loss of water from leaves.
Things Required:
Growing plant
Plastic sandwich bag
Tape (cellophane)
Directions:
Place the sandwich bag over one leaf. Secure the bag to the stem with the tape. Place the plant in sunlight for two to three hours.
Observe the inside of the bag.
This Is What Happens:
The droplets of water collect on the inside of the plastic bag. The inside of the bag may appear cloudy due to the water in the air.
Science Behind It:
Plants absorb water from the soil through their roots. This water moves up the stem to the leaves where 90 per cent is lost through the pores of the leaf (stomata). Some trees lose as much as 15,000 pounds (6,810 Kg) of water within a 12-hour period. Plants can greatly affect temperature and the humidity of a heavily vegetated area. This loss of water through the stomata of the leaves is called transpiration.
