Report The Results of Lab Work

By :
Natasya Annisa Putri
8 RSBI1
5 Junior High School Cirebon
Objective
 Identifying the main sites of transpiration
Device and Materials
 2 Celery
 2 beaker
 Colored water ( champolay )
 Scissors or cutter

Work Procedure
 Step 1 : Place celery stem, with its leaves in fact, in a beaker of colored as
in figure.
 Step 2 : Place a second stem of about the same weight, but with all its
leaves removed, in another beaker of colored water.
 Step 3 : After 20 minutes, removes both stalks and cut the stem regular
interval to see how far the colored water had risen



Experiment

1. Prepare equipment needed
2. Pour colored water to beaker
3. Add water




4. Enter celery to beaker, and wait until 20 minutes.
5. After 20 minutes, cut celery and reserving a few leaves
6. And after 20 minutes ,celery stem change be red.


Results of Experiment
• Celery stem it to absorb the colored solution because it has an active xylem.

Conclusion
Transpiration

The difference between transpiration and evaporation
Different from the evaporation transpiration / evaporation simpleas going on living tissue and is influenced by fisiologitumbuhan.
Transpiration mechanism

Stoma (singular) or the mouth of the leaves, most of thetranspiration takes place in this section.
Water is absorbed into the roots by osmosis through the root hair, most of the moves by water potential gradient through the xylem.Air in xylem vessels under great pressure karenamolekul fused polar water in the column continues a result of the evaporation which took place at the top. Most of the ions move through the epidermis simplas from the root to the xylem, and then up through the transport stream.
Transpiration rate is affected by plant size, levels of CO2, light, temperature, air flow, humidity, and soil water availability. These factors influence the behavior of stoma opening and closing is controlled by guard cell turgor pressure changes that correlate with high levels of potassium ions (K +) in it. During the open stoma, occurred between leaf gas exchange with the atmosphere and water will be lost into the atmosphere. To measure the rate of transpiration can be used potometer.
Transpiration in plants healthy even if it is inevitable and if excessive will be very harmful because the plant will wilt and even die.
Most of the transpiration takes place through the stomata is through leaf cuticle in smaller amounts. Transpiration occurs when plants open stomatanya to take carbon dioxide from the air to photosynthesize.
More than 20% of water taken by the roots released into the air as water vapor. Most of the water vapor ditranspirasi by high tumbuhantingkat derived from the leaves than the stems, flowers and fruit.
Transpiration transpiration stream caused the translocation of water and dissolved organic ions from roots to leaves via xylem.

Adaptation of plants to transpiration

Teak forests in Bojonegoro, East Javaduring the rainy season
Leaf
Plants such as teak and acacia trees to reduce evaporation bymeans abort leaves in summer.
In plants grains, and ginger-jahean liliacea, this type of deadlyplant leaves during the dry season. In the rainy season the leavesare growing again.

Example cactus: Melocactus curvispinus.

Plants that live in the desert or water-deficient environment (hotregion) such as cactus, have special strukturadaptasi to adjust to the environment. In plants that are in hot areas, if a leaf is hairyleaves, small shape and sometimes the leaves changed to thornsand scales.
Wax layer serves to protect the leaf from excessive evaporationand insect disturbances



The mechanism of closing / opening

Some plants in the desert leaves close (shut) in the daytime andopen at night to avoid excess evaporation.

Root
Root system of plants in hot areas has roots that long, so it canabsorb more water.








Source : http://id.wikipedia.org/wiki/Transpirasi