• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

Conducting an experiment to find out what effect the surface area has on the rate of transpiration.

Extracts from this document...


Introduction: �In my investigation I plan on conducting an experiment to find out what effect the surface area has on the rate of transpiration. �Plants are autotrophic i.e. they make there own food (energy) through the process of photosynthesis. 6CO2 + 6 H2O --> C6H12O6 + 6O2 �For the above process plants require carbon dioxide and water as well as sunlight. They get the carbon dioxide from the air and water is absorbed from the soil through the process of osmosis. �Plants add considerable volume of moisture to the atmosphere. After absorbing water trough their roots, the water travels up the stem to the leaves where over 90% of the absorbed water is lost through the process named transpiration. The sun provides the energy required turning the water in the leaves to vapour, and then vaporised water diffuses out of the plant in to the atmosphere through stomata in the leaves. The diffusion of water out of plant reduces the pressure at the top of the plant, but a high pressure is created at the bottom of the plant so the water moves up the stem into region where it is needed. The loss of water vapour from the plants is called Transpiration. It is a passive process. ...read more.


There was a choice of two potometre: a simple potometer and a complex one with more syringes. Both were used in the pilot but simple potometre was preferred as it gave the reliable result and it was simple to set up. The pilot was carried out by the following procedure. 1. First of all a small branch with few leaves was cut and put in water so the xylem tunes don't become dried. A potometer was filled with water. 2. A small piece was cut from the stalk of the branch so damage or dried xylem tubes can be removed. Then the stalk was attached to the potometer under water. Making sure there were no air bubbles present in the potometer. 3. One bubble was introduced this will be used as a marker. The distance for the air bubble to move was set at 5 mm at first trial. Time for air bubble to move this distance be recorded. Then one leaf was removes and same procedure was repeated and time was recorded. Number of leaves Distance moved (mm) Time taken for the distance to move (s) 1st trial 2nd trial 9 5 157.5 157.3 8 5 162.4 162.7 9 1 31.0 32.0 8 1 45.1 44.5 9 2 ...read more.


Water up take I roughly the same as transpiration. �The graph shows a positive correlation but the line is not straight passing through the origin, meaning it is not directly proportional as predicted. I will explain why the results desired were not obtained as I analyse the data. Summary tables. Number of leaves on the shoot Average time taken (to move 2mm) (secs) 9 71.0 8 57.6 7 55.0 6 50.8 5 56.9 4 62.8 3 71.0 2 75.4 1 82.0 Area of the leaves (m2) Number of leaves Rate of transpiration (1/s) 0.017 9 0.014 0.015 8 0.017 0.013 7 0.018 0.012 6 0.020 0.010 5 0.018 0.008 4 0.016 0.006 3 0.014 0.004 2 0.013 0.002 1 0.012 I said in my prediction that bigger the surface area of the leaves faster the rate of transpiration due to the more stomata available. But this was found not be true as we can see in the above summary table that when there were nine leaves and area was 0.017m2 the transpiration was slower than when there were six leaves on the shoot and total leaves surface area was 0.012m2. So the part of the graph marked A can be considered uncharacteristic. But we can also prove that these three readings (A) are true. �Leaves are plants food producing organ. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our GCSE Green Plants as Organisms section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related GCSE Green Plants as Organisms essays

  1. Marked by a teacher

    Biology lab - transpiration

    5 star(s)

    What is the advantage to a plant of closed stomata where water is in short supply? What are the disadvantages? The closing of the stomata would prevent transpiration of water and minimize this loss if water was in short supply.

  2. Marked by a teacher

    Investigate which surface of a leaf loses more water by transpiration.

    3 star(s)

    * Spread the Vaseline as equally and thinly as possible because this will cut down the percentage error * Have two test leaves to check whether or not the test has been fair, one with Vaseline on both sides to check whether the leaf can still transpire or not, and

  1. Does Leaf Surface Area Affect the Rate of Transpiration in a Plant?

    Of the transpired water passing through a plant only 1% is used in the growth process. Transpiration also carries nutrients from the soil into the roots and carries them to various cells in the plant. I think that the rate of transpiration will increase in proportion to the surface area

  2. The effect of wind speed on the rate of transpiration.

    When the guard cells take in water, they become turgid but they cannot expand in diameter because the cellulose micro fibrils will not stretch. They therefore increase in length particularly along the thinner, outer walls. The outer walls stretch more than the inner walls, causing the cells to change shape and to form a gap between them.

  1. Effect of Surface Area on Transpiration

    The capillary tube is filled with a continuous supply of water. The stalk of the plant is submerged into the capillary tubing containing water, and the water uptake by the plant is measured by using an air bubble as a marker.

  2. Factors affecting the rate of transpiration

    When opening the stomata the cell becomes turgid, due to the inflate of water. The microfibrils tend to stop the cell increasing in diameter, so they can only expand by increasing in length opening a stoma. The rate of transpiration can be affected by certain environmental changes.

  1. How temperature affects the rate of photosynthesis.

    amount of difference between the individual values and of the values from the mean. Repeat Temperature (oC) Rate of O2 bubbles (mm3/min) Average rate of O2 bubbles (mm3/min) 1 40.21 2 35 52.28 47.58 3 50.27 The values are significantly different from each other with the maximum variance being 12.07 mm3/min (52.28 - 40.21=12.07).

  2. Germination lab _ siddharth nair

    A measuring cylinder should be used to measure the amount so that equal amounts can be added to all the samples. * Make sure that only 10 cress seeds are added to each sample. * All the solutions should have a concentration of 0.5mol/dm3 so that each plant receives the same amount of inorganic ions.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work