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

Biology HL IA - Transpiration lab report

Extracts from this document...


Biology HL Candidate name: Ieva Drulyte Date: ___________________ Investigation into the transpiration rate of maple dependency on the area of leaves DCP, CE Introduction Transpiration is the evaporation of water particles from plant surfaces, especially from the surface openings, or stomata, on leaves. Stomatal transpiration accounts for most of the water loss by a plant, but some direct evaporation also takes place through the surfaces of the epidermal cells of the leaves. The amount of water given off depends somewhat upon how much water the roots of the plant have absorbed. It also depends upon such environmental conditions as sunlight, humidity, winds and temperature. A plant should not be transplanted in full sunshine because it may lose too much water and wilt before the damaged roots can supply enough water. Transpiration occurs as the sun warms the water inside the blade. The warming changes much of the water into water vapor. This gas can then escape through the stomata. Transpiration helps cool the inside of the leaf because the escaping vapor has absorbed heat. Design Aim: to investigate the effect of altering the leaves area on the rate of transpiration of Acer (Maple). Hypothesis: with decreasing area of leaves provided, the rate of transpiration would also decrease as transpiration occurs through stomata which are located commonly on the lower epidermis of leaves. ...read more.


of leaves 0,06 0,065 0,060 0,060 0,060 0,061 0,00224 No leaves 0,02 0,025 0,025 0,020 0,020 0,022 0,00274 In order to found transpiration rate per unit of surface area of leave, leaves, which were cut during every reduction of total surface area of leaves of a branch, were scanned and their surface area was calculated using a computer program ImageJ. Results were: area of first third - 153722 mm2; second third - 196203 mm2; last third - 179602 mm2. Hence, the surface area of leaves provided at every step was calculated by subtracting results above from the total surface area of three thirds of leaves. For example: Area of leaves after first reduction = total area - first third = (153722+196203+179602) - 153722 � 2/3 of leaves = 375805 mm2 = 0,376 m2. When the surface area of leaves was calculated, the rate of transpiration was found for every surface area of leaves tested by dividing average amount of water transpired per 1 min to the surface area of leaves in that step. Table 3 Processed data; transpiration rates: mL/min and mL/m2min1. Area of leaves Average amount of H20 transpired per 5 min (mL, �0,005) Average amount of H20 transpired per 1 min (mL, �0,005) ...read more.


However, one should be very careful not to harm leaves, hence, their xylems. Third, the results that transpiration at some level occurred even when all leaves were cut might come from inappropriate length of periods for which the plant was left to rest. A method improvement would be to measure a volume absorbed in every 10 minutes for an hour minimum and to perform an experiment continuously a few days. Finally, the method could be discussed at terms of precision and accuracy. This includes already mentioned aspect of counting area of surface of leaves and, what's more, raw data recording. As a pipette taken was only of 1 mL capacity, sometimes it was really hard to decide the exact amount of water absorbed. Pipette with smaller graduations should be used, however, plant would transpire water from pipette more quickly and this would lead to the re-filling the mechanism, which could result in the errors in the results as well. As these are so called minor improvements for the method of investigation, a few suggestions could be made for other possible experimental designs, for example, more types of plants could be used or other environmental conditions such as temperature or humidity could be altered together with the surface area of leaves in order to investigate more precisely the effects on transpiration rate. ?? ?? ?? ?? 1 ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our International Baccalaureate Biology 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 International Baccalaureate Biology essays

  1. Biology IA - Investigation of the relationship between surface area and volume using different ...

    Conclusion and evaluation The table 1 indicates that the rate of diffusion into 2% agar cubes does not depend on their size; no matter what was the size of the cube, NaOH travelled 0.5 centimeters per 10 minutes, which means the rate is 0.05cm/min.

  2. Factors affecting the rate of transpiration

    This will enhance the accuracy of our experiment and allow the plant to equilibrate with external conditions. A stopwatch is used to monitor the time interval from the start of the experiment to the end. The leafy shoot is first left to equilibrate for about 1 minute and then distance moved over two minute intervals are counted.

  1. Biology HL IA - Photosynthesis of elodea lab report

    Room temperature (~20�C); changes, if any, will be observed by using water thermometer and immediately reduced by conditioning. Type of plant Different plants have different rates of photosynthesis. Same plant will be used during all trials, Elodea Canadensis. Size of plant cm Larger plant would be able to produce more

  2. Biology IA - Paper Chromotography lab report

    Hence nettle could grow and photosynthesize in different wavelength light. The chart 1 implies that highest retardation factor is of the pigment carotene (0.94) and the lowest - of the pigment chlorophyll b (0.4). The approximate values differ from original ones only very little; therefore, it could be presumed that experiment was successful.

  1. In this extended essay I am looking at the effect of different kind of ...

    26.3 13 29.2 28.3 27.0 27.4 14 30.0 29.1 27.9 28.3 Conclusion: Different types of music do affect the growth of the plant in different manner. I checked this out by performing an experiment. In this experiment, I took 20 beans seed and split them into 4 parts.

  2. internal assessment rate of transpiration

    finding the average changes in mass of entire apparatus with respect to time by using formula: Since the mass of entire apparatus is in Newton, it must be converted into grams. To convert it, we use the ratio: 1 Newton=100 grams.

  1. Testing the effect of characteristics of leaves on the transpiration rate of * ...

    This transpiration rate is as influenced by a number of factors as is photosynthesis. The factors involve temperature, light intensity, humidity, soil water and so on. This laboratory would like to focus on different species of plants. Research question How does the different species of plants (Rubiaceae, Verbenaceae, Oleaceae, Rutaceae)

  2. Biology- Extended essay. For this research, I investigated the effects of DDT and ...

    This is why each fish was tested only once and then placed into a fresh fish tank. In the first investigation carried out, the 25 fishes were placed under different concentration of the created DDT solution and there opercular response was observed.

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