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

Effect of Surface Area on Transpiration

Extracts from this document...

Introduction

Effect of Surface Area on Transpiration Most of the water entering a plant does so via the root hairs. It travels across the root cortex to the xylem, ascends in the xylem to the leaves and is lost by evaporation from the surface of the mesophyll cells before diffusing out through the stomata. This process is called transpiration, and the flow of water from the roots to the transpiring surfaces forms the transpiration stream.. Transpiration is the loss of water vapour from the surface of a plant, and may occur from: 1) stomata: by evaporation of water from cells and diffusion of the water vapour through stomata, the pours found in the epidermis of leaves and green stems (about 90%). 2) waxy cuticles: by evaporation from the outer walls of epidermal cells through the waxy cuticle covering the epidermis of leaves and stems (about 10%, varying with thickness of cuticle). The aim of this experiment is to find out how the surface area of a plants leaves effects transpiration. Equipment: Potometer(short rubber tubing, rubber bung, graduated capillary tube), small electric fan, stand and clamp, stop clock, Vaseline, leafy shoot ( laurel). ...read more.

Middle

Consequently, depending upon temperature and humidity, transpiration is faster on a windy day than in still air. The best conditions for a higher rate of transpiration are the same as those needed for drying washing on a line: a warm, dry, sunny, windy day. Fair Test A fan will be set 1meter away from the plant, and will supply the heat and wind needed to cause the plant to transpire, thus causing water uptake by the xylem of the stalk.. The strength of the fan will remain constant as will the distance that it is set apart from the plant. The light intensity and the humidity of the room will be kept constant as much as possible. The variable that will be changed Is the surface area of the plant. This will be done by starting with 10 leaves on the plant, and then after 2 minutes of the fan blowing on the plant, 2 will be removed. The water uptake for each number of leaves will be recorded, and two will be taken away every two minutes and the results recorded until there are no leaves left. ...read more.

Conclusion

The surface areas of the leaves were measured very accurately using graph paper which enabled me to measure to the nearest mm�. Vaseline was rubbed on the ends of stems after leaves had been removed, which enabled me to minimise water loss. In spite of this there are still factors which could have altered the results. The experiment was done by many people in the same room. After the fans where switched on the temperature in the room would have gradually increased, which in theory could cause transpiration to increase as the experiment went on. Also, it was impossible to make the fan blow on all leaves equally. It is inevitable that some leaves has more heat and wind on them than others. This could cause less transpiration is some leaves, than others. Further work: Another experiment that could be done can measure the transpiration rate through the waxy cuticles of the leaves. Using the same method as the main experiment, use 4 leaves. Measure the water uptake over 2 minutes, then coat the bottom layer of each leaf(lower epidermis) thoroughly, and again measure the water uptake. There should be less water uptake when the lower epidermis is covered in Vaseline. Then cover both the upper and lower epidermis in Vaseline and measure the water uptake. Again there should be considerably less water uptake. ...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

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

    3 star(s)

    would not make any significant differences since the results in this experiment show rough correlation but are not accurate enough to merit a pair of scales of greater accuracy. Also, weighing all the leaves simultaneously on different pairs of scales could very slightly alter the results because with conventional weighing

  2. Design and Carry out an investigation to see what effect light intensity has on ...

    Time in (secs) The rate of transpiration will be calculated by Rate = Distance traveled (mm) Time (seconds) This will result in the following graph Rate of Transpiration Light intensity (Lux) Within this planning section the accuracy and validity of the data has been discussed, and will now be further

  1. Factors affecting the rate of transpiration

    the water in the beaker, blotted with a paper towel, then replace into the water when an air bubble has entered the end of the tube. The air bubble is between 3 and 6 mm long. 6. Do not use Vaseline on the potometer in the hope that this will make a water-tight seal!

  2. Conducting an experiment to find out what effect the surface area has on the ...

    From the scientific knowledge, preliminary work and background research I have made the following prediction. Hypothesis: � The rate of water up take is directly proportional to the surface area of the leaves on the plant. As the surface area is reduced the time taken for the water to travel the stem over the same distance will increase.

  1. Measuring rate of water uptake by a leafy shoot

    the water uptake by making it slower than it otherwise would be. The addition of Vaseline is most affected when it is spread over the bottom of the leaf, hence, covering the stomata. The reason why this occurred is because, when the experiments were conducted under normal conditions, there was nothing preventing transpiration.

  2. The investigation is aiming to look at transpiration.

    In the same way as the symplast pathway, a water potential gradient between the xylem and the sub-stomatal airspaces exist. It is along this gradient that water passes. MOVEMENT IN XYLEM TO THE LEAVES Water taken up by the root hairs crosses the cortex and enters the xylem in the centre of the root.

  1. Investigation Into The Rate of Water Uptake By Transpiration.

    with water vapour so that no more can escape from the leaf. In these conditions, transpiration will slow down. In moving air, the water vapour will be swept away from the leaf as fast as it diffuses out. This will increase the rate of transpiration.

  2. The effects of organic effluent from the seweage on the biodiversty in a freshwater ...

    14. Temperature probes will be used to determine the temperature difference between the sites and hence determining the biodiversty.Sun is the main source of light for an ecosystem and hence the main source of heat. High heat capacity of water effectively buffers the temperature changes in aquatic habitats.

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