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

Factors affecting the rate of transpiration

Extracts from this document...

Introduction

Biology Lab Design Factors affecting the rate of transpiration Elric Balrog Introduction There are several factors which can affect the rate transpiration of plants; these could either increase the rate of water uptake or decrease the rate of water uptake. These factors could be internal or external. In this investigation we will be looking at the external factors which affect the rate of respiration, such as temperature, light intensity... etc. Transpiration is known as the loss of water vapour through the stomata of the leaves. It is needed to keep the cells of the spongy and palisade mesophyll cells moist as this allows carbon dioxide to dissolve before diffusing into the cells for photosynthesis. A suction force is created on the column of water below it in the xylem when water is evaporated. The upwards force on the column of water created by transpiration and the downwards force due to gravity created a tension in the column of water. As there is a difference in the upwards pull, which is greater than the downwards pull, the column of water moves up the xylem. As the cohesion tension theory explains it, water molecules are polar, meaning that they stick to one another. ...read more.

Middle

thermometer 1 x 1 Balsam leafy shoot 1 x 1 beaker 1 x 1 candle 1 x 1 match box 1 x 1 30 cm ruler 1 x 2 syringe with needle 50 ml DCPIP 1 x 1 black polythene bag 1 x 1 rubber bung Method 1. The apparatus was set up as shown on the protocol diagram. 2. The conical filter flask was filled with water. 3. The leafy shoot was transferred from the water filled beaker to the sink and a slanting cut was made few centimeters above the last cut in water. 4. The shoot was fit into the bung of the flask under water and pushed in to make a tight fit. 5. The end of the rubber bung with wax was sealed using a candle and matches. 6. DCPIP, the indictor, was inserted into one end of the graduated capillary tube using a syringe. 7. The shoot was left to equilibrate for 5 minutes as it adjusts to its external conditions whilst regularly replacing the water taken up. 8. The time taken for the water to move 30 cm along the capillary tubes were measured every 2 minutes. ...read more.

Conclusion

The experiment took roughly about 3 hours 30 minutes to complete as the set up of the equipment took a lot of time as well as the preparation of the shoot and adjustments which had to be made to limit air loss from the rubber bung. An unbalance in the pressure between the potometer and the graduated capillary tube would disrupt cohesion tension in the shoot. Seeing as only 3 environmental conditions were tested, a broader understanding of the effect of external factors on the rate of water uptake by a leafy shoot would be possible if other conditions were tested for, such as humidity, increased light intensity and vaselining the upper and lower epidermises of the leaves. More readings over a longer period of time could have been taking to obtain more accurate average. Moreover, an estimate of the water loss per unit in leaf area could have been derived by measuring the volume of water lost and then removing all the leaves in order to determine the surface area. Overall, I would have preferred looking at more factors which could have influenced the rate of water uptake by the Balsam leafy shoot, but because of time restraints I could not do so. It was interesting to see how external factors affect the rate of transpiration in plants. ?? ?? ?? ?? IB Biology Lab Design Page 9 of 9 ...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. internal assessment rate of transpiration

    in SET C experiment for rate of transpiration of plant in different speed of wind with respect to time. Qualitative data: It was observed that mass of entire apparatus of every set of experiment shows decrease in mass. Data processing Rate of transpiration of plant (hibiscus can be calculated by

  2. Biology HL IA - Transpiration lab report

    As the plant takes up water, the amount of water in the measuring pipette decreases. This experiment results proved hypothesis that with decreasing area of leaves, the rate of transpiration would also decrease. Transpiration rate was calculated according to the volume of water taken by a plant and the decrease

  1. Factors Affecting the Rate of Photosynthesis Lab

    Solution Method: 1. Pour 4g of sodium hydrogen carbonate into a beaker and dissolve in 400mL of distilled water to make a solution 2. Snip the tip of the stem and the top of the branch of a leafy branch of elodea 3.

  2. Environmental Factors affecting plant growth

    Normally, with the presence of phosphorus, the roots of the plant flourish and it plays an important role in the ability of plants of better tolerance of soil born diseases. But its deficiency might lead to slow growing, weak and stunted plants that might be dark green with older leaves showing a purple pigmentation.

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

    The significance of transpiration is a plant continues to pulls up water from the soil whenever water leaves the leaf to operate photosynthesis and bring and spread minerals throughout the plant (Transpiration, 2009). What's more, evaporation of water takes up heat and cools the leaves.

  2. Sleep is a normal part of human life. Investigate the neurobiological basis of normal ...

    Some societies display a fragmented sleep pattern in which people sleep at all times of the day and night for shorter periods. In general, people sleep in a more concentrated burst through the night, going to sleep much later. Comparison of Physiological Changes during NREM and REM sleep Physiological Process

  1. Examine the correlation between soil moisture at different heights up the slope and the ...

    Apparatus: * Digital thermometer * Soil moisture probe * Soil PH probe * Inclinometer * Whirling Hydrometer * Anemometer * Metre Ruler * 30 metre measuring tape for transect * Bottle of water (for Whirling Hydrometer) * Pen and paper to record results * Towel/cloth (for cleaning soil moisture probe)

  2. Comparing the Sexy Sons Hypothesis and the Pathogen Avoidance Models Effects on Sexual Selection

    This study was helpful as previously stated, the purpose behind all life in an evolutionary perspective is to produce more offspring and the polyandrous lineage males were able to accomplish that goal. A more complete analysis was done in 2013 by Adam Nelson and 8 other researchers.

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