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

Testing the effect of characteristics of leaves on the transpiration rate of * Rubiaceae, Verbenaceae, Oleaceae, and Rutaceae

Extracts from this document...

Introduction

Practical Number 10: Testing the effect of characteristics of leaves on the transpiration rate of * Rubiaceae, Verbenaceae, Oleaceae, and Rutaceae Introduction There is significant difference between plants and animals. It is generally a plant that produces its own food while an animal has to consume other organisms whether plants or other animals. Plants thus can be classified as autotrophs and primary producers in trophic levels. Plants undergo special process called photosynthesis to produce their own food and nutrients. In other words, light energy is converted into chemical energy useful for plants. They require carbon dioxide from the air and water from the ground. Additionally, the light from the sun and pigments like chlorophyll in green plants are also essential for reaction to take place. Then products for photosynthesis are glucose and oxygen. 6CO2 + 6H2O � C6H12O6 + 6O2 The importance of sunlight is that it is composed of a wide range of visible wavelengths. It is thus white light. White light is the mixture of all colors from short-wavelength red to longer-wavelength violet (Clegg, 2007). The relationship between sunlight and chlorophyll is that the structure of chlorophyll allows it to absorb some colors of the light and reflect the rest. As chlorophyll is green pigment in green plants, it, hit by white light, reflects only green light into human eyes while absorbing the rest of red and blue light (Clegg, 2007). Therefore, green plants look green to humans. Different pigments for different plants work the same. They absorb certain colors of light and reflect specific color. The reflected color of light determines the color of plants. Then what is the role of absorbed light? Some of light energy absorbed by chlorophyll is used to initiate photosynthesis. This is reason for the need of presence of sunlight during photosynthesis, especially the first step of the process. The first stage is called photolysis. ...read more.

Middle

What is more, wet branch slowed down transpiration rate. In other words, the first trial with dry branch had the fastest transpiration rate in a minute, compared to the rest of four trials. The insertion of branch into a rubber tubing was not always perfect. Thus, some water leaked from the crack between two. Though for the solution to that, vaseline was used, it was not that helpful. *Rubiaceae had spider nest on its surface of leaf. This somehow would have effect on transpiration rate because the process happens at the surface of leaves. The surface hidden under the nest would not have transpired as much. In fact, as time and trial goes, the skill of removing air bubble out improved. For the *Oleaceae, it was the first time to do experiment. It took much more time and had so various values than the last experiment was conducted. The last experiment was for *Rubiaceae. Except for the outlier 1.6 due to only dry branch, all the trials were precise and close to each other. Graph 1: the volume of water uptake (cm3) per minute per m2 by four different species of plant (*Rubiaceae, Verbenaceae, Oleaceae, and Rutaceae) Note: Error bars- data range Each mean is drawn in bar graphs, and the highest and lowest transpiration rate result for each plant is shown around it. Conclusion As mentioned in hypothesis, different species have different transpiration rate from each other. This can be proven by the data above clearly in Graph 1. The plant from Rubiaceae family took 0.7639 mL of water per minute per m� while 0.9512 mL was absorbed for Verbenaceae, 0.2678 mL for Oleaceae, and 0.1297 mL for Rutaceae according to Table 3. This is because all four species have different leaves. Of all features of leaves having effect on transpiration, the thickness of cuticles and stomatal complex are essential. Cuticles are hydrophobic waxy layers on the surface of plant and thus make water to move not easily through leaves (Transpiration, n.d.). ...read more.

Conclusion

Since the syringe can be detach from the potometer, it is possible to pull water up to the end and push the plunger back all the way to the other end to remove all air bubbles. Then fill the syringe up with water again and connect it to the three-way tap. Now water from the syringe would get rid of all air bubbles stuck in the passage when the tap is adjusted properly. In regards to the error of wet and dry state of branch and leaves, it seems the best way to just wait until the wet branch dries. The paper towel to dry those would be helpful for reducing the waiting time. Similar to the method right above, it is important to eliminate any water, dust, or even spider nest out of the surface of plant. These blocked stomata and prevented transpiration from occurring at the spot. The matter of suitable insertion of branch into a rubber tubing could be resolved by having different size of rubber tubings, cutting the branch at the same thickness as the rubber tubing. As temporary expedient, vaseline can be used. This will prevent the leaking of water from the crack between the branch and rubber tubing. The next step for improved laboratory is to repeat as much as possible. As long as biology is concerned, variations are inevitable. Just to decrease the variations, size of error bars, and standard deviation, many repetitions are required. The more there are repetitions, the greater possibility there is that the results get closer to the expected outcome. For future research, more than four families of plant species can be data range, which would give more information. Since this laboratory experiment is quite superficial in that it only identifies the differences in transpiration rate, deeper consideration is required on how the differences come from. It would be better not only to check the appearance of leaves but also the quantitative data for example like the thickness of waxy cuticles and stomatal size as in other experiments done by others. ...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 HL IA - Transpiration lab report

    Area of leaves provided (m2, �0,005) Transpiration rate (mL/m2min1) All leaves 0,11250 0,02250 0,530 0,043 2/3 of leaves 0,07625 0,01525 0,376 0,041 1/3 of leaves 0,06125 0,01225 0,180 0,068 No leaves 0,02250 0,00450 0,000 0,000 Conclusion and evaluation A branch of maple was placed in the hole of the rubber bung and inserted into the water filled test tube.

  2. Experiment Colours of Light (Wavelength) absorbed by green plant

    Measuring cylinder 3 100 ml +0.1 ml 6. Glass rod 1 Standard size Nil 7. Test tube 2 Standard size Nil 8. Centrifuge 1 Standard size Nil 9. Centrifuge tubes 4 100 ml +0.05ml 10. Conical flask 1 Standard size Nil 11. Set of calorimeter 1 Standard size Nil 12.

  1. internal assessment rate of transpiration

    SET B Time taken, minutes (min) � 0.01 Mass of entire apparatus, Newton (N) � 0.05 Normal humidity of air in room condition Less humidity of air with present of Sodium bicarbonate Trial 1 Trial 2 Trial 1 Trial 2 0 0.82 0.70 0.84 0.80 15 0.82 0.70 0.84 0.80

  2. The effect of toliet cleaning products on E-coli ...

    1.2.0 Controlling variables 1.2.1 Controlling variables (table 1) Variable identified Type of variable Method for control Toilet cleaning product used Independent The effect of different toilet cleaning products on the depended variables shall be examined. These products shall include... -King white -Toilet duck cleaner -Home brand toilet cleaner -Harpic toilet cleaner With bleach and water as controls.

  1. biology extended essay - How different diets: vegetarian, vegan and a meat centered diet ...

    I still go to school even when I am sick I still go to school even when i am sick I still go to school even when i am sick I still go to school even when i am

  2. Ecology Open Investigation Does the geographic location affect the biotic and abiotic ...

    Each group should calculate their mean for each abiotic factor and summarise their findings of the organisms. In the end there should be 5 means. When calculating the t-value and standard deviation use the 5 means of Brown Lake and 18 Mile Swamp.

  1. bio lab - The Effect of Temperature (C) on the Rate of Diffusion in ...

    7) The stop watch (±0.5s) was stopped when the food coloring dissolved and spread evenly throughout the water. 8) The time was recorded. 9) Steps 1 to 8 were repeated with water temperatures of 80°C, 60°C, 40°C, 20°C and 0°C i) For 0C°, ice cubes were put in the 500ml beaker and steps from 2 to 8 were repeated.

  2. Plan for an experiment - How does temperature affect the rate of photosynthesis?

    I also need to make sure that light intensity is in excess for this experiment, so that it doesn?t become a limiting factor. Therefore, I will be using a bright light 20cm away from the photosynthometer for each condition. As the bulb produces heat energy as well as light energy, this could also alter the results of my investigation.

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