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

Investigation to find does light intensity affect the stomata density of leaves.

Extracts from this document...

Introduction

Investigation to find does light intensity affect the stomata density of leaves. Aim: To find out that does light intensity affect the stomata density of leaves. Leaf stomata are the main means of gas exchange in vascular plants. Stomata are small pores, typically on the undersides of leaves, which open or close under the control of a pair of banana-shaped cells called guard cells. When open, stomata allow carbon dioxide to enter the leaf for synthesis of glucose, and also allow for water, and free oxygen, to escape. In addition to opening and closing the stomata, plants may exert control over their gas exchange rates by varying stomata density in new leaves when they are produced. The more stomata per unit area the more carbon dioxide can be taken up, and the more water can be released. Thus, higher stomata density can greatly amplify the potential for behavioural control over water loss rate and carbon dioxide uptake. Prediction: I think that from the top section of the bush will have more stomata present. I think this is because light stimulates the stomata's to open, and at the top of the bush the leaves are receiving the most light. For photosynthesis to happen the plant needs sunlight and carbon dioxide, so there are more stomata present there to take in the carbon dioxide they need for photosynthesis. I think that at the bottom section of the bush there will be less stomata present, because there is less light reaching the leaves, so there ...read more.

Middle

I measured the light intensity using a luxmeter from the different sections of the bush, from where the leaves were taken from. So that I know how much light is received by the leaves in those sections. I did all the experiment in one day, so that it was a fair test, because then the weather would be the same, the condition for the leaves would be the same. The weather being different, more humid or windy does affect the stomatal density. I used clear nail varnish because the stomata get imprinted on it. I use the graticule in the eyepiece because it gives a measurement I could use to measure along the line to see how many stomata were present. To ensure that I counted the number of stomata accurately, I checked several times. Results: Below the table shows the results my group collected. Height (Cm) Light intensity (Lux) Average Light Intensity Stomata present along line of graticule Average number of Stomata present A B C 50 36 37 37 37 6 7 6 6 100 70 69 67 70 8 6 6 7 150 185 184 186 185 6 5 5 5 200 276 275 276 276 7 6 6 7 250 851 850 849 850 8 9 8 8 These are my second set of results: Height (Cm) Light intensity (Lux) Average Light Intensity Stomata present along line of graticule Average number of Stomata present A B C 50 88 87 89 88 6 7 6 6 100 250 251 ...read more.

Conclusion

That as you go into the higher sections of the bush, there will be more stomata present there because those leaves were receiving more light. Evaluation: I think the experiment worked well, because I think I obtained accurate results, my results matched my prediction. I think that the quality of my method and results was quite good. I think that my method was the best way of doing the experiment, it was reliable, and gave accurate results because it was accurate to what I had predicted. I think I had enough correct results to draw a conclusion because me two sets of results were very similar. I have got enough evidence from my results to get a clear picture of how light intensity affects the stomata density. I think that my results were quite accurate and reliable, but for my secondary source of results I don not think they were that reliable. There could be various reasons for why these results were very different to mine. The method they were using could be totally different to mine. Maybe the bush might be a bit thin from where they were taking leaves. Maybe they did not count accurately using the microscope to count the number of stomata along the line of the graticule. To improve the quality of my results, I would do the experiment a couple of more times and compare and see if they are similar or not. Another experiment that could be carried out to extend this work could be to see how temperature also affects the stomata on leaves. ...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. Peer reviewed

    An Investigation into the Effects that Different Light Intensities have on the Speed of ...

    5 star(s)

    slightly lower and if they had of been lower then the curve- shaped interpretation can no longer be applicable. Further work: If I was able to carry out further work on this investigation then I would like to spend more time trying to find a different method which would have avoided temperature from having an effect on my results.

  2. An experiment to investigate the water loss from leaves through stomata.

    In the result there are no patterns or trends. In the experiment I discovered that if petroleum jelly was put on the underside of the leaf, it would stop more water vapour escaping than if petroleum jelly was added to the top of the leaf or if none was put on at all.

  1. Are there more stomata per mm2 on old leaves or young leaves?

    Therefore, the number of stomata a leaf has per mm2 will remain constant throughout its existence, regardless of its age. Obtaining Results When I chose my three young leaves, I made sure that they were the smallest leaves I could find.

  2. How temperature affects the rate of photosynthesis.

    Although this would not have affected the rate of photosynthesis significantly. Ruler The ruler was accurate to 1mm. Therefore the lengths of the elodea too were accurate to 1mm. Same ruler was used throughout the experiment and therefore any risks of human errors because of change in ruler were minimised.

  1. The investigation is aiming to look at transpiration.

    RESULTS Table {1} to show the rate of transpiration in mesophytes using a range of different conditions. Conditions {Inhibitors} Time {Mins} Initial Volume {cm3} Final Volume {cm3} Average Volume {cm3} Average Volume Per unit Time {cm3min-1} Normal 5 2.3 0.0 3.6 1.2 1.3+1.2/2 = 1.25 1.25/5 = 0.25 Electric fan

  2. The aim of our investigation is to find out how the amount of light, ...

    Temperature- the optimum temperature is around 30 . Photosynthesis still works fine up to about 40 . But once you get much above 40 it slows down dramatically. Carbon dioxide- if paraffin is burnt in a greenhouse the carbon dioxide levels increase and so does the rate of photosynthesis- that increases growth.

  1. An Investigation into Species Diversity with distance along a Pingo.

    20 23 23 24 24 24 Number of species observation2 5 5 6 9 12 13 17 17 17 17 Number of species observation3 4 6 10 12 18 22 24 26 26 26 Number of species observation4 2 5 7 7 9 12 16 17 17 17 Number of

  2. Investigating the abiotic factors that affect the size of Ivy leaves in shaded and ...

    The Light-Independent Stage The light-independent reactions are known as the Calvin cycle. This is a cyclic reaction consisting of a series of small steps resulting in the reduction of carbon dioxide to bring about the synthesis of carbohydrates. NADPH and ATP from the light-dependent reactions provide the reducing power and the energy needed for the various steps.

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