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

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

Extracts from this document...

Introduction

An experiment to investigate the water loss from leaves through stomata In the experiment I intend to find out which of the four leaves will lose the most water and why. Method For the experiment to be carried out the following materials will be needed: * Four leaves which approximately have the same mass and surface area * Petroleum jelly * String * Four paperclips * Two clamps * Electronic balance Four leaves were chosen with approximately the same mass and volume. Petroleum jelly was put on three of the four leaves using the finger. On leaf 1, petroleum jelly was smeared on both the upper side of the leaf and the also the bottom side of leaf. On leaf 2, petroleum jelly was then put on the upper side only. Petroleum jelly was then put on the underside of leaf 3. On leaf 4, the controlled leaf, no petroleum jelly was put on. The leaves were then weighed on an electro balance (the results were recorded in a table). The four leaves would then hang on a string, which were tied to the poles of two clamps. ...read more.

Middle

and then again at the end of the experiment. This will tell us the total amount of weight loss, which will give us an indication of how much water loss there has been. Results that have been taken must be reliable. Also all calculations that have been performed will also be done twice. This will reduce the chance of a mistake. Background Knowledge Water is lost through small pores found in the underside of the leaf called stomata. The water is lost through a process called Active Transpiration. The water turns into water vapour and then it diffuses into the air. It happens mainly inside the leaves in the cellulose wall. The stomata are open throughout the day to allow carbon dioxide to pass through (this lets water escape too). In order for the leaves to transpire the leaves will need to be in light at all times (otherwise the stomata would close up). Diagram Obtaining evidence To obtain evidence we weighed the leaves. This was done again after 24 hours for seven days. Then the original mass of the leaves was taken away from the mass of leaves at the end of the experiment. ...read more.

Conclusion

This may have happened because the leaves may have not have had the same amount of water in them at the beginning of the test. Also the leaves themselves may not have had equal surface areas. Also the amount of petroleum jelly may not have covered the whole leaf (this may have given unfair advantage to one of the leaves). The readings were not repeated when any of the values did not fit in with the pattern. The readings, which were taken, were far enough to make a firm conclusion. However the experiment could have improved. In the experiment the size and mass of the leaves were approximately the same but more accurate measurements could have been such as weighing the leaves at the start on an electro balance (before the petroleum jelly was added) to make sure the leaves had the same mass. Also the perimeter of the leave could have been measured to make sure the surface area was the same. To make the test more accurate it could've been done twice. Also when petroleum jelly was added there may have been gaps in between (so water vapour could have diffused), this should have been checked. To take the experiment further it could have been repeated with different specie of leaf to see if the results were the same. ...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

    An experiment to show how water loss in leaves can vary.

    4 star(s)

    * Using different leaf types could result in an unfair test due to the same principles as the leaf sizes. Prediction I think that covering the underside of the leaf will be the most effective method of preventing transpiration because I am almost certain that the stomata will be there since the majority of leaves do.

  2. An Investigation into Water Loss from Plants.

    If the results show that t is greater than or equal to the critical value then it is more likely down to scientific laws than chance. If it is less than the critical angle it is most likely down to chance and so the hypothesis is disregarded and therefore the null hypothesis accepted.

  1. The Loss of the Aral Sea

    Nearly 70% of the town's population have pre cancerous conditions; its annual death rate is 100/1000 - so it's easy to see that these predictions are not over exaggerated. During the last 10 - 15 years, kidney and liver diseases, especially cancers, have increased thirty to forty fold, arthritic diseases by sixty fold and chronic bronchitis by thirty fold.

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

    Apparatus 1. Tape Measure (50m) - needed to mark the area which is being used in the experiment. 2. Square quadrat - where the square quadrat is placed according to the coordinates chosen randomly, the ivy leaves present within the square quadrat will be used in the experiment.

  1. The aim of my particular experiment was to investigate into the possible existence of ...

    Water movement through a plant As transpiration takes place, water diffusing into the air spaces from the spongy mesophyll cells takes its place. This is turn sets up a concentration gradient across which water moves by osmosis out of the xylem cells and across the leaf.

  2. Heat loss in Emperor Penguins.

    44 40 42.0 16 41 43 39.5 41.2 17 40.5 42 36 39.5 18 39 41 34 38.0 19 38 40 33 37.0 20 37.5 39 32.5 36.3 Fig. Huddle I Experiment 1 Experiment 2 Experiment 3 Averages Time (seconds)

  1. Three separate experiments which are to be carried out to investigate a plant's unique ...

    * I predict that there will be the same number of stomata per square millimetre on each leaf. This is because the leaves are on the same plant, and so the genetics of the plant will determine how many stomata there are in a certain area.

  2. Investigating the amount of stomata on a variety of different sized leaves.

    that the younger leaf will not need near as many of stomata as the younger leaf as I think that transpiration is less important to a younger leaf. Method 1. First of all I am going to collect two leaves from the same plant.

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