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

Comparing the growth of pea plants grown in the light and in the dark

Extracts from this document...


Biology Coursework by Duncan Garnett Experiment 1 - Comparing the growth of pea plants grown in the light and in the dark Aim: To compare the vertical growth and weight gain of pea plants grown in the light and in the dark. Background Knowledge: Photosynthesis forms the basis for this experiment. This is the process by which a plant makes food for itself from the raw materials around it. The energy needed for photosynthesis comes from sunlight, which is the variable for this experiment. The substance that absorbs sunlight is chlorophyll, which is mainly contained in chloroplasts. This energy is used to convert carbon dioxide (CO2) and water into sugars. This conversion creates the waste product oxygen, which is used by humans for breathing. Without being able to photosynthesise plants will stop growing and die. In a plant growing in the dark the chlorophyll will slowly be destroyed causing them to use their food reserves. Once the reserves have been used the plant will die. This is what happens in plants that are not grown in sunlight. Etiolation is a phenomenon that occurs in plants not being grown in sunlight, whereby the stem of the plant rapidly elongates to increase the probability of the plant finding light. ...read more.


* After 3 weeks of growing each plant was removed from the pot and the soil was cleared from the roots. The roots were then washed and the plants were put into envelopes for a week to dry. * Once completely dried the plants were removed from their envelopes and weighed, with their weights being recorded in a table. Results: Plant Heights in Centimetres (cm) 19 / 6 / 02 26 / 6 / 02 3 / 7 / 02 Increase from 19 / 6 / 02 Light - Pot 1 18.0 24.5 25.2 7.2 Pot 2 16.0 25.9 26.5 10.5 Pot 3 12.0 32.4 25.4 13.4 Pot 4 12.1 16.0 16.7 4.6 Pot 5 13.1 20.1 18.2 5.1 Pot 6 8.0 9.0 9.5 1.5 Total 79.2 127.9 121.5 42.3 Mean 13.2 21.3 20.3 7.1 Dark - Pot 7 18.0 18.2 16.5 -1.5 Pot 8 17.8 19.0 13.5 -4.3 Pot 9 - - - - Pot 10 17.0 17.0 17.4 0.4 Pot 11 12.3 13.0 11.1 -1.2 Pot 12 - - - - Total 65.1 67.2 58.5 -6.6 Mean 16.3 16.8 14.6 -1.7 Dry Weight of Plants in grams (g) ...read more.


Pot 5 also showed a slight decrease in height over the 3rd week of the experiment but this is more likely caused by leaf drop-off or growth beneath the surface of the soil rather than above. In terms of weight, pot 11, which was the shortest of the surviving plants in the dark was the heaviest of those grown in the dark, but this may well be due to extensive root growth rather than growth of stems and leaves. The main improvement I would make to this experiment would be to increase the amount of results obtained in the experiment, in order to draw more accurate averages and more concrete conclusions. This would include using more plants in both the light and the dark, recording growth everyday to compare the point at which plants in the light grow faster and also I would lengthen the experiment to compare the flowering and pea production of plants under different light conditions. Another improvement would be to compare growth under different light intensities, in order to determine the ideal intensity of light in which to grow plants. However this would require further equipment and more controlled environments to implement and is not possible on the available scale. ...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. Mangrove Soil Analysis

    Conclusion: The different sedimentary percentages analysed in this experiment are responsible for the individual flora species that grow in some areas but not in others. This variation in plant types is important to provide different habitats and food sources for Australian wildlife and marine species.

  2. Investigating the growth of Lemna (Duckweed)

    THE PLAN: I will have a choice of eight different solutions in my investigation, seven of which contain a deficiency of one of the nutrients explained in the introduction. The eighth solution is a complete solution which includes: Calcium, Nitrogen, Potassium, Phosphate, Magnesium, Sulphur / Sulphates, Iron, Sodium and micronutrients.

  1. Compare the effect of heavy and light oil on terrestrial plants.

    After days or weeks, some heavy oils will harden, becoming very like an asphalt road surface. In this hardened state, heavy oils will probably not harm animals or plants that come in contact with them. In between light and heavy oils are many other oils, which would be "medium oils"

  2. The purpose of this investigation was to determine what effects different pH levels, more ...

    How the plant uses its energy depends on the developmental stage of the plant and on environmental conditions (Edward. B Rayburn, 1993). However the level of pH in the plant can have detrimental effects on photosynthesis. The pH levels effects the enzymes in the cells of the plant.

  1. In this investigation the effect of nitrate concentration on the growth of plants will ...

    Cambridge advanced sciences biology 1 page 59. If the energy available from ATP is limited, then the rate of active transport is decreased and the transport molecules in the cell membrane will not be working to their full potential. The large numbers of very fine hairs on the root thus

  2. Water and Mineral Nutrition in Plants

    At the same time water is lost through the stomata, via transpiration. The intercellular spaces of plant tissues are near 100% humidity, and the stomata are openings into the environment, which is usually not at 100% humidity. The diffusion gradient for water is from the leaf to the environment.

  1. Identify any differences that occurred, during the growth of hyacinths grown hydroponically, when different ...

    Bulbs are usually perennials. They have a period of growth and flowering, this is followed by a period of dormancy where they die back to ground level at the end of each growing season. The bulb can be categorized into five different types, which are: * True bulbs (tunicate and imbricate bulbs); * Corms; * Tubers; * Tuberous roots; * Rhizomes.

  2. Absorption Spectrum of Chlorophyll.

    The cylinder was then sealed using aluminum foil and adhesive tape and the eluent was allowed to move up the strip until the solvent front was near the top end of the paper (Zubrick, 1992).

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