• 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

    Experiment 2 Soil Permeability: Aim: To observe the rate at which 50mL of water passes through different samples of saturated soil and mud. Prediction: I predict that it will take the longest amount of time for 50mL of water to pass through the Outer Zone Mud.

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

    3.5 2.8 2.3 3.1 2.3 3.7 4.0 3.1 8.1 7.1 12.9 8.0 6.1 6.7 7.0 9.0 2.5 5.2 Leaf Number Count 2 2 2 2 2 2 2 2 2 3 4 4 3 3 2 2 1 1 Distance Between Nodes Stem Height Compared to Actual Height Table 3:

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

    Cambridge sciences biology 1 page 255. Preliminary study To find out what growing medium I am going to use for my investigation, I decided to do a study to see in what sort of growing medium my seeds will grow better in.

  2. Water and Mineral Nutrition in Plants

    and H2O is maintained within guard cells that varies from daytime to nighttime. In contrast to other epidermal cells, guard cells contain chloroplasts, and the process of photosynthesis is used to maintain turgor when stomata are open. Daytime Water and Mineral Nutrition in Plants We have just concluded a series

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

    Instead, the threat from heavy oils comes from their ability to smother organisms. Also, if heavy oils get onto the feathers of birds, the birds may die of hypothermia (they lose the ability to keep themselves warm). We observe the same effect if sea otters become oiled.

  2. 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.

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