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

Investigation to find out whether plants need nitrate, phosphate and potassium.

Extracts from this document...


Biology coursework - Minerals Aim We are carrying out an investigation to find out whether plants need nitrate, phosphate and potassium. Key Factors Things to keep the same (to make a it a fair test) * Make sure the right amounts of minerals are added to the distilled water in each beaker otherwise it will not be a fair test. This will ensure the only outcome of the experiment can be based on the deficiencies of the minerals. * Make sure the seedlings are provided with the same amount of light. It would not be a fair test if three seedlings were left in the shade and another nine on the windowsill. Therefore if some seedlings are left in an area with less light it can come out as a limiting factor, affecting the outcome of the whole experiment. * The environment in which the seedlings are left in can affect the experiment, e.g. if the seedlings are left in separate rooms it could affect the outcome of the experiment because one room may be hotter than another. Therefore to ensure a fair test we must give all the seedlings equal opportunities by providing the same temperature. * The black paper has to be wrapped accurately around the boiling tube so light cannot pass through. ...read more.


Apparatus * Twelve boiling tubes * Black paper * Cotton wool * Tube * Seedlings * Distilled water * Minerals Diagram Method * Collect apparatus as shown in the diagram. * Add the minerals to the distilled water. So in three tubes add all minerals1 apart from nitrate. In the next three add all the minerals with the exception of potassium. In the final three tubes add all the minerals apart from phosphate. There will be a controlled experiment where the seedling will have a sufficient supply of all the required minerals2. * Put the seedlings inside the boiling tube and set as shown in the diagram-with the tube and cotton wool. * Place all twelve seedlings in the same room. * Blow air into the tube frequently so that the plant roots can respire. * Measure the roots, leaves and stems every week for six weeks. It would be advisable to mark one or two certain leaves and measure them every week for six weeks (like wise with the roots and stems). * Note anything you notice about the plant, e.g. whether the plant has stunted or whether the leaves have gone pale. Safety > Follow regular laboratory rules. Research Primary (Macro) ...read more.


Potassium increases photosynthesis, but without the aid of potassium the plant will not even photosynthesise at its normal rate because it lacks potassium. Potassium also activates enzymes and controls their reaction times. Enzymes are needed in various processes for plants, such as photosynthesis and respiration. In respiration the large molecules have to be broken down by enzymes and when they react, then the energy is released. The large molecules are broken down into smaller molecules by enzymes. However potassium activates enzymes, so without the aid of potassium the three plants cannot break down the larger molecules taken in from the roots. Therefore the three plants will find it difficult to carry out many processes. Without potassium plants are very prone to disease. The first sign of disease shows up in the plants because the leaves will have dead spots. Without potassium the immune system of the plant will be weak and there will be drastic changes, such as pale leaves. The plant in the controlled experiment will be healthy because it will be supplied with all the vital nutrients including the primary nutrients- nitrogen, phosphorus and potassium (N, P, K). 1 There are fourteen minerals with the exception of the primary nutrients (nitrate, phosphate and potassium). 2 The controlled experiment will have all fifteen minerals. This is the only experiment with all the minerals. ?? ?? ?? ?? ...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 investigation into the effect of a germination inhibitor on the germination of seeds.

    3 star(s)

    2 E 48.1 2.62 0.29 5.8 5.8 5.8 x2 = ? D2 = 48.1 + 2.62 + 0.29 + 5.8 + 5.8 + 5.8 = 68.40 E This result is also not on the probability table, so it too rejects the null hypothesis and accepts the hypothesis.

  2. Flowering plants Investigation

    Flowering plants have a green pigment called chlorophyll which can absorb some of these light rays and use their energy to build up the simple sugar, glucose , from carbon dioxide and water. The light energy is trapped as chemical energy in the glucose molecule.

  1. An Investigation into Water Loss from Plants.

    This is because leaves weighing different amounts will have different amounts of water to lose.

  2. 'A study into the effect of phosphate concentrations on the growth of phytoplankton'.

    Once I had returned to the lab I filtered the water again and then washed the contents out with distilled water in order to create a stronger concentration of the solution. This solution was labelled and covered with tinfoil in order to prevent contamination from other sources in the lab, and placed to the side.

  1. Investigating the growth of Lemna (Duckweed)

    But when the investigation progresses, the count of the Lemna will increase exponentially, i.e. very fast and so counting become inaccurate as it is hard to keep track of which individuals have been counted and which have not. At this stage, the logical method to use is the area covered

  2. How temperature affects the rate of photosynthesis.

    successful collisions ids greater, resulting in a larger increase in the rate of photosynthesis between higher temperatures like 15 oC and 25 oC and an even higher increase between 25 oC and 35 oC. The optimum temperature is the temperature at which the enzymes are working at their highest capacity.

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

    If the soil layer is thick, on the other hand the soil will have a greater capacity to hold water, before it is drained through the chalk. Pingoes are glacial features, which occur by the uplift of the land and subsequent collapse of a mound.

  2. Investigation into the effect of varying concentrations of potassium nitrate solution, on the germination ...

    This lowering of the activation energy increases the number of molecules which have enough energy to react. Therefore, more molecules react and more products can be formed. The diagram above shows the effect of temperature on an enzyme-controlled reaction. It demonstrates the importance of temperature in seed germination.

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