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

The effect of growth medium on duckweed growth

Extracts from this document...

Introduction

The effect of growth medium on duckweed growth Duckweed (Lemna minor) is a common plant that floats in water and is common to stagnant water such as ponds. According to Texas A&M University Duckweed is the smallest flowering plant on earth. It is thought duckweed helps to reduce pollution levels. Duckweed is quick growing new leaves. The plant undergoes asexual reproduction by splitting into two (or more) new plants. Characteristics Duckweed plants consist of between two or three leaves known as fronds; these fronds are commonly between 1/6th and 1/8th of an inch in length. Habitat Duckweeds grow in large colonies on the surface of calm water, and more than one species can grow in the same body of water. Warning Duckweed grows rapidly and can aggressively invade pods and bodies of water. It can disrupt marine ecosystems. If the Duckweed grows rapidly and covers the body of water it can prevent light from reaching plants that live on the bottom of the pond. This can then cause fish that feed on the plants to die. It can also reduce the levels of oxygen in the pond water. Benefits Duckweed plants do provide a habitat for micro invertebrates. Duckweed plants grow best in nitrogen rich environments. This is especially high in polluted ponds. ...read more.

Middle

The duckweed taken from the pond is of a proportionate size. That the samples have the same amount of leaflets. Risk assessment There is a risk of infectious diseases such as weil's disease from contaminated water supplies. It is therefore essential that precautions are taken when placing hands into the water. All open wounds on the hands should be covered and vinyl gloves warn when coming into contact. Also care must be taken when around ponds, ensure that no risks are taken to get hold of the duckweed. Results Day Treatment Distilled Water Tap Water With fertiliser Number of leaflets Number of leaflets Number of leaflets 1 2 Mean 1 2 Mean 1 2 mean 1 3 3 3 3 3 3 3 3 3 4 3 3 3 4 4 4 7 8 8 7 3 4 4 5 7 6 13 12 13 10 4 4 4 7 8 8 18 15 17 13 4 5 5 9 11 10 25 21 23 16 4 5 5 11 13 12 32 29 31 19 5 5 5 12 15 14 44 42 43 22 5 6 6 13 17 15 58 57 58 Table 1 shows the number of leaflets on each duckweed plant grown under different conditions Day Treatment Distilled Water ...read more.

Conclusion

No attempt was made to replace the loss fluid. This could then have had an effect on the growth of the plants. Before the experiment started I should have marked the meniscus of the water and then topped up the volume with distilled water. The health of the duckweed plants used was not investigated at the beginning of the experiment. Even though the duckweed was taken from the same area of the pond, some of the samples could have been diseased. If I would have had time I could of investigated this by growing all of the duckweed in nutrient rich water for a few weeks before replacing them in the new mediums. This would have meant all of the samples would have been healthy and disease free. I also noticed that to the end of the experiment algae was growing in the tap water and fertiliser samples. This could have some effect on the rate of plant growth. To prevent this, the water could have been boiled and cooled before adding in the plant. ?? ?? ?? ?? This document was downloaded from Coursework.Info - The UK's Coursework Database - http://www.coursework.info/ This document was downloaded from Coursework.Info - The UK's Coursework Database - http://www.coursework.info/ This document was downloaded from Coursework.Info - The UK's Coursework Database - http://www.coursework.info/ This document was downloaded from Coursework.Info - The UK's Coursework Database - http://www.coursework.info/ ...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

    Advantages and disadvantages of fertiliser.

    by the microbes in the soil. 2) A garden may manually add synthetic fertilizer (e.g. man-made fertilizer) to the plants. When the fertilizer comes in contact with water, the materials dissolve and the fertilizer molecules are released. This process does not require microbes to break down the waste material like in the example above, so it often acts faster.

  2. Discuss the various adaptations of vertebrates that enable them to live in marine conditions.

    Maintain orientation and steer the body. The major adaptation noted by all truly marine vertebrates is the use of fins to control pitch roll and yaw in the aqueous environment. This has been developed in conjunction with the movement of the centre of buoyancy near the centre of gravity to prevent pivoting unintentionally when manoeuvring.

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

    In highly acid soils, aluminium and manganese can become more available and more toxic to the plant. Also at low pH values, calcium, phosphorus and magnesium are less available to the plant. At pH values of 6.5 and above, phosphorus and most of the micronutrients become less available.

  2. Absorption Spectrum of Chlorophyll.

    Role of the Solvent in the Extraction Process The choice of the solvent is a critical step in the extraction process. Chlorophylls being planar organic compounds, are expected to be well solvated by acetone, which is a polar organic molecule.

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

    Moreover if the ivy leaf covers more than half the square it will be counted as one. If it covers less than half the square it will not be counted at all. This is a much more accurate method compared to measuring just the length of the ivy leaf, from tip of leaf to steam using a cm ruler.

  2. Water and Mineral Nutrition in Plants

    When water is absorbed by a guard cell, it swells, stretching the cell. The thicker inner wall does not stretch so the rest of the cell gets distorted. This distortion of the pair of guard cells makes a shape which causes a gap between the guard cell pair's inner walls.

  1. The effects of organic effluent from the seweage on the biodiversty in a freshwater ...

    2.13 2.12 2.11 2.10 2.09 2.09 2.08 2.07 2.07 2.06 2.06 2.04 2.02 2.00 1.96 2.94 2.92 2.90 2.88 2.86 2.85 2.83 2.82 2.81 2.80 2.80 2.75 2.70 2.66 2.58 SOURCE: Maths for Advanced Biology By Alan Cadogan Robin Sutton PUBLISHER: Nelson Graphs: By looking at the graphs drawn above some solid interpretations can be made.

  2. Experiment Report on Best Fertilisers

    Remember to fill in the table every week for six weeks. Do the same thing with the camera, take a photo of the plant growth for referencing. Step 10 Add a second round of fertilizer on the fourth week after first signs of germination to ensure that the fertilizer placed before hasn?t disappeared.

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