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

COMPARATIVE INVESTIGATION LAB ON LICHENS

Extracts from this document...

Introduction

COMPARATIVE INVESTIGATION LAB ON LICHENS Design Research Question: Is there a significant difference calculated by the t-test to show that the percentage coverage of lichens found on the north side of the trees after one meter from the base of the tree be affected by the tree being either in the shaded or the sunny area? Variables: Dependent variable: - the number of lichens found on the trees. Independent variable: - trees found in the shaded areas and trees found in the sunny areas. Constant variable: - lichens found on the North side of the tress - lichens found after one meter from the base of every tree - the altitude at which the trees are looked at - the same soil type for all the trees - the surface of the trees not being too rough and very similar - the humidity of the area from where the trees are looked at - almost the same amount of sunlight reaching the trees in the sunny area - almost the same amount of sunlight reaching the trees in the shaded area - the amount of water available to the trees Hypothesis: Lichens produce their food from the sunlight with the help of its photosynthetic partner. It is more likely for lichens to grow on trees in large number in an area that has more sunlight compared to an area that is shaded. ...read more.

Middle

shaded area sx and sy represents the standard deviation of the two samples Calculations for the sunny area: Mean = x = ?x n Note: x - mean of the total number of squares covered by lichen in sunny area ?x - the total number of squares covered by lichen n - the number of samples x = 973 20 x = 48.65 Standard deviation = s�x = ?(x - x)� n - 1 Note: s�x - represents the standard deviation for the sunny area ?(x - x)� - represents the sum of the square of the difference between the number of squares filled by lichen and the mean of the squares filled n - the number of samples s�x = 20.24 Calculations for the shaded area: Mean = y = ?y n Note: y - mean of the total number of squares covered by lichen in shaded area ?y - the total number of squares covered by lichen n - the number of samples y = 314 20 y = 15.70 Standard deviation = s�y = ?(y - y)� n - 1 Note: s�y - represents the standard deviation for the shaded area ?(y - y)� - represents the sum of the square of the difference between the number of squares filled by lichen and the mean of the squares filled n - the number of samples s�y = 4.84 Difference between the mean of lichen cover in sunny and shaded area: Difference between the mean = [x - y] ...read more.

Conclusion

* The water content in the soil from where the trees grew could not be accurately known and so it was kept constant by just feeling the amount of moist in the soil, which is not very reliable. * The availability of sunlight cannot be exactly known and therefore after some observations, trees were chosen that had about the same amount of sunlight available. Improvements: * The ground from where a meter is measured should be flat, and if it is not a flat land, then clear out the area without damaging the environment or use another side of the tree. * An electronic equipment (i.e. an electric compass) should be used if available to find the exact point of direction looking for on the tree so as to control the variable as precisely as possible. * One should try and count the squares covered by lichen as accurately as possible so as to get the most reliable and precise answer as it is one of the most important points to be taken care of in this investigation. * The investigation would be better done and more exact answers would be obtained if other factors mentioned in the conclusion were also kept constant more accurately such as, the availability of water, temperature, side of the tree, humidity, altitude surface of the bark and the amount of sunlight available. * A repeat would defiantly give a more accurate and a reliable result especially for this experiment since counting the number of squares covered by lichen is the most important part and the whole conclusion is based on it. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our International Baccalaureate Biology 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 International Baccalaureate Biology essays

  1. Plant Tropism Lab

    13.67 29.02 33.07 33.41 41.41 58.78 Pencil pod black 11.09 27.87 42.06 28.11 40.17 50.22 Stringless green 16.83 27.46 22.89 34.14 43.84 63.05 Kidney - - - 7.07 52.92 29.05 Aspect 3: Presenting Processed Data: Graph 3.1 Graph 3.2 Graph 3.3 Graph 3.4 Graph 3.5 Make Inferences About Data: The

  2. Bio lab - Oxygen Consumption in germinating and non-germinating seeds

    Conclusion & Evaluation Conclusion: My hypothesis was that the germinating seeds that are in the cold or room temperature water will have higher rate of oxygen consumption than the non-germinating seeds. I also predicted that as the temperature of the water decreases, the rate of oxygen consumption will be slower as well.

  1. Pill Bug Lab

    9 mL of water were added to 30 mL of potting soil that was separated into three connected petri-dishes that were connected to an empty petri-dish. The bugs were allow to roam and the number of bugs in each petri-dish was recorded every minute.

  2. Ecology Open Investigation Does the geographic location affect the biotic and abiotic ...

    into water until the water level reached elbow height of the collector - The collector turned 360 degrees on one spot, while still scooping with the net - The sample was then poured onto the tray - 18 Mile Swamp is surrounded by high dunes, the swamp itself is steeply

  1. Biology Industrial Melanism of Peppered Moth Lab

    Data Processing Overview I have chosen to use the format of tables to display the data of the percentages of melanic and light-coloured moths left after each trial/generation on different coloured "tree bark". I have chosen the format of tables because it provides a clear understanding of the collected data

  2. Biology- Extended essay. For this research, I investigated the effects of DDT and ...

    After carrying out the procedure suggested for Investigation 1. I arrive at the following results. RESULT TABLE: EFFECT OF THE DIFFERENT CONCENTRATIONS OF DDT ON THE OPERCULAR MOVEMENT OF CIRRHINUS CIRRHOSUS Doses of DDT/ppm Beaker: Opercular movement/min Mean opercular movement/min AVG S.D Mean of S.D (fish) First minute Second minute Third minute Fourth minute Fifth minute CONTROL A 146

  1. Osmosis Lab

    Each beaker was filled with 500ml of distilled water. Some of our "initial mass" measurements don't show the figure 10 grams, as there may have been some very little water loss or gain during the process of making the cellulose bags. Cell Size All our "cells" were cut and made at the same size.

  2. Enzyme Lab

    = amount of water added to the value ? Dependent Variable The rate of enzyme-catalyzed reaction will be observed by measuring how much water is displaced from the 100ml graduated cylinder. This measurement will determine how the concentration of the substrate affects the rate of enzyme-catalyzed reaction.

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