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

Experimental Design Notes

Extracts from this document...

Introduction

Designing Your Own Experiment * Hypothesis: an explanation of an observation, written as a statement and testable. Can be based on previous knowledge * Variables o a characteristic or property capable of taking on a range of values and with the potential to affect things o Independent variables: variable set before starting the investigation o Dependent variables: variable that is measured during the investigation o Control variables: factor kept the same in the investigation * Parts of Experimental Method o Aim- purpose of the experiment o Hypothesis o Prediction o Method: physical steps required to test hypothesis and predictions * Things to consider * Materials needed * Variable * Sample size and replication of experiment * Experimental Design o Preliminary o Aim and hypothesis o Hypothesis and predictions are testable with resources available o Assumptions and variables * Awareness of assumptions that you are making in experiment * All variables are identified * Independent variable range has been set * Layout of experiment considered * Data Collection o Units for all variables have been identified o Amount of data to be collected has been identified o Consideration of how data will be analyzed o Method for systematically recording results * Repeat or Trials: investigation that is carried out again at a different time * Ensures experiment is reproducible and data is consistent * Treatments: well defined conditions applied to the sample o Specific and predetermined * Sample o subset of a whole used to estimate the values that might have been obtained if every individual was measured * Data o What is it going to look like? ...read more.

Middle

o Controlled experiments o Advantages o All factors other than the one hypo to be causing the effect can be kept constant o Comparative method Stats 2 * Reliability of the Mean o Variance is other measure of dispersion o 1 method calculate standard error * Standard Error o Allows for calculation of the 95 percent confidence interval o CI used to indicate relativity of an estimate o Degrees of freedom = n-1 o Calculated 955 of it can be plotted as error bars on a graph o Smaller CI more reliable the data staminate o Determines if there's a significant difference between sets of data * T-test o Only valid for certain situations o 2 group tests o Only have 2 samples to compare o Assumptions o Normal and not skewed distribution o SD for both samples is similar * Null hypothesis- the hypothesis of no difference or no effect * Probability that chance alone could make a difference have an effect * 5% = difference is due to chance 5% of the time * Degree of freedom = sum of total number of sample sizes of both groups * Steps o Calculate degree of freedom o V1 + V2 -1 = DF o Look at t values and match degree of freedom now with t value column o Values lie between 1 and 5 percent o Reject null hypothesis when P is 5 or less Microscopy o History o 1st century Ad glass as invented, Roman observed it and tested o Experimented with different designs o Thick in ...read more.

Conclusion

begin developing * Germination o Beginning of growth o Growth in a seed calls it a seedling o Process where the seed begins to grow * Seed Germination Dependency o Internal and external o Water o Temperature o Oxygen o Light * Start of Germination o Begins with water- called imbibitions o Seed takes up water, undergoes metabolic changes o Activates bio chemical process resulting in protein synthesis o Oxygen = seed metabolism and energy production o Seeds that are waterlogged or buried too deeply in soil won't get enough oxygen needed * Steps of Germination o Seed gets water, seed coat bursts o Chemical energy provides the energy needed for the embryo to enlarge and push out of the seed coat o Tip of root comes out first and anchors plant and lets plan absorb minerals and water form soil * Plant Vocab o Cotyledon: embryonic leaf inside the seed o Monocotyledon: one of two major groups of plants has only 1 cotyledon ex onions corn lilies o Diacotyledon: other major group of plants, 2 cotyledons, beans, castor oil plant * Monocot Germination o Primary root pierces seed coat and grows downward o Primary leaf grows up and is protected by the coleptile, hallow cylindrical structure o When the seedling is above round the coleptile stops growing * Dicot Germination o As embryo grows seeds out shoot called a radical o Radical becomes primary root and grows o Hypocotyls then emerges and lifts grouping tip o With light, hypocotyls straightens and cotyledons spread apart to expose the primary leaves ...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. Marked by a teacher

    Neurology and Behaviour. Focus question: Is there an increase in the perception and ...

    5 star(s)

    This particular experiment however has a high standard deviation among the results for both male and female disgust responses. As such the unreliability and inaccuracy of the data is inadequate in order to propose a theory regarding the gender differences in disgust responses.

  2. Ecology Design IA

    it's inclination to come out - Data to be recorded under same to similar weather conditions (therefore, a day forecast for scattered showers is not suitable as data recorded when raining will be different to data recorded when not) - Cannot be controlled, so therefore will be measured Placement -

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

    5: The volume of oxygen consumption in each 1.0 ml pipettes in ice water. The differences are calculated by subtracting final value from the initial value. The actual differences are calculated by subtracting the differences in control from the differences in germinating/non-germinating seeds.

  2. Transpiration Investigation

    99.7 97.0 98.3 1299 967 1133 180 99.6 97.0 98.3 1302 985 1143 190 99.5 96.9 98.2 1321 979 1150 200 99.5 96.8 98.2 1321 979 1150 210 99.5 96.8 98.1 1324 959 1141 220 99.4 96.7 98.1 1318 1000 1159 230 99.4 96.6 98.0 1315 953 1134 240 99.4

  1. The Effects of Salinity on Wheat Germination

    Germination An observation will be made as to whether the seed is in any way visually changed with the appearance of a shoot and the day on which this happens will be noted. Height Each plant will be measured after germination using a 30cm ruler with a precision of �1mm.

  2. Investigating the Probability Associated with Genealogy

    The partners of the F2 and F3 generations were selected in order to elucidate an array of results. Image II: Punnett Square of Nose Size (Both parents are homozygous) The image below illustrates the probability involved in the process of determining the genotype of offspring.

  1. Investigating the Effects of Salt on Seed Germination

    kind of graph to use to display these results would be to create a line graph: Macintosh HD:Users:160161:Desktop:Screen Shot 2013-08-24 at 5.03.21 PM.png DISCUSSION Our results show a wide range of relationships between the data. For instance, the shape of our graph shows that as the concentration/percentage of NaCl increased, the percentage of seeds that germinated decreased.

  2. How does the salinity of water affect the germination of mung been seeds as ...

    The calculated standard deviation and error bars for the other two of my results (0.0 and 0.2) varied in size. As at 0, the error bar is very large (1SD is 2) this indicates that the values recorded for this percentage was less valid and some other factor may have been affecting the results.

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