LAB REPORT

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Seed Germination Experiment

Purpose:

To gain experience in:

  • Setting up experiment
  • Following directions in the form of experimental protocol
  • Share data collected
  • Making observations of an experiment
  • Writing up a lab report for a science course

In addition, students will be able to:

  • Have hands on experience in handling seeds
  • Observe what plants look like as the seed germinates by removing the seed coat
  • Dissect the seeds at the conclusion of the experiment

Experimental question:

The experiment investigates the effect of temperature on the time to germination of 3 different species of plants: maize, pea, and bean.

Experimental procedure:

Each student will be responsible for one replication of two different treatments:

  • high temperature
  • low temperature

Materials:

  • Seed packets of maize, pea and bean
  • 6 paper towels
  • 6 sandwich or 1-litre zipper bags

To begin the experiment:

  1. Remove the seeds from each packet and divide the seeds into groups of 15-20. You should have 6 groups of seeds. Two of each seed type.
  2. Fold the paper towel in half and again in half so they easily slide into the zipper bag.
  3. Dampen the paper towel so that it is wet but not dripping.
  4. Unfold the second fold of the paper towel and place the seeds neatly on bottom two layers of the towel
  5. Close the fold so the seeds are sitting in the middle of the bottom two layers of paper towel and the top two layers of paper towel
  6. Carefully slide the paper towel in the zipper bag
  7. Seal the zipper bag 95% of the way closed to allow a little air movement in and out of the bag
  8. Label each bag with the type of seed that is in the bag (Maize, Pea, Bean)
  9. Divide the bags into two sets of seed. Each set of seed should have 1 bag of each of the different species and the sets should be labeled as High Temperature or Low Temperature, label the bags with the appropriate label.

There should now be 6 bags with 3 bags for high temperature (one each: Maize, Pea, Bean) and 3 bags for low temperature (one each: Maize, Pea, Bean)

Imposing the treatments:

A household refrigerator will be used to impose the temperature treatments:

  • The high temperature seeds will be left at room temperature each day and only picked up and set back down each time the other set of seeds is moved.
  • The low temperature treatment will be transferred from room temperature to the refrigerator for 8-12 hours a day (overnight).

Each day:

  • Seeds should be checked to make sure they have adequate moisture. The paper towels should be damp and cool to the touch when at room temperature.
  • Seeds should be observed for germination
  • Once seeds begin to germinate students should remove the paper towels and seeds, observe the seeds and place them back into the bag. Recording the stage of germination each time
  • Move the cold temperature seeds from the room temperature into the refrigerator and then back out again. Each time the seeds are moved the room temperature seeds should be picked up and set back down.
  • Record the temperature experienced by the two treatments.

Calculating temperature:

For the purpose of this experiment, room temperature will be assumed to be 20oC and the refrigerator will be assumed to be 4oC. The room temperature seed will accumulate 20 temperature units each day. To calculate the temperature units accumulated by the cold temperature seed multiply the hours spent at room temperature by 20 and add that to the hours spent in the refrigerator multiplied by 4. Then divide that number by 24 to get the daily temperature units experienced by the cold treatment. This way if you forget to move the seeds for a few hours your data can still be useful to the group. See the formula below for more information.

Temperature Unit Calculation:

High temperature (hrs) x High temperature (°C) + Low temperature (hrs) x Low temp (°C)

24 (hrs)

The individual excel data sheet that you must fill out provides the first entry for you on day 1 and was calculated as follows:

Low Temperature Accumulation

(15 x 20) + (9×4)

= 14

24

For high temperature accumulation, remember that 20 units are accumulated per day and this is reflected in the data table.

Making and recording observations:

When seeds are being observed you can measure the different stages of germination and record the number of seeds in each stage of germination. Radical emergence, coleoptile or stem emergence, leaf emergence.

Fill in the data table with the number of seeds at each stage of emergence.

Once you have a completed the table you will need to submit this to the appropriate dropbox n CourseLink so we have a complete record of your experiment. You will also be asked to fill in the master data table on your MS Teams Lab Group file page.

The master data table will ask for:

  • Temperature units accumulated to reach 50 % germination of the High temperature treatment for each seed type
  • Temperature units accumulated to reach 50 % germination of the Low temperature treatment for each seed type
  • Days to reach 50 % germination of the High temperature treatment for each seed type
  • Days to reach 50 % germination of the Low temperature treatment for each seed type
  • Percent of seeds that germinated in the High Temperature treatment for each seed type
  • Percent of seeds that germinated in the Low Temperature treatment for each seed type

Lab report instructions are in another document.

 

 

What You Will Need

  • Three seed packets
  • Six 1L plastic bags
  • Six large paper towels (twelve small ones)

 

Step 1 – Divide the seed

  • Remove seeds and divide them into groups of 15-20
  • There should be six groups

 

Steps 3-5

Dampen paper towel Neatly place seeds in middle fold                 Close fold on seeds

 

 

Record your findings!!!

Making and Recording Observations

  • Seed germination
  • Growth stages of germination (radical emergence, coleoptile or stem emergence, leaf emergence)
  • The number of seeds in each growth stage

 

 

 

 

Reporting your data

  • Temperature units accumulated to reach 50 % germination of the High temperature treatment for each seed type
  • Temperature units accumulated to reach 50 % germination of the Low temperature treatment for each seed type
  • Days to reach 50 % germination of the High temperature treatment for each seed type
  • Days to reach 50 % germination of the Low temperature treatment for each seed type
  • Percent of seeds that germinated in the High Temperature treatment for each seed type
  • Percent of seeds that germinated in the Low

Temperature treatment for each seed type

 

 

Scientific Method

THE SCIENTIFIC METHOD

There are four basic steps of the scientific method:

  1. Ask a question/do background research/make an observation.
  2. Construct a hypothesis and experiment objective.
  3. Design and perform an experiment to test the hypothesis and analyze the results.
  4. Draw conclusions based on the results and the acceptance or rejection of the original hypothesis.

Hypothesis and Objective

A hypothesis is a tentative explanation to answer a question based on an observation(s). This is also called an educated guess. An objective is a short description of what you are going to do to investigate the question.

Experiment

Experiments are conducted to test a hypothesis. Ideally all experimental conditions remain the same for all treatment groups within an experiment except for one variable – the independent variable.

The independent variable is the one factor that you are changing. Usually in an experiment you alter one thing at a time. This makes measurements and interpretation of the data much easier. This is the variable you are purposely changing to see its effect on dependent variables.

The dependent variable(s) is the variable you observe, to see whether it is affected by your independent variable.

Data Analysis

Data analysis involves comparison of the results from the different treatment groups within the experiment. There are a great variety of types of statistical analyses but the most basic involves the descriptive statistics: the mean and variance. The mean, or average, is the sum of all the values divided by the number of values (sample size, n).

One also needs a measure of the variation, or the confidence, of the estimate of the mean. The best measure of this is called the standard error, which is a measure of the expected variation of the mean if the study were to be repeated. This can be abbreviated as se or sem; the latter is short for standard error of the mean. Sometimes a measure of the dispersion of the raw data may be presented; this is computed as the standard deviation. However, if means are being compared, it is preferable that the standard error of the mean estimate is presented.

These results are often presented either in a results table as mean  standard error or presented graphically in column graph form. For this assignment we will have you present the results in vertical bar graph format. For help in graphing in Microsoft excel refer to the graphing help link on Courselink.

Page | 19

Lab Report Instructions

LAB REPORT INSTRUCTIONS

Font: Times 12 pt Margins: 2.5 cm (1 inch). Portable document format (pdf)

Style: CSE Name-year. There are a number of heading styles that can be used (they are journal specific).

Here are three (of many) example styles for Headings & Subheadings:

MAIN                                   I. Main           1. Main

Subheading                     i. Subheading 1.               Subheading

Spacing:               For this lab report we are quite specific about the spacing in one section (single space

Abstract) and in the remainder (double space). For this and future reports/essays at the University, if the spacing is not specified for various sections or for the report, it is best to assume double spacing.

Tense: Research reports are always written in past tense.

  1. Title Page: Title, name, student ID, date

Don’t bother including an instructor’s name on this report. If you want to add something which links the report to the course itself, you can always add: “Lab 1 report, Biol*1050. The date on a title page is the date you authored the report (which is the date you last made edits to the document). Dates associated with the study itself such as the date it was initiated, or terminated, or when treatments were applied, etc. are presented within the Materials and Methods section.

  1. Abstract: single spaced, 150-200 words
  2. Introduction: No more than 2 pages double-spaced; includes hypothesis and objective as subheadings (see http://writeonline.ca Genre: Lab Report, Section D)
  3. Materials and methods: Double spaced. This text is based on the information provided in lab and activities you performed. You need to explain how the study was conducted so others can replicate what was done. See grading rubric for guidance. Do not cite the lab outline; you need to paraphrase the material provided.
  4. Results (with bar graphs): You will be given the descriptive statistical measures (average and standard error of the mean) of the observations recorded for your lab section. Present these values using vertical bar charts with standard error of the mean bars; the dependent variable is plotted on the vertical axis and the independent variable on the horizontal axis. See Courselink/Contents/Video Tutorials/Bar charts for information on how to make a column graph with standard error of the mean error bars using excel.

The experiment your section did was a group study, so consider the data from your section as your experiment. When you present a table or graph of the results of your study you do not need to add a reference to that fact. However, you do need to give the table/figure a number, a title to explain what it is, and axis labels.

  1. Discussion: No more than 2 ages double-spaced including the conclusion as a subheading.

Page  | 20

Lab Report Instructions

  1. References:

Primary journal articles are preferred sources. If you are using websites as a source, note that only government websites (Federal/Provincial/State) are allowed for Biol*1050 reports. Non-government websites, including University websites, are not allowed in the lab reports for this course.

We do not limit you to within Canada for either government sites or journals. Scientists need to use the world body of knowledge. Other jurisdictions such as the United States and the European Union are quite permissible.

For directions on how to cite and reference your source material see Courselink/Table of Contents/ Course Schedule/Citing your sources in Biol*1050 reports.

Academic papers are cited using the format: Author Year Title Journal Volume & page range. Do not give the internet pathway you used to view the electronic version of the publication; that is only necessary if it is not a standard publication. For example, here is the WRONG way to cite this article:

  1. Growth and physiological responses of canola (Brassica napus) to three components of global climate change: Temperature, carbon dioxide and drought. [Online] Available from: http://onlinelibrary.wiley.com/doi/10.1111/j.1399-3054.2006.00804.x/full (Accessed 05 October 2016).

Go to that website. The publisher is providing an e-version of the printed journal called Physiolgia Plantarum; this is a journal by the Scandinavian Society for Plant Physiology. Download/Open up the PDF version of the article. It is a copy of the pages from the printed journal. The correct citation format is:

Quaderi, M. M., Kurepin, L. V. and Reid, D. M. 2006. Growth and physiological responses of canola (Brassica napus) to three components of global climate change: temperature, carbon dioxide and drought. Physiol. Plant. 128: 710-721.

The in-text citation would be: (Quaderi et al. 2006). Note that for the reference we use the recognized abbreviation for the journal title (Physiol. Plant.) in place of Physiologia Plantarum. Journal abbreviations can be found here:   https://images.webofknowledge.com/images/help/WOS/A_abrvjt.html

  1. Appendix:

Include the tables of the summarized data provided for you. Do not simply add in a screenshot. The tables must be clear and formatted correctly.

Page | 21

Lab Report Rubric

Grading Rubric (20 points)

Lab Report cont’d

  1. General

1 – All parts of the lab report are present including Title Page and Appendix. 0 – One or more parts of the lab report are missing.

  1. Abstract (see http://writeonline.ca Genre: Lab Report, Section D for further guidance)

1 – Properly formatted and effectively summarizes the experiment.

0 – Too many/few words and/or ineffectively summarizes the experiment.

  1. Introduction (see http://writeonline.ca Genre: Lab Report, Section C for further guidance)

5 – A. Identifies and provides background to organisms being investigated (eg. seed varieties). B. Explores reason for doing the study. C. States hypothesis and objective clearly and coherently as subheadings. D. Writing is structured, objective, analytical and accurate and integrates information appropriately summarized/paraphrased. E. Information is cited correctly.

4 – Provides only four of the above.

3 – Provides only three of the above.

2 – Provides only two of the above. 1 – Provides only one of the above.

0 – Provides none of the above clearly and coherently.

  1. Methods and Materials (see http://writeonline.ca Lab Report Section D for further guidance)

3 –  A. In a clear and coherent manner the organism and dependent and independent variables were identified. B. The experimental conditions were described. C. The steps of the experiment were described.

2 – Provides only two of the above. 1 – Provides only one of the above.

0 – Provides none of the above clearly and coherently

  1. Results (see http://writeonline.ca Lab Report, Sections C and D for further guidance)

3 – A. Provides a clear and coherent written summary of the results and identifies the trends. B. Provides complete graphical presentation of the results with the graph(s) titled and labeled clearly with standard error of the mean error bars (independent variable(s)on x- axis). C. Correctly references the graph(s) in the written summary of the results. (see http://writeonline.ca Lab Report Section C and D and courselink for further guidance) Provides only two of the three above clearly.

Page | 22

Lab Report Rubric

2 – Provides only two of the above. 1 – Provides only one of the above.

0 – Provides none of the above clearly and coherently

  1. Discussion (see http://writeonline.ca Lab Report Section C and D for further guidance)

5 – A. Summarizes the trends in the results in a manner appropriate to a Discussion section. B. Compares the results to published research. C. Discusses limitations of the study and how it could be improved. D. Draws a conclusion about the acceptance or rejection of the hypothesis and the implication for crop yields in response to climate change. E. Writing is structured, objective, analytical and accurate, integrates information appropriately, and summarizes/paraphrases. F. Information is cited correctly.

4 – Provides only four of the above.

3 – Provides only three of the above.

2 – Provides only two of the above. 1 – Provides only one of the above.

0 – Provides none of the above clearly and coherently.

  1. References (For directions on how to cite and references your source material see Courselink/Table of Contents/ Citation Style /Citing your sources in Biol*1050 reports)

1 – References are formatted properly

0 – References are not formatted properly

To reiterate:

  • Non-government websites, including University websites, are not allowed in the lab reports for this course.
  • Do not cite lecture or lab notes as references.
  • Late reports, and reports that are not submitted in pdf format, will receive a grade of 0.
  • The last file uploaded to your dropbox will be the report that will be graded. Make sure it is the version you wish graded.

Note that we will not be reminding you of these requirements in later assignments.

Page | 23