UNIVERSITY OF THE WEST INDIES CAVE HILL CAMPUS Department of Biological & Chemical Sciences

 
BIOL2053 Physiology of Plants & Animals – Plant Project

Physiology is the study of how organisms function and spans from the molecular to the ecological aspects of biology. As physiologists, we want to understand how organisms respond to the environment, ultimately at the cellular and molecular levels. In this course, in addition to exposing you to various techniques used to investigate plant and animal function, we want you to understand the scientific method. Scientific progress is made by questioning the behaviour of an organism, analyzing the questions into manageable parts, posing hypothetical answers and then designing experiments to test those hypotheses.

            Your coursework marks amount to 30% of your final mark for the course and are made up as follows;-            

                                                Laboratory reports       20%
                                                Assignments/tests          10%

Introduction to the Plant Physiology Practical Component

    For the plant half of this course, the practical component will comprise a mini research project you and your lab partner will carry out over a 4-week experimental period. This will teach you how to design an experiment, how to record data and how to interpret and present this. It will also expose you to some techniques widely used in studying plant development. You will also be required individually to research relevant scientific papers and incorporate these into the Introduction and Discussion portions of your project report.

The plant half of the course contributes half of the marks (10+5 =15%) to your final coursework mark. We consider the researching of relevant scientific papers, reading and incorporating these into the Introduction and Discussion sections of your laboratory report as a major and important component of your report. Accordingly, this activity will constitute the assignment portion of your plant coursework, worth a maximum overall of 5%, while the other aspects of your practical report will be worth 10%.

Overview

             There are six practical classes (3 h each) allocated to this project, commencing in Week 1 of Semester 1. You will also be required to attend a weekly tutorial for most of these 6 weeks. Actual practical work will take place for 4 weeks only. It is important that you manage your time effectively so that you meet the submission date of the project report, which is in Week 6. You will work in pairs but your literature research and your write-up must be an individual effort.

            Data interpretation is an important skill we will develop with you in this course so that each practical session will begin with a 10-minute session devoted to data interpretation. A data interpretation question will be offered in the final theory examination.

Objectives

The project you will carry out relates to the material being presented in the lecture course and is designed to achieve a number of objectives. This practical component should help you:

• Understand the scientific method
• Learn how to design and implement simple experiments
• Improve your data interpretation skills
• Appreciate certain techniques used by plant physiologists
• Acquire a basic knowledge of statistical analysis
• Become familiar with the various kinds of scientific literature and how to research this
• Learn how to write a scientific paper
• Develop your time management skills

Investigation:       The environmental basis for differences in shoot development observed in plants from gardens in St Thomas and St Lucy

Experimental design

            The scientific method involves making an observation, then formulating one or more hypotheses to explain your observation and finally designing and carrying out experiments to test the validity of these hypotheses.

            The observation we will make relates to the fact that plants grown in St Thomas look different to those grown in St Lucy. We will have examples of such plants available in the laboratory for you to examine and note how they differ. We will then discuss the appearance of the plants and you will put forward hypotheses to explain how these differences come about.

            Once we have formulated these hypotheses you and your partner will decide which of these you wish to test. We will have available for you 2-week old seedlings of a number of plant species to use in investigating the problem you have selected. Essentially, you will grow seedlings of one plant species under contrasting conditions (“experimental treatments”) and compare their development.

            How many seedlings will you need to plant to carry out the experiment? This will depend on a number of factors not least of which is whether you will be using destructive as well as non-destructive techniques to gather data. You might argue that all you need do is grow one plant under each set of conditions and compare measurements from these two plants. Is this a valid approach? Are those plants identical in every way to start with? Probably not, so that if these plants end up looking different it’s hard to know if that is a result of the different treatments or just the normal variability of the plants. To be confident that any differences detected are really a result of the different treatments we must grow a number of plants, look at the variation among the plants in any one treatment and then see if the differences between treatments are significant. This requires statistical analysis and this will discussed at the practical session in week 2.

The diagram at left shows the main features of a developing dicotyledonous plant such as the one you will be investigating. Note that leaves are numbered from the bottom up on a plant and that the length of stem between consecutive leaves is termed an internode. It is important in doing comparisons that you compare equivalent structures, e.g. it is not valid to be measuring some parameter in the 3^rd leaf of a water-stressed plant but in the 2^nd leaf of a well-watered plant! (Why not?)

Having observed the plants from the two locations you should have some idea of what aspects of shoot development you will want to investigate. There are also other parameters maybe not evident to the naked eye, which you think might be worth investigating. Draw up a list of all the things you could possibly measure and we can then discuss what is practical within the time available. You will certainly all be making weekly measurements of stem and leaf growth. If you wish to measure interim fresh weights, this is destructive testing and means that you will have to plant extra plants so that when you harvest these you still have other plants which can be measured the following week(s).

Ideally, you are going to be investigating only one environmental variable and its effect on plant growth and development. We are going to discuss this in the first laboratory session but here are a number of aspects you might want to think about beforehand (and hopefully you can add some more!);-

• Choice of experimental plant

• Seedling selection

• How many plants?

• Planting the seedlings in the experimental plot

• What to measure?

• Designing your data sheet

• Recording data

Work Schedule

The overall plan of your weekly activities is summarized below; -

Aside from the five 3-h lab sessions you should also spend up to a further 2 hours per week, researching the literature, entering and manipulating your data and writing up the project. The final lab session is free time and should allow you to complete your write up.

Writing up the project

The project should be written up as a scientific paper. Look closely at the examples of papers set out in the lab. The sections are typically in this order;-

•  Title

• Abstract

• Introduction

• Materials & Methods

• Results

• Discussion

• References

• Appendix

Abstract: Provides a summary of what you have found out. It should be written in the past tense and in the passive voice, i.e. "Seedlings were shown to..." not "I have shown that seedlings...". (Max. 250 words – concise, to the point, NO WAFFLE)

 Introduction:  Sets the scene. What are you trying to investigate & why? What relevant work has been previously done – how is this relevant? You need to cite appropriate scientific papers in this section. (Max.  1,000 words)

Materials & Methods:  The information should be concise but complete enough for someone else to repeat the whole experiment from what you have written. Simply reference all standard procedures used. The full scientific name of the plant (including cultivar if known) should be given, as well as dates and cultivation methods.

 Results:  This is not simply your graphs and tables, it is text as well. State what you find out but don't discuss the significance of this.

Discussion:  Firstly, discuss how your results might be interpreted in relation to your hypothesis. Then discuss in relation to the literature. How will your hypothesis be modified, what would you do next?

 References:  Cite all references in text by last names and year of publication. Text citations should be arranged from the earliest to most recent year, alphabetized by name within the same year. List all references cited in a standard format such as that shown below.

Journal articles
Author AB, Author BB (1977) Title of Article. Plant Physiol 59: 45-59

Book articles
Author AB, Author BB, Author CC (1974) Title of article. In A Smith, B Jones, eds, Title of Book, Ed 2 Vol 3. Publisher, City, pp 14-19

Online
Author A (year of publication) Title. Source Title. http://www.utopia.com/talent/lpb/muddex/essay

            Write out in full all one-word journal titles. Use the BIOSIS List of Serials for abbreviations of multiple-word journal titles.

 Appendix:       (Optional) Any raw data, additional information you feel should be submitted.

Click here for a checklist of how to get a good Project Report Grade

CMSC / JA
16 Aug 2004
updated 19 September, 2005