COACHES HANDBOOK FOR BIO-PROCESS LAB TABLE OF CONTENTS

Transcription

1 COACHES HANDBOOK FOR BIO-PROCESS LAB TABLE OF CONTENTS Part A. INTRODUCTION TO BIO-PROCESS LAB A.1 SCIENCE PROCESS SKILLS BASIC AND INTEGRATED A.2 SKILLS AND GRADES 5-8 BACKGROUND VIA NATIONAL STANDARDS A.3 SUPERVISORS AND COACHES GUIDE A.4 PREPARATION TIPS FOR STUDENTS A.5 PRINCIPLES FOR THE DESIGN AND ANALYSIS OF EXPERIMENTS Part B. LESSONS TO DEVELOP LIFE SCIENCE PROCESS SKILLS LESSON 1 LESSON 2 LESSON 3 LESSON 4 LESSON 5 LESSON 6 LESSON 7 LESSON 8 LESSON 9 LESSON 10 LESSON 11 LESSON 12 ANALYSIS AND ERRORS LESSON 13 ANALYSIS OF FOOD LABELS DESIGNING AN EXPERIMENT MICROSCOPE REVIEW AND QUIZ STEREO OR DISSECTING MICROSCOPE REVIEW LAB EQUIPMENT AND PROPER USAGE BALANCE REVIEW METRIC SYSTEM AND MEASUREMENT TIPS INSTRUMENT LAB AND MEASUREMENT LAB TECHNOLOGY FOR DATA COLLECTION OBSERVATIONS AND INFERENCES FORMULATING A DICHOTOMOUS KEY GRAPHING AND DATA ANALYSIS LESSON 14 POPULATION DENSITY AND ECOLOGICAL ANALYSIS LESSON 15 GENETICS BACKGROUND AND SAMPLE PROBLEMS Part C. SAMPLE TOURNAMENTS SAMPLE TOURNAMENT #1 SAMPLE TOURNAMENT #2 SAMPLE TOURNAMENT #3 SAMPLE TOURNAMENT #4 NOTE: ANSWER KEYS ARE INCLUDED AFTER EACH LESSON AND SAMPLE TOURNAMENT. GUIDE TO BIO-PROCESS LAB written by Karen L. Lancour 312 W. Bosley Alpena, Michigan Electronic Version edited by Mark A. Van Hecke August 2007 COPYRIGHT 2008 The SCIENCE OLYM PIAD COACHES MANUEL AND RULES may not be copied without the expressed written permission of Science Olympiad, Inc., except within the school building which holds the membership. Recommended statement to be placed on all printed pages distributed within a school building: Reproduction for distribution within (school name) by permission of Science Olympiad, Inc.

2 Basic Science Process Skills: SCIENCE PROCESS SKILLS 1. Observing - using the senses of sight, hearing, taste, smell, and touch to gather information about an object or event. It is description of what was actually perceived. This information is considered qualitative data. 2. Measuring - using standard measures or estimations to describe specific dimensions of an object or event. This information is considered quantitative data. 3. Inferring - formulating possible explanations based upon observations. It is an educated guess based upon previously gathered observations or data. 4. Classifying - grouping or ordering objects or events into categories based upon characteristics or defined criteria. 5. Predicting - guessing the most likely outcome of a future for an event based upon a pattern of evidence. 6. Communicating - using words, symbols, or graphics to describe an object, action or event. Integrated Science Process Skills: 1. Formulating Hypotheses - stating the expected outcomes for experiments 2. Identifying of Variables - stating the changeable factors that can affect an experiment. It is important to change only the variable being tested and keep the rest constant. The one being manipulated is the independent variable; the one being measured to determine its response is the dependent variable; and all being kept constant are constants or controlled variables. 3. Defining Variables Operationally - explaining how to measure a variable in an experiment. 4. Describing Relationships Between Variables - explain relationships between variables experiment such as between the independent and dependant variables. 5. Designing Investigations - designing an experiment by identifying materials and appropriate steps to test a hypothesis. 6. Experimenting - carrying out an experiment. 7. Acquiring Data - collecting qualitative and quantitative data. 8. Organizing Data in Tables and Graphs - making data tables and graphs for data collected. 9. Analyzing Investigations and Their Data - interpreting data, identifying errors, evaluating the hypothesis, formulating conclusions, and recommending further testing where necessary. 10. Formulating Models - recognizing patterns in data and making comparisons to familiar objects or ideas.

3 SUGGESTED SKILLS AND BACKGROUND AREAS FOR LIFE SCIENCE PROGRAMS BASED UPON NATIONAL STANDARDS I. Skills Related to the Scientific Processes of Investigation A. Identifying problems. B. Formulating hypotheses. C. Recognizing differences between hypotheses, theories, and observations. D. Formulating, evaluating, and following procedures. E. Making observations and formulating inferences. F. Making measurements and collecting data. G. Organizing, presenting, and interpreting data. 1. Making data tables, diagrams, charts, and graphs. 2. Using data to make interpretations, comparisons, and predictions. 3. Recognizing kinds of error as random and experimental. 4. Using data to evaluate hypotheses. 5. Performing calculations as area, density, volume, percent, probability, ratios, and population density. H. Formulating conclusions and inferences. I. Using technology to assist with analysis and formulation of models. J. Understanding new technologies and techniques key to life science labs. K. Communicating and evaluating communications effectively. II. Lab Skills Involved in Life Science Process Lab A. Knowledge of lab safety procedures and safety symbols. B. Identification and proper use of laboratory equipment such as: 1. Compound light microscope. 2. Dissecting or stereo-microscope. 3. Glassware and typical laboratory equipment. 4. Dissecting equipment. 5. Instruments for measurement and their incrementation. 6. Microbiology and molecular genetics instruments. 7. Physiology instruments. 8. Instruments for collecting and preserving specimens. 9. Equipment used to prepare temporary and permanent slides. C. Ability to perform typical laboratory procedures such as: 1. Preparing wet mounts. 2. Formulating and using dichotomous keys. 3. Using stains and indicators. 4. Using sterilization and transfer techniques for microbes. 5. Caring for live organisms.

4 III. Common Background Knowledge for Life Science Based upon the National Science Education Content Standards NOTE: Event Supervisors will provide any specific content necessary in order to perform a requested process task such as the unique morphological features needed to use a dichotomous key. Grades 5-8 A. Structure and Function of Living Systems 1. Levels of organization and the complementary nature of structure and function 2. Structure of cells 3. Functions of cells 4. Tissues and organs 5. Human organism systems 6. Disease - cause and result B. Reproduction and Heredity 1. Continuation of species - sexual and asexual reproduction 2. Sexual reproduction in plants and animals 3. Principles of heredity 4. Traits - influence of heredity and environment C. Regulation and Behavior 1. Homeostasis 2. Regulation of an organism s internal environment 3. Behavior of organisms 4. Evolution of behavior as a result of adaptation D. Populations and Ecology 1. Populations and their interrelationships - food chains & food webs 2. Functions of specific kinds of populations - producers, consumers, decomposers 3. Role of sunlight and transfer of energy through food webs 4. Ecosystems - biotic and abiotic factors & their interrelationships E. Diversity and Adaptation of Organisms 1. Unity of organisms and evidences of common ancestry 2. Biological evolution through adaptation over many generations 3. Causes for extinction of organisms

5 BIO-PROCESS LAB - GUIDE FOR SUPERVISORS, COACHES, & STUDENTS This event is a lab-oriented competition involving the fundamental science processes of a middle school life-science program. The event is not meant to be a comprehensive biology course. If specific content is needed when students are being tested on certain process skills, the supervisor will provide that content. The event consists of a series of biological questions or tasks that involve the use of process skills. Lab Stations and Tasks for Assessing Process Skills Below is a list of lab stations and types of questions or tasks which might be used to assess science process skills. To allow most students to be successful, it may be a good idea for event supervisors to vary the difficulty of questions at each station! Lab Safety Distinguishing "safe" behaviors vs. "unsafe" behaviors, identifying safety symbols, evaluating situations -- what to do "if" or what's wrong. Identifying the proper techniques to handle lab emergencies. Observations Using senses to notice specific features. Identifying similarities and differences in features. Identifying qualitative and quantitative changes in conditions. Using observable properties to classify objects, organisms or events. Inferences Formulating assumptions based upon observations. Distinguishing between observations and inferences. Using observations and inferences to identify testable questions or problems. Problem Using observations to propose a topic for experimentation. Narrowing the scope of the topic to specific testable aspects. Formulate problems within the specific aspects of the topic which are clearly testable. Identify which of the problems can be tested with materials available. Generalizing variables to be considered in testing the problem such as The effect of (the independent variable) upon (the dependent variable.) Hypothesis Proposing a hypothesis for a given problem. Predicting the effect of the change in the independent variable upon the dependent variable. Explaining the relationship or tend that is expected to occur. Providing rationale for a hypothesis or prediction. Determining the testability of a hypothesis based upon materials provided. Evaluating statements presented with a set of data as to their appropriate label.: 1. logical hypothesis, 2. illogical hypothesis of contrary to data, 3. not a hypothesis, but a restatement of data, 4. reasonable hypothesis, but not based on data Predictions Predicting the results for a proposed lab test or setup. Selecting predictions based upon previously observed patterns. Providing rationale for predictions. Lab Equipment Identifying pieces of lab equipment and their function. Identifying appropriate pieces of equipment to perform a specific task. Selecting and using the appropriate piece(s) of lab equipment for a task.

6 Procedures Analyzing procedures for flaws in design. Identifying the proper set of equipment for carrying out an experimental procedure. Arranging steps of procedures in the appropriate order. Determining the repeatability of a procedure. Identifying an appropriate procedure to test a problem. Design Analysis Analyzing designs for experiments relative to problem, Evaluating the basic assumptions used in the design of the experiment. Identifying components as the independent variable, dependent variable, constants (controlled variables), standard of comparison (control), and time period for the test. Evaluating the procedure for repeatability. Evaluating the materials and appropriateness of the steps in the procedure. Identifying appropriate types of qualitative and quantitative data to be collected. Measurement Identifying the capacity, range, and increments of measuring devices as a ruler, graduated protractor, caliper, cylinder, pipet, syringe, or thermometer. Identifying length, temperature, volume, and mass to the capacity of the instrument. Converting units within the metric system. Reading the meniscus when measuring liquids in a cylinder. Balances Identifying types of balances as electronic and triple beam. Determining the capacity of the balance, its increments, its readability, the types of auxiliary weights, the parts of the balance and their function. Determining the mass of an object to the capacity of the instrument. Using auxiliary weights to reach the capacity of a triple beam balance. Microscopy Understanding of parts of microscope & their function, magnification, appearance of images, resolution, changes in field with magnification, types of microscopes and their uses. Preparing a wet mount. Using a light microscope to perform a requested task. Using a dissecting microscope to perform a requested task. Chemical Analysis Identifying the appropriate reagents for specific chemical testing. Using reagents as ph paper, iodine, glucose test paper, bromthymol blue for chemical analysis. Interpreting the results of reagent data. Dichotomous Key Using observations to formulate a dichotomous/taxonomic key. Identifying individuals or objects using a dichotomous key. Identifying similarities and differences in characteristics from a dichotomous key. Calculations Using measurements to determine area, volume, percentages, probabilities, ratios. Determine population density of a sample. Performing statistical analysis of raw data as mean, median, mode, and range. Data Presentation Preparing an appropriate date table, chart, diagram, illustration. Evaluating the presentation of data.

7 Graphing Selecting the appropriate graph for a set of data as line, bar, and pie graphs. Identifying the title, source, independent variable & dependent variables, and the legend. Scaling each axis for a graph. Preparing a line, bar or pie graph to represent a set of data. Predicting data points not included in a given graph and/or making a best line fit. Interpreting a graph and making predictions or inferences based upon the data on a graph. Analysis of Data Identifying sources of experimental error or human mistakes in the data. Determining the validity of results using qualitative and quantitative data. Interpreting graphs as well as charts and diagrams as food webs, pedigrees, Punnett squares, food labels, energy and food pyramids, relationships of organisms. Identifying data which supports or rejects a hypothesis. Identifying discrepancies between stated hypothesis and actual data. Understanding cause and effect relationships. Errors Identifying human mistakes or blunders. Identifying experimental errors as systematic errors and random errors. Making recommendations for eliminating future mistakes or experimental errors. Explaining the effects that human mistakes or experimental errors upon results. Conclusions Selecting the most logical conclusion for given experimental data. Accepting or rejecting hypotheses based upon data analysis. Proposing a new hypothesis for rejected hypotheses. Formulating models Proposing a future test for inconclusive results. Some Helpful Hints for Event Supervisors: It may help to have questions laminated or placed in sheet protectors. This procedure eliminates damage or tampering during competition. Taping questions to the table helps to keep stations organized and undisturbed. Bring extra items needed at stations as extra rulers. Quick supervisor checklist of useful items to include stop watches, answer sheets, extra set of questions, tie-breaker sheets, answer keys, highlighter, calculator, extra pencils, red pens, extra mm rulers, stapler, masking tape, scotch tape

8 BIO-PROCESS LAB - GUIDE FOR SUPERVISORS, COACHES, & STUDENTS This event is a lab-oriented competition involving the fundamental science processes of a middle school life-science program. The event is not meant to be a comprehensive biology course. If specific content is needed when students are being tested on certain process skills, the supervisor will provide that content. The event consists of a series of biological questions or tasks that involve the use of process skills. Lab Stations and Tasks for Assessing Process Skills Below is a list of lab stations and types of questions or tasks, which might be used to assess science process skills. To allow most students to be successful, it may be a good idea for event supervisors to vary the difficulty of questions at each station! Lab Safety Distinguishing "safe" behaviors vs. "unsafe" behaviors, identifying safety symbols, evaluating situations -- what to do "if" or what's wrong. Identifying the proper techniques to handle lab emergencies. Observations Using senses to notice specific features. Identifying similarities and differences in features. Identifying qualitative and quantitative changes in conditions. Using observable properties to classify objects, organisms or events. Inferences Formulating assumptions based upon observations. Distinguishing between observations and inferences. Using observations and inferences to identify testable questions or problems. Problem Using observations to propose a topic for experimentation. Narrowing the scope of the topic to specific testable aspects. Formulate problems within the specific aspects of the topic which are clearly testable. Identify which of the problems can be tested with materials available. Generalizing variables to be considered in testing the problem such as The effect of (the independent variable) upon (the dependent variable.) Hypothesis Proposing a hypothesis for a given problem. Predicting the effect of the change in the independent variable upon the dependent variable. Explaining the relationship or tend that is expected to occur. Providing rationale for a hypothesis or prediction. Determining the testability of a hypothesis based upon materials provided. Evaluating statements presented with a set of data as to their appropriate label.: 1. logical hypothesis, 2. illogical hypothesis of contrary to data, 3. not a hypothesis, but a restatement of data, 4. reasonable hypothesis, but not based on data Predictions Predicting the results for a proposed lab test or setup. Selecting predictions based upon previously observed patterns. Providing rationale for predictions. Lab Equipment Identifying pieces of lab equipment and their function. Identifying appropriate pieces of equipment to perform a specific task. Selecting and using the appropriate piece(s) of lab equipment for a task.

9 Procedures Analyzing procedures for flaws in design. Identifying the proper set of equipment for carrying out an experimental procedure. Arranging steps of procedures in the appropriate order. Determining the repeatability of a procedure. Identifying an appropriate procedure to test a problem. Design Analysis Analyzing designs for experiments relative to problem, Evaluating the basic assumptions used in the design of the experiment. Identifying components as the independent variable, dependent variable, constants (controlled variables), standard of comparison (control), and time period for the test. Evaluating the procedure for repeatability. Evaluating the materials and appropriateness of the steps in the procedure. Identifying appropriate types of qualitative and quantitative data to be collected. Measurement Identifying the capacity, range, and increments of measuring devices as a ruler, graduated protractor, caliper, cylinder, pipet, syringe, or thermometer. Identifying length, temperature, volume, and mass to the capacity of the instrument. Converting units within the metric system. Reading the meniscus when measuring liquids in a cylinder. Balances Identifying types of balances as electronic and triple beam. Determining the capacity of the balance, its increments, its readability, the types of auxiliary weights, the parts of the balance and their function. Determining the mass of an object to the capacity of the instrument. Using auxiliary weights to reach the capacity of a triple beam balance. Microscopy Understanding of parts of microscope & their function, magnification, appearance of images, resolution, changes in field with magnification, types of microscopes and their uses. Preparing a wet mount. Using a light microscope to perform a requested task. Using a dissecting microscope to perform a requested task. Chemical Analysis Identifying the appropriate reagents for specific chemical testing. Using reagents as ph paper, iodine, glucose test paper, bromthymol blue for chemical analysis. Interpreting the results of reagent data. Dichotomous Key Using observations to formulate a dichotomous/taxonomic key. Identifying individuals or objects using a dichotomous key. Identifying similarities and differences in characteristics from a dichotomous key. Calculations Using measurements to determine area, volume, percentages, probabilities, ratios. Determine population density of a sample. Performing statistical analysis of raw data as mean, median, mode, and range. Data Presentation Preparing an appropriate date table, chart, diagram, illustration. Evaluating the presentation of data.

10 Graphing Selecting the appropriate graph for a set of data as line, bar, and pie graphs. Identifying the title, source, independent variable & dependent variables, and the legend. Scaling each axis for a graph. Preparing a line, bar or pie graph to represent a set of data. Predicting data points not included in a given graph and/or making a best line fit. Interpreting a graph and making predictions or inferences based upon the data on a graph. Analysis of Data Identifying sources of experimental error or human mistakes in the data. Determining the validity of results using qualitative and quantitative data. Interpreting graphs as well as charts and diagrams as food webs, pedigrees, Punnett squares, food labels, energy and food pyramids, relationships of organisms. Identifying data which supports or rejects a hypothesis. Identifying discrepancies between stated hypothesis and actual data. Understanding cause and effect relationships. Errors Identifying human mistakes or blunders. Identifying experimental errors as systematic errors and random errors. Making recommendations for eliminating future mistakes or experimental errors. Explaining the effects that human mistakes or experimental errors upon results. Conclusions Selecting the most logical conclusion for given experimental data. Accepting or rejecting hypotheses based upon data analysis. Proposing a new hypothesis for rejected hypotheses. Formulating models Proposing a future test for inconclusive results. Some Helpful Hints for Event Supervisors: It may help to have questions laminated or placed in sheet protectors. This procedure eliminates damage or tampering during competition. Taping questions to the table helps to keep stations organized and undisturbed. Bring extra items needed at stations as extra rulers. Quick supervisor checklist of useful items to include stop watches, answer sheets, extra set of questions, tie-breaker sheets, answer keys, highlighter, calculator, extra pencils, red pens, extra mm rulers, stapler, masking tape, scotch tape

11 Team work skills BIO-PROCESS LAB - Student Preparation Tips - Use time effectively! Assign tasks and trust your partner s skills. - Identify and utilize the strengths of each team member. - Practice working as a team. Time limits - Practice under competition conditions. - Practice effective methods of using the strength of each team member to maximize the use of allotted time. - Make up sample questions and stations to practice completing tasks within an assigned time limit. Answering questions - Carefully read all questions to determine exactly what is being asked. - Take a moment to determine if your answer makes sense. - Be certain that your have completely answered each question. - Pay attention to details in the questions and in your answers. Measurements and Calculations - Be sure to analyze the instrument to determine it's capacity (range) and increment values to insure the proper use of the instrument. Make measurements to the accuracy of the instrument. - Select the most appropriate type of instrument for the type of measurement requested. - Read the increment carefully. Be sure to remember any special considerations such as a meniscus. - Use the same instrument for multiple measurements to improve precision. - Give your answer in the proper units and be sure to include the units with your answer. - Be sure calculations are set up and carried out properly. Work in a neat organized fashion showing all work where partial credit is possible. Be sure your answer makes sense. - Remember that calculations may be used for breaking ties. Reference materials - Review the process skills involved in doing life science labs and designing or evaluating investigations.. - Review the identity and appropriate use of common lab equipment. - Use your school's life science textbook and lab manual to help you develop practice lab stations and questions PRINCIPLES OF EXPERIMENTAL DESIGN A controlled experiment is an experiment where all of the environmental variables or factors are controlled (kept constant or normal) except for the factor being tested. The parts of an experiment are as follows: PROBLEM: A statement that defines the topic of the experiment and identifies the relationship between the two variables. Be specific enough to allow the design of an experiment. It should generalize the factors being tested as The effect of the (independent variable) upon the (dependent variable). HYPOTHESIS: A statement that predicts the outcome of testing the relationship between the independent variable and the dependent variable as specified in the problem. Be sure to include your rationale for this prediction.

12 VARIABLES: Environmental factors or conditions which can change. Independent Variable is the factor being purposely changed or manipulated. Dependent Variable is the factor, which responds to the change in the Independent Variable. Its response is measured as data. Constants (controlled variables) are all other factors, which are not manipulated during the experiment. These are often potential independent variables for future experiments. EXPERIMENTAL CONTROL (STANDARD OF COMPARISON): The component in which the independent variable is not changed or manipulated. It is used to verify that from trial to trial everything is kept the same and that the change in the independent variable is actually causing the response in the dependent variable. MATERIALS AND PROCEDURE: A recipe for conducting the experiment. It consists of a list of materials/equipment followed by step-by-step instructions. These instructions must be specific enough to allow the experiment to be repeated exactly the same way each time it is conducted. Specify what type data should be collected during the experiment in order to measure the response of the dependent variable. QUALITATIVE DATA: Observations or descriptions of things noticed with the senses during the course of the experiment and any data based on a nonstandard scale. Observations may pertain to things that happen relative to the dependent variable as well as those are not directly related to the dependent variable, the procedure, or and things that went wrong during the experiment. These types of observations may assist you in identify errors and evaluating the results. Qualitative data is usually categorized by factors such as color, texture, shape, size, and behavior and is organized into a table, diagram, or flow chart. You may draw pictures to show what you observed. Qualitative data may be as important as the measurements in evaluating the results so do not under estimate their worth. QUANTITATIVE DATA: Data that is based upon measurement and the presentation of this data. When organizing data for analysis, use visual tools as data tables, graphs, diagrams or flow charts. Be sure to thoroughly label all graphs, diagrams or flow charts. Measurement: A measurement requires both magnitude (how much) and a unit. Examine the instrument to be sure you know its capacity and the value of the numbered graduations or increments as well as the unnumbered ones. Be sure to select the appropriate instrument for the proper degree of accuracy. When you are measuring liquids in a cylinder or pipette, remember to read the bottom of the meniscus curve. Data Tables: Use data tables to organize data as it is collected. Be sure all data raw data is given and that the correct significant figures are used and units are included. Also be sure all appropriate labels are included. Provide another condensed table with the most important data. Graphs: When graphing, remember that the independent variable goes on the horizontal or X - axis while the dependent variable goes on the vertical or Y- axis. To scale or number the axis of a graph so it will always fit the grid, use the following formula: High value - Low value (use zero if you plan to start numbering by zero) divided by the number of spaces on that axis. Always round up. Begin numbering with your lowest value and go up by your calculated graduation. Be sure to include all appropriate labels. STATISTICAL ANALYSIS OF DATA: Measure of Central Tendency: A value at the center of the data set. It can be measured as the mean or average, the median, or the mode. Measure of Variation: For qualitative data, a frequency table or histogram can be used. For quantitative data, the range and standard deviation should be used.

13 Regression Analysis: Using an equation or graph to show the relationship of variables. Finding the line of best fit is often used. Percent Error: Another common form of statistic analysis. ANALYSIS OF RESULTS: Evaluate the qualitative and quantitative data. How do the results of your various trials compare? What was learned from this experiment? What trend was established? Does the data support your hypothesis? Why or Why not? POSSIBLE EXPERIMENTAL ERRORS: Any human mistakes that were made and any experimental errors that became evident. What effect did these errors and/or mistakes have on the qualitative or quantitative data. What went wrong during the experiment and how should the experiment have been done differently to avoid these problems in the future? CONCLUSION: Restate the hypothesis and summarize the major results. Explain why the results did or did not support the hypothesis. Include what was learned and any unexpected results. RECOMMENDATIONS FOR FURTHER INVESTIGATION AND APPLICATIONS: Recommend modifications of the experiment design or procedure. For future testing, give suggestions for refinement of your hypothesis based upon your data. Include other aspects of the general topic that should be considered for future investigations in order to better understand the general topic or question. Finally give practical applications for the principles obtained from the experiment. REPORT: The report will be written. Use the outline provided by the event supervisor to organize your report. It is similar to the rubric that will be used to evaluate your report. QUESTIONS TO ASK WHEN ANALYZING THE DESIGN OF AN EXPERIMENT 1. What was this study trying to determine? 2. Was the problem testable? 3. Was the hypothesis a testable prediction? 4. What was the independent variable (the factor being tested)? 5. What was the dependent variable (the factor responding to the test)? Was it measured quantitatively? 6. What made up the experimental group (the group being tested)? Was it a representative sample? 7. What made up the control group (the group not tested for the independent variable)? Was there a control group and was it a representative sample of the same type as the experimental group? 8. List the controlled variables ( those factors not being tested). Are all of these factors kept normal and the same for both groups? Remember the independent variable for the experimental group is the only thing that should be tested. 9. Are there any weaknesses in the design of this experiment? List those weaknesses. 10.How would you change the design of this experiment to correct these weaknesses? Background information: DESIGNING AN EXPERIMENT A controlled experiment is an experiment where all environmental factors or conditions are controlled (kept constant or normal) except for the factor being tested. A variable is an environmental factor or condition. An independent variable is the factor or condition being tested. The dependent variable is the factor which responds to the change in the independent variable. It's response is measured as data. Controlled variables are all other factors or conditions which are kept constant or normal during the experiment.

14 Most experiments have two groups of subjects - an experiment group and a control group. The number in each group is determined by the designer of the experiment. The experimental group is the group being tested by having the independent variable changed. The control group is the group in which the independent variable is not changed but treated as a controlled variable. Assignment: 1. Choose one of the listed problems or formulate one of your own. 2. Formulate a working hypothesis as a proposed solution to your problem. 3. Identify each of the following relative to your proposed solution. A. Independent variable B. Dependent variable C. Controlled variables D. Experimental group E. Control group 4. Develop a list of materials and a simple procedure to enable a person to test your proposed solution. 5. Predict what will happen and indicate what evidence should be collected as your proposed solution is being carried out. 6. Write this assignment in a final form including parts 1-5. Be sure to use complete sentences and proper grammar. Some Sample Problems: 1. How does water affect the germination of seeds? 2. Which type of music allows plants to grow the best? 3. How does caffeine affect the heart rate of a Daphnia? 4. Do yeast need the same vitamins as man? 5. How does temperature affect the activity of enzymes? 6. How does the amount of sugar affect the rising of bread or pizza dough? 7. What role can enzymes play in cleaning up our water? 8. What effect do various types of textured walls have on sound? 9. What minerals promote the best plant growth? 10. What effect does the intensity of light have on the response of planaria to light?

15 DESIGNING AN EXPERIMENT (A sample of a student's work) Background: Daphnia are creatures that can be observed under a microscope. With the microscope you can see and count their heartbeat. This makes them good for testing the affects of caffeine on heart rate. Problem: How does caffeine affect the heart rate of a Daphnia? Hypothesis: If Daphnia is given a variety of different pops such as Coke, Mountain Dew and 7-up, then the Mountain Dew will make the greatest increase in the Daphnia's heart rate. Variables: The independent variable in this experiment will be the three different types of pop. The dependent variable is the heart rate and the controlled variables are the temperature and food. The Daphnia which get the different type of pop are the experimental group, and the control group is the Daphnia which get no pop at all. Materials: To perform this lab you will need four Daphnia, and eye dropper, Coke, Mountain Dew, 7-up, a microscope, a well slide and four dishes to hold the Daphnia. Procedure: Measure and record the heart rate in beats per minute of each Daphnia. Put each of the four Daphnia in different dishes. Put two drops of Coke in the first dish, two drops of Mountain Dew in the second dish, two drops of 7-up in the third dish and none in the last one. After a half an hour find the heart rate of the three experimental Daphnia, also in beats per minute and record the information. Then compare which pop caused the Daphnia's heart rate to speed up the most. Data Requirements: 1) Record the heart rate of each Daphnia before putting in the pop. 2) Record the heart rate of each of the experimental Daphnia after the pop has been in a half an hour. 3) Compare the results to see which one increased the most and which one increased a little if at all.

16 MICROSCOPY REVIEW Parts of the microscope and their function: The number in front of each part of the microscope represents its number on the diagram. 1. ocular - magnifies the image formed by the objective. 2. nosepiece - holds the objectives. 3. objectives - lenses that receive the light from the field of view and form the first image. 4. stage - supports the slide and the specimen. 5. stage clips - hold the slide in place. 6. base - foundation which supports the scope & keeps it stable. 7. diaphragm - controls the amount of light reaching the specimen. 8. illuminator - source of light. 9. course adjustment - used for initial or low power adjustment. 10. fine adjustment - used for fine tuning & high power focusing. 11. arm - supports the ocular, objectives and body tube. 12. body tube - tube or barrel between the ocular and the objectives.

17 PRINCIPLES OF MICROSCOPY A. Appearance of objects 1. Inverted and reversed (upside-down & backwards) 2. If an "e" is placed in the stage in its normal position, it will appear as an " ". 3. Only a thin layer of the specimen is in focus at any level (depth of focus). B. Movement of specimens 1. Actual movement is opposite to appeared direction of movement. 2. If an organism is actually moving ( ), it will appear to be moving ( ). C. Total magnification 1. Multiply ocular magnification times objective magnification. 2. Oculars are normally 10X or 12X. 3. Objectives are typically as follows: a. scanning power - 4X or 5X or 6X b. low power - 10X or 12X c. high power - 40X or 43X or 45X 4. Sample problem: If the ocular is 10X and the objective is 43X, the total magnification is 430. D. Changing objectives 1. When changing objectives from scanning power to lower power to high power, the following changes will occur: a. the size of the field of view decreases. b. the field of view is darker. c. the size of the image increases.. d. the resolution (ability to separate small details) increases. e. the working distance (distance between coverslip & objective) decreases. f. the depth of focus (thickness of the specimen which may be seen in focus) is reduced. 2. The relationships of magnification and the fields of view diameter and area ratios are approximately (10 X ocular and listed objective) objective scanning 5X low 10X high 40X total magnification diameter - 1/2 scanning 1/4 low area - 1/4 scanning 1/16 low

18 PRINCIPLES OF ADVANCED MICROSCOPY A. Measuring the diameter of the field of view. 1. Place a transparent millimeter ruler on the stage, hold it down with the stage clips, and observe the ruler in the desired field of view - scanning or low. (See Fig. 1) 2. Focus on the metric edge of the ruler. Hint: applying gentle pressure to the free end of the ruler will help adjust for the thin ruler and allow for better focus. 3. Place the center of one millimeter marking at the left edge of the field of view (see Figure 2) and measure the diameter of the field in millimeters. For reference: Scanning power (50X) is about 3.0 to 3.2 mm and low power (100X) is about 1.5 to 1.6 mm. Sizes will vary with changes in magnification and manufacturer. 4. Convert the measurement in millimeters to micrometers by multiplying by Samples: low power field 1.6 mm X µm/mm = 1600 µm or mcm scanning power field 3.2 mm X 1000 µm/mm = 3200 µm or mcm 5. The diameter of the high power field is less than one millimeter. It can be calculated from the diameter of the low power field by using the following formula: high power field diameter = low power magnification lower power field diameter high power magnification Sample: h.p. field = 100 to h.p. field = 100 X 1600 = 400 µm or mcm 1600 µm B. Estimating the size of an object. 1. Determine the number of cells or objects that would fit across the diameter of the field of view. 2. Estimate the size of the object by dividing the diameter of the field by the number of the objects that would fit across the field. Sample: a. diameter of the field is 2 mm x 1000 µm/mm = 2000 µm b. length of cell "x" is 2000 µm/ 3 cells = 660 µm/cell

19 DEPTH OF FOCUS EXERCISE Below are four objects located between a slide and a coverslip. The actual objects would of course be 3-D. The objects are left to right; a cone, a cylinder, a sphere and a cube. As one focuses down through the various levels a two dimensional representation will be visible. At each level (represented by the dotted lines to the slide diagram) draw what two dimensional shapes would be present and give their proper location on the slide diagram.

20 ANSWER KEY FOR DEPTH OF FOCUS EXERCISE Below are four objects located between a slide and a coverslip. The actual objects would of course be 3-D. The objects are left to right; a cone, a cylinder, a sphere and a cube. As one focuses down through the various levels a two dimensional representation will be visible. At each level (represented by the dotted lines to the slide diagram) draw what two dimensional shapes would be present and give their proper location on the slide diagram.

21 MICROSCOPY QUIZ I. PARTS OF THE MICROSCOPE: For each of the following parts of the microscope, give the letter representing it's function and the number representing it's location. PART ocular coarse adjustment fine adjustment arm nosepiece objectives stage stage clips diaphragm illuminator base FUNCTION A. holds slide in place B. foundation to keep scope stable C. controls the amount of light to specimen D. supports slide and specimen E. lens that form initial image of specimen F. holds objectives - allows changing power G. used for initial & low power focusing H. supports ocular, objectives & body tube I. source of light J. magnifies image formed by objective K. used for fine tuning & high power focusing LOCATION

22 II. MICROSCOPY SKILLS: 1. A student prepares a slide of the letter "d" and positions the slide on the stage of the microscope so the letter is in the normal reading position. When viewed through the microscope, the image of the letter will appear as A. d B. b C. q D. p 2. An organism viewed under the microscope appears to be moving " ". The organism is actually moving A. B. C. D. 3. A student observes a specimen under high (400X) power and then switches back to low (100X) power. How will the appearance of the image change when going from high power to low power? A. larger and darker B. smaller and darker C. smaller and brighter D. larger and brighter 4. A microscope is equipped with a 10X ocular and two objectives - one is 10X and the other is 43X. What is the highest total magnification possible with this microscope? Questions 5-9 are based upon the following diagram: 5. The diagram represents a field of view through a compound light microscope. What is the diameter of the field of view in millimeters (mm)? 6. What is the diameter of this field of view in micrometers (µm)? 7. What is the approximate length of the organism in micrometers ( µm)? 8. This diagram represents the field of view under low power with a total magnification of 100X. If the high power field is 400X, what would be the diameter of the high power field in micrometers? 9. When you switch from low power to high power, what happens to depth of focus? A. it will be greater B. it will be less C. it will remain the same D. it will be nonexistent

23 ANSWER KEY FOR MICROSCOPY QUIZ I. PARTS OF THE MICROSCOPE: For each of the following parts of the microscope, give the letter representing it's function and the number representing it's location. PART FUNCTION 1. J ocular A. holds slide in place 9. G coarse adjustment B. foundation to keep scope stable 10.K fine adjustment C. controls the amount of light to specimen 11.H arm D. supports slide and specimen 2. F nosepiece E. lens that forms initial image of specimen 3. E objective F. holds objectives - allows changing power 4. D stage G. used for initial & low power focusing 5. A stage clips H. supports ocular, objectives & body tube 7. C diaphragm I. source of light 8. I illuminator J. magnifies image formed by objective 6. B base K. used for fine tuning & high power focusing LOCATION

24 II. MICROSCOPY SKILLS: D 1. B 2. C 3. A student prepares a slide of the letter " d " and positions the slide on the stage of the microscope so the letter is in the normal reading position. When viewed through the microscope, the image of the letter will appear as A. d B. b C. q D. p An organism viewed under the microscope appears to be moving " ". The organism is actually moving A. B. C. D. A student observes a specimen under high (400X) power and then switches back to low (100X) power. How will the appearance of the image change when going from high power to low power? A. larger and darker B. smaller and darker C. smaller and brighter D. larger and brighter A microscope is equipped with a 10X ocular and two objectives - one is 10X and the other is 43X. What is the highest total magnification possible with this microscope? Questions 5-9 are based upon the following diagram: mm 5. The diagram represents a field of view through a compound light microscope. What is the diameter of the field of view in millimeters (mm)? µm 6. What is the diameter of this field of view in micrometers ( µm)? 600 µm 7. What is the approximate length of the organism in micrometers? µm 8. This diagram represents the field of view under low power with a total magnification of 100X. If the high power field is 400X, what would be the diameter of the high power field in micrometers? B 9. When you switch from low power to high power, what happens to depth of focus? A. it will be greater B. it will be less C. it will remain the same D. it will be nonexistent

25 STEREO OR DISSECTING MICROSCOPE Dissecting microscopes are stereomicroscopes, instruments that are used for obtaining a threedimensional view of a specimen. (Stereoscopy is simultaneous vision with two eyes producing a unique vision in which the observer can perceive the relative distances of objects in space.) Stereomicroscopes are essentially two compound microscopes that are both trained on the same sample. Each microscope consists of an objective, a prism-erecting system (which erects the image, and an eyepiece). The angle between the two chambers of the microscope is usually about 10 degrees. Objects appear normal they are not inverted and reversed. Stereoscopic microscopy has advantages and disadvantages to other microscopes. An obvious advantage is that stereomicroscopes produce a truly three-dimensional image, which can be useful in determining the exact location of objects. For this reason, having a three-dimensional image is important in microdissection. Also, stereomicroscopes have a favorable depth of field. Another advantage of stereomicroscopes is that they can be fitted with a fluorescent lamp. Another characteristic of stereomicroscopes is that they have a much lower magnification limit than other microscopes, such as the compound microscope, for instance. The stereomicroscope can magnify an image times, while normal compound microscopes can magnify an image times. This can be a disadvantage of stereomicroscopes, because not as much detail of the image is seen. However, having a lower magnification limit can also be favorable. For example, a lower magnification can allow one to see more of the object than a higher magnification, which makes the object interpreted more easily.

26 LAB ITEMS AND THEIR USES Picture Name Usage Balance Electronic Balances are used to determine the weight of objects. The capacity varies with the model as does the incrementation. Balance Triple Beam with weights Balances are used to determine the weight of objects. The auxillary weights extend the capacity of the balance up to 2610 g Beaker Beakers are used to hold and heat liquids. The graduations for estimation. Bottle Bottles can be used for storage, mixing or displaying. Bunsen Burner Bunsen burners are used for heating and exposing items to flame. They have many more uses than a hot plate, but do not replace a hot plate. Caliper Vernier Calipers are used to measure the inside and outside diameter of cylinders. The Vernier scale allows more accurate measurement. Culture dishes Culture dishes are used to house and culture small plants and animals. There are also small varieties

27 Crucible Crucibles are used to heat small quantities to very high temperatures. Dialysis tubing Dialysis tubing is used for osmosis experiments. It is a thin membrane which controls the size movement of materials. Dissecting Kit Dissecting kits contain instruments that are used for dissection such as scissors, forceps, scalpels, probes. Dissecting Pan The dissecting pan is used to hold the item being dissected. Dissecting pins are used to hold the specimen in place Dropping Bottles Dropping bottles are used to hold liquids and have a stopper with a dropper for dispensing the liquids. Erlenmeyer Flask The Erlenmeyer Flask is used to heat and store liquids. The advantage to the Erlenmeyer Flask is that the bottom is wider than the top so it will heat quicker because of the greater surface area exposed to the heat. Evaporating Dish Florence Flask The Evaporating Dish is used to heat and evaporate liquids. The Florence Flask is used for heating subtances that need to be heated evenly. The bulbed bottom allows the heat to distribute through the liquid more evenly. The Florence Flask is mostly used in distillation experiments.

28 Funnel The funnel can be used to dispense liquids into any container so they will not be lost or spilled. Graduated Cylinder Graduated cylinders are used to measure the volume of liquids. They come in a variety of capacities and increments. Meter stick A meter stick is used to measure the length of objects up to one meter. Smaller versions are called metric rulers. Microscope slides Microscope slides are used to hold specimens to be examine with a compound microscope. Microscope Coverslips Coverslips are placed over the liquid bubble on a slide so the image can be examined without getting the liquid on the lens of the microscope. Microscope Compound Compound microscopes are used to examine small objects with a magnification range usually from 40X to 1000X. Observed images appear inverted and reversed. Microscope Stereo or Dissecting Stereo or Dissecting microscopes are used to observe larger objects or objects being dissected. Observed images are appear normal. Magnification ranges is usually from 20X to 40X. Petri dish Petri dishes are used to culture bacteria. They can also be used as small lab dishes with a cover.

29 Pipet The pipet is used for moving small amounts of liquid from place to place. They are usually made of plastic and are disposable Ring Stand Ring stands are used to hold items being heated. Clamps or rings can be used so that items may be placed above the lab table for heating by bunsen burners or other items. They can also be used to hold objects as probes steady during data collection. Safety Goggles Spatula Syringe Safety goggles are worn to protect the eyes. They should be worn whenever glassware and/or chemicals are used. The spatula is used for moving small amounts of solid from place to place. Syringes are used to measure and dispense a specific volume of a liquid. They come in a variety of capacities and increments. Test Clamp Test Holder The test tube clamp is used with a ring stand to Tube hold a test tube or probe in place during an experiment. tube The holder is used to hold test tubes when they are hot and untouchable. Test Rack The test tube rack is used to hold test tubes tube while reactions happen in them or while they are not needed. Thermometer Tongs The thermometer is used to take temperature of solids, liquids, and gases. They are usually graduated in o C, but can also have increments in o F Tongs are used to hold many different things such as flasks, crucibles, and evaporating dishes when they are hot.