BIO A1 worksheet - Professor Greg Dahlem PDF

Preview

Summary

Professor Greg Dahlem...

Description

WORKSHEET #1: THE SCIENTIFIC METHOD ESSENTIALS OF BIOLOGY: CHAPTER 1 1. READ CHAPTER 1 (focus on Section 1.3, pages 11-16) 2. WATCH VIDEOS:  “The Scientific Method” https://www.youtube.com/watch? v=H21xs1p0VTc  “Pitfalls of Thinking: Anecdotal Evidence” https://www.youtube.com/watch?v=fJWxajLJPtU  “Junk Science Episode 10: Correlation / Causation” https://www.youtube.com/watch?v=Cl8zetzDBfM TERMINOLOGY TO KNOW 1. Hypothesis - A proposed 2. Test group – The group that explanation made w/ little receives the variable being evidence, a starting point for tested in the experiment. further explanation. 3. Control group – The group that 4. Placebo – A pill that has no real does not receive the variable effect. Usually used to benefit the being tested. patient psychologically. 5. Experimental variable – The 6. Scientific theory – concept particular item or action we are supported by observations, changing (testing). experiments & data. 7. Responding (or dependent) variable – The item or action we are measuring. 8. Anecdotal evidence* – non9. Sample size* – The number of scientific observations, which do subjects included in a sample. not provide proof, but may assist in research. 10. Statistical significance* 11. Correlation* – A mutual – The likelihood that a relationship or connection relationship between two or more between two or more things. variables is caused by something other than random chance. Note - * = from lecture, not in book TEST YOUR KNOWLEDGE: 1. Answer the following multiple choice questions from Chapter 1 on page 20. a. 8, 9, and 10 8.) A hypothesis cannot be formed without which of the following?

B.) Observation 9.) Information collected from a scientific experiment is known as: C.) Data 10.) Placebos are often used in which of the following? B.) Control Groups CONCEPTS TO KNOW AND BE ABLE TO EXPLAIN 1. Stages of a Scientific Investigation (4 steps) a. Our textbook breaks down the stages of a scientific investigation into 4 steps. These are the first four subheadings of section 1.3 in textbook. Know these. 1.) Start w/ an observation 2.) Develop a hypothesis 3.) Make a Prediction & Perform Experiments 4.) Develop A Conclusion 2. Start with an observation a. We can make observations with any (or all) of our 5 senses. What are the 5 human senses? - Hearing, sight, touch, smell, taste b. In addition to making personal observations, scientists expand their understanding of the situation further by doing what before they make a hypothesis? - Look up past studies on the internet or at the library, or write or speak to others who are researching similar topics 3. Develop a hypothesis a. Why is a hypothesis considered to be much more than just a guess? - Because it is based on existing knowledge b. What is the only type of hypotheses that a scientist should consider? - Ones that can be tested by experiments or further observation 4. Make a prediction and perform experiments a. A good experimental design ensures two things. What are they? - That scientists are testing what they want to test & that their results will be meaningful. b. *In a good experiment, the researcher attempts to keep all the conditions constant except for one (the experimental variable). Why is this so important, especially when comparing results of a test group with a control group? c. *When we analyze data obtained from an experiment we often use statistics. What is the relationship between statistical significance and the sample size? d. Be able to distinguish the independent variable from the responding (or dependent) variable - An independent variable is the variable that is changed to test the effects it has on the dependent variable. The dependent variable is the variable being tested and measure.

e. *Be able to explain why correlation does not equal causation - data may show correlation between 2 variables, but that doesn’t prove that one variable causes the other. f. *Be able to give an example of two things that are correlated, but do not cause one another. - drowning deaths and consumption of ice-cream 5. Develop a conclusion a. Is an experiment considered to be a failure if the conclusion is to reject the hypothesis? Explain. - No, it can help a scientist formulate another hypothesis to be tested. b. What does it mean when we say that experiments and observations must be repeatable? - Any scientist who repeats the experiment must get the same results, or else the data are suspect. 6. An example of a controlled study a. Be able to describe how to set up a controlled experiment (see Figure 1.10) - State hypothesis, perform experiment, collect data. - The control group would receive a placebo, test group 1 received medication A and test group 2 received medication B. b. How are subjects divided into experimental and control groups? - Randomly 7. Publish your results a. Before an experiment is published in a scientific journal, it must undergo review by a group of experts in the field. Why? - To ensure that the research is credible, accurate, unbiased and well executed & to ensure the experimental is repeatable. b. Why is it important that results are published in a scientific journal rather than self-published by the people doing the experiment? - So that all aspects of a study are available to the scientific community. Feedback is important so that researchers can critically review their hypothesis, predictions and experimental designs. DETAILS (important for open-note quizzes!) 1. What causes most stomach and intestinal ulcers? - The bacterium Helicobacter pylori 2. What is the scientific name of the model organism often used by developmental biologists (Figure 1.9) - Caenorhabditis elegans...