Day 1 – Introduction & Procedures

Do now Get out a sheet of paper and put your name on it! IN YOUR GROUPS (QUIET TALKING)

What is toxicity? Something is toxic when it can damage or kill an organism. Every substance has a certain toxicity to it, but the amount depends on what that substance is and what organism is exposed to it. TEACHER (TALK WHEN CALLED ON)

How do you measure toxicity? Toxicity is measured by giving a series of doses to an organism, each dose being more concentrated than the last. Scientists typically try to find the dose at which half (50%) of the exposed organisms perish. TEACHER (TALK WHEN CALLED ON)

Dose/Response Video ?v=yyvX5hDBPBY IN YOUR GROUPS (QUIET TALKING)

Terms for toxicity? There are two terms for toxic doses. LD50: Lethal Dose, 50% (animals and humans) TC50: Toxic Concentration, 50% (plants and fungi) TEACHER (TALK WHEN CALLED ON)

The investigation You will be using a bioassay to find the TC50 for lettuce seeds for the substance of your choice. TEACHER (TALK WHEN CALLED ON)

Bioassay An experiment type that uses a live organism to determine biological activity (such as growth, response to toxins, etc.). TEACHER (TALK WHEN CALLED ON)

Scoring Readiness: 4 points Introduction: 4.5 points Procedure: 5.5 points Inquiry: 4 points Results: 4 points Conclusion: 5.5 points Presentation: 2.5 points (graded as a group) TOTAL: 28 points TEACHER (TALK WHEN CALLED ON)

Scoring A rubric will be made available online for you. You can also get one from me if you bring in a flash drive. I will have a copy of the rubric available in class, but it must stay here. TEACHER (TALK WHEN CALLED ON)

Introduction 1.Read the procedures. 2.State a testable question. 3.Select a substance 4.State a hypothesis. 5.Give 3 pieces of background information on the substance.* 6.Give an explanation for why you chose your substance and how finding the TC50 for your substance can be important.* * Homework if not done in class today. TEACHER (TALK WHEN CALLED ON)

Get out a sheet of paper and write the following (leave enough space between each): INTRODUCTION 1.Testable question: 2.Substance: 3.Hypothesis: 4.Background information(homework): 5.Relevance. Why testing this substance can be important (homework): TEACHER (TALK WHEN CALLED ON)

Read the procedures I ONLY HAVE ENOUGH TO SHARE, DO NOT MARK ON THESE! BY YOURSELF (SILENTLY)

Discuss the following briefly in pairs 1.What is a testable question for this procedure? 2.What substance should be used? Note: Select a substance from the list. Ask me if AFTER CLASS if you want to bring in a substance from home (I have to ok it). IN PAIRS (DISCUSS WITH YOUR PARTNER)

Testable Question What is a question that we can test in this experiment (called a bioassay)? TEACHER (TALK WHEN CALLED ON)

Testable Question On your sheet of paper write: 1. Testable Question: [Your question here] TEACHER (TALK WHEN CALLED ON)

The Substance 1.You will select a substance available in the classroom for use to conduct the investigation. 2.If you want to bring in something from home, you will have to write the introduction twice (just in case) and get the substance approved by me. TEACHER (TALK WHEN CALLED ON)

The Substance On your sheet of paper write: 2. Substance: [Your substance here] TEACHER (TALK WHEN CALLED ON)

Hypothesis Most of you will use 25 grams of your substance and you will create a 1%, 10%, and 100% solution for your assay. Discuss in your pairs: For your substance, what concentration do you think will be close to the TC50 and why? IN PAIRS (TALK WITH YOUR GROUP MEMBER)

Hypothesis Phrase your hypothesis like this: My hypothesis is that [quantity] of the [manipulated variable] will result in [what you think will happen] to the [responding variable]. IN PAIRS (TALK WITH YOUR GROUP MEMBER)

Hypothesis Example My hypothesis is that at 10% concentration of dilithium crystals will result in 50% of the lettuce seeds growing half as long as the control group. IN PAIRS (TALK WITH YOUR GROUP MEMBER)

Hypothesis On your sheet of paper write: 2. Hypothesis: [Your hypothesis here] TEACHER (TALK WHEN CALLED ON)

Background Information At home, look up background information about your substance and give your source. Examples include: 1.Chemical composition 2.Boiling point/melting point 3.Ingredients 4.How this substance is typically used 5.Known health or environmental scares 6.Fire Diamond information (red = flammability, blue = health, yellow = reactivity, white = special note) IN PAIRS (TALK WITH YOUR GROUP MEMBER)

Relevance At home, answer both questions with two sentences. 1.Why is learning what concentration your substance is harming the lettuce seeds can be important? 2.If this was a LD50 experiment with an animal, how could the results of your experiment be important to know? IN PAIRS (TALK WITH YOUR GROUP MEMBER)

DON’T WORRY I have the questions printed out for you on the procedures sheets (you probably saw them already)! Just copy the information down. :3 IN PAIRS (TALK WITH YOUR GROUP MEMBER)

Work time INTRODUCTION 1.Testable question: 2.Substance: 3.Hypothesis: 4.Background information(homework): 5.Relevance. Why testing this substance can be important (homework): If you want to use a substance that you will bring in after class, talk to me now. COME IN WITH BACKGROUND INFO AND RELEVANCE TOMORROW! IN PAIRS (TALK WITH YOUR GROUP MEMBER)

Exit slip On the index card: 1.What is your substance (both if you chose you will bring in)? 2.What is your hypothesis If you want to use a substance that you will bring in after class, talk to me now. COME IN WITH BACKGROUND INFO AND RELEVANCE TOMORROW! TEACHER (TALK WHEN CALLED ON)

New sheet of paper (leave enough space between each): INTRODUCTION 1.Testable question: 2.Substance: 3.Hypothesis: 4.Background information(homework): 5.Relevance. Why testing this substance can be important (homework): TEACHER (TALK WHEN CALLED ON)

AVID PERIOD Get your things together for the student lead conferences tomorrow! BY YOURSELF (QUIET TALKING)

LAST PERSON CALLED: (ONLY) CALL ON A FRIEND FOR HELP!