Aim: What are controlled experiments ?

Slides:



Advertisements
Similar presentations
Flowchart Designing an Experiment State the Problem Analyze Results
Advertisements

Chapter 1 The Science of Biology.
Spontaneous generation vs. biogenesis
The Birth of Experimental Biology
Life Comes From Life Experiments to disprove Spontaneous Generation.
Mystery Worms A teacher collected some beetles from a rotting log and placed them in a container of dry oatmeal in her classroom. She kept the box covered.
Biology 112 Chapter 1 Overview (Accompanies GR Chap1)
The Story of Spontaneous Generation
Early Scientists. ARISTOTLE Greek philosopher Made observations of the natural world through reasoning. Special “vital” forces brought some living things.
The Birth of Experimental Biology
UNIT I Experimental Design. I. What is Science A.Goal of Science - 1.Deals only with natural world. 2.Scientists collect and organize information in careful,
The Nature of Science 1-1 What is Science? 1-2 The Scientific Method.
Chapter 1 ( ) Before we delve into the world of BIOLOGY, we need to examine the question: What is a “FACT?” Something that can be proved or verified.
1-2 How Scientists Work Slide 1 of 32 Copyright Pearson Prentice Hall Designing an Experiment Forming a Hypothesis One early hypothesis was spontaneous.
1-2 How Scientists Work.
Slide 1 of 32 Copyright Pearson Prentice Hall 1-2 How Scientists Work Mystery Worms A teacher collected some beetles from a rotting log and placed them.
AIM: Where do Living things come from? Explain Francesco Redi’s Experiment and his contribution to science.
 Designing an Experiment  Steps: Asking questions, making observations. Forming Hypothesis (must be testable)
Where Did Life Come From?. Early thoughts about where life came from: For a long time, it seemed as if life just appeared. As far back as Aristotle (4.
Biology 112 Chapter 1 Overview (Accompanies GR Chap1) Holyoke Walsh.
The Science of Biology Biology 392. Observing the World If you are a thinker, you question things you observe and may not understand and you try to find.
And how we try to figure it out
Chapter 1 The Science of Biology. How Scientist Work Scientific Method 1. Asking a question 2. Forming a hypothesis 3. Setting –up a controlled experiment.
Redi’s Experiment – Spontaneous Generation He was trying to disprove the idea of Spontaneous Generation (or actually that flies came from maggots, which.
Chapter Asking a Question 2. Forming a Hypothesis (MUST be testable) 3. Setting up a Controlled Experiment 4. Recording and Analyzing Results.
Thinking like a scientist Galileo Gallilei and his telescope.
Redi’s Famous Experiment Hypothesis, Theory and Inference.
How Scientists Work. Key Concepts How do scientists test hypothesis? Why is it important to be able to repeat investigations?
Chapter 1 Section 1-2: How Scientists Work. Objectives Describe how scientists test hypotheses. Describe how scientists test hypotheses. Explain how a.
The Scientific Method. Recipe for Bees About 2000 years ago, a roman poet wrote these directions for producing bees: 1.Kill a bull during the first thaw.
1-2 How Scientists Work (Experimental Design)
Chapter 1 The Science of Biology The Scientific Method.
Section Outline 1–2 How Scientists Work A. Designing an Experiment
How Scientists Work Have you ever noticed what happens to food that is left in an open trash can for a few days in summer? Creatures that look like worms.
What is science?.
Scientific Method The scientific method is a series of steps taken during an experiment in order to solve a problem.
Scientific Method How Scientists Work.
Copyright Pearson Prentice Hall
What is Science? Learning about the natural world.
Biology and the Scientific Method
The Scientific Method.
The History of Science Unit 2 continued….
Spontaneous Generation
Section Outline 1–1 What Is Science? A. What Science Is and Is Not
Designing an Experiment
MIAMI BEACH SENIOR HIGH MRS DIAZ
The Story of Spontaneous Generation
Scientific Method Ch 1-3.
10T2K© The Scientific Method.
Honors Biology 1-1 What is Science?.
1.2 – Publishing and Repeating Investigations
Section 1-2 How Scientists Work
Copyright Pearson Prentice Hall
Copyright Pearson Prentice Hall
Chapter 2 – Living Things
RHP 5: Controlled Experiment
Copyright Pearson Prentice Hall
Scientific Method.
Outline 1-2 How Scientists Work
Copyright Pearson Prentice Hall
Copyright Pearson Prentice Hall
Copyright Pearson Prentice Hall
Copyright Pearson Prentice Hall
Copyright Pearson Prentice Hall
Scientific Method Section 1-2.
What is the goal of science? P. 3
The Story of Spontaneous Generation
Write what you think these words mean:
Copyright Pearson Prentice Hall
Prior to the Scientific Method:
Presentation transcript:

Aim: What are controlled experiments ? About 2000 years ago, a Roman poet wrote these directions for producing bees Why do you think individuals accepted this recipe? Recipe for Bees Kill a bull during the first thaw of winter Build a shed Place the dead bull on branches and herbs inside the shed. Wait for summer. The decaying body of the bull will produce bees

Observations seemed to indicate that living things just suddenly appeared Maggots on meat Beetles on cow dung

Common Beliefs of the Time Frogs and Turtles come from mud and rotting wood. Mice come from straw. Flies come from rotting meat. Most of these ideas remained from the time of Aristotle.

In 1668 Francesco Redi challenged these ideas. He made observations Noticed that maggots only appeared on meat a few days after flies were present He asked a question. Do flies have any thing to do with the appearance of maggots?

Hypothesis Flies produce maggots A good hypothesis is testable Redi’s next step was to test his hypothesis How do you test a hypothesis? Based on his question he developed a hypothesis. Group work: develop a plan to test a hypothesis.

A Controlled Experiment is developed to test a HYPOTHESIS The independent variable is the one that is changed by the scientist. To insure a fair test, a good experiment has only one independent variable. As the scientist changes the independent variable, he or she observes what happens. The scientist focuses his or her observations on the dependent variable to see how the organism responds to the change made to the independent variable. Give examples based on experiments you have done in the past.

Redi’s Controlled Experiment Observation: Flies land on meat that is left uncovered. Later maggots appear on meat. Hypothesis: Flies produce maggots. Experiment: Group: Explain the experiment. Independent variable is the one that changes. Beaker with cover (flies do not smell the meat) and beaker with gauze (flies can smell the meat but cannot get to it)

Conclusion: Maggots form only when flies come in contact with meat Conclusion: Maggots form only when flies come in contact with meat. Spontaneous generation did not occur.

Peer Review – Louis Pasteur’s Experiment Experiments are repeated by other scientists to ensure the results are accurate. Spontaneous Generation does not occur Broth is boiled. Broth is free of microorganisms for a year. Curved neck is removed. Broth is teeming with microorganisms. The curved neck prevented microorganisms from making their way into the flask. Once the neck of the flask was broken, microorganisms could get to the broth, where the microorganisms multiplied. Group : What did this experiment prove?

Controlled Experiment Observations Questions Hypothesis Experiment – independent and dependent variables (Procedure & Materials) Data Analysis of Data – Chart or graph Conclusion

Inquiry-Deformed Frogs Wetland Discovery Students will make a list of the questions they have about these deformed frogs, and do what is asked on the handout. HW 4 Inquiry-Deformed Frogs