The Scientific Process

Transcription

1 The Scientific Process

2 Before we begin. What does science mean to you? How would you define life to a young child? Do you believe there is life elsewhere in the universe? Why or why not? List the steps of the scientific method as you remember them.

3 What is biology? What is the value of biology? The study of life! Through the study of biology, we can: control disease improve health develop better foods conserve natural resources understand our environment

4 How do we study biology? 1. Observational Ecology/nature 2. Controlled Study experiments in lab 3. Computer Models - simulations ed.com/talk/ podcast/2007 /None/David Gallo_ p.mp4

5 The Nature of Science There is no universal method used by all scientists There is a logical way of thinking found in all scientific experiments We call this the scientific method

6 The Scientific Method 1. Observation 2. Ask a Question 3. Hypothesis 4. Experimentation 5. Results/Collect Data 6. Analyze and Conclude 7. Repeat and Share

7 Biology-Concepts/section/10.3/

8 USw_jg/symbiosis

9 Generate some questions! What types of questions can you generate after looking at the pictures? Ask a Question???? Write two questions about the observations you made while looking at the picture

10 How do scientists come up with questions? Curiosity- Jane Goodall studied chimpanzees in the Gombe Forest in Tanzania for decades; she even lived along them in their natural habitat. Through continual observation, she started recognizing and learning their behaviors, interactions, and group dynamics. This created a plethora of research papers and changed the way people perceived these magnificent creatures. She is now one of the most successful female scientists in history. ewpure. com/pm cnwjpix p8?start= 0&end=0

11 Skepticism- scientists don t believe everything they are told. Openness to new ideas- keep an open mind about how the world works. Intellectual Honesty- after duplicating the results, a good scientist will consider the possibility that the new results may be accurate, even if this means that the hypothesis might be wrong. wpure.co m/snuz4 OE6vCk? start=0&e nd=0

12 Imagination and Creativity- constantly coming up with new ideas and questions. Many of the new questions come from previous research, building on something that is already there.

13 A hypothesis must be: Writing a Hypothesis! testable - can be tested tentative - can change falsifiable - can be shown to be incorrect Provides a possible answer to your question Written in if..., then because format Do not use personal pronouns in your hypothesis! Can be used to make predictions about the experiment

14 Turn the question into a hypothesis! Directions: Write a hypothesis for the question and predict why you think that will happen. Question How does the amount of sunlight affect the growth of a plant? If then because.

15 What questions can be answered by science? Do excessively high temps cause people to behave immorally? Do humans communicate through chemical signals called pheromones? Is walking under a ladder bad luck? Do cactus spines prevent animals from eating the cactus?

16 Experiment Designed to pinpoint cause and effect relationships. Independent variable = The tested variable, YOU control it, YOU manipulate it. Who controls it? I DO! Example: the amount of fertilizer each plant receives

17 You need a comparison to determine the effects of your independent variable The experimental group: the group that receives the experimental treatment. Example: the plant that receives fertilizer The control group: does not receive any experimental treatment. Example: the plant that receives no fertilizer

18 Dependent variable = The effect/results, it depends on the IV. Dependent = data Ex growth of each plant Constants/controlled variables = factors kept the same in all groups Ex soil, amount of water, type of plants, etc

19 Practice: Identify the parts of an experiment in the example. A scientist wants to determine if vitamins will affect the growth of mice. She gives one group of mice a normal mouse diet, and the second group receives a normal diet supplemented with daily vitamins. The scientist then measures the weight and length of each mouse every week for 10 weeks. The mice live in the same environments and have access to the same water. Independent Variable: Dependent Variable: Experimental Group: Control Group: Constants/Controlled Variables:

20 Results/Data Collection Data: information gathered during an experiment. Qualitative Data Descriptive data Ex behaviors, color Quantitative Data Numerical data Weight, percent, count Data is organized into tables and graphs. Use the metric system for all quantitative measurements

21 Analysis & Conclusion Scientists analyze their results/data. Use statistics (mathematical tools) to help determine if their research is significant or not. Determine if hypothesis was supported or not supported.

22 Repeat & Share Results Experiment must be repeated by other scientists to verify results and add validity Removes bias (personal beliefs that can affect interpretation of results) Results can be published in a scientific journal

23 What about the questions that cannot be studied experimentally or directly measured? What was the Earth s climate like 60 million years ago? Does smoking cause lung cancer in humans?

24 Is it a theory or a law? Theory Law

25 Theory Broad explanation for a wide range of observations. Explains WHY something happens. Examples: theory of natural selection, germ theory, and the cell theory.

26 Scientific Law Describes what nature does under certain conditions. Describes WHAT will happen. Often mathematically supported. Example- Law of Gravity, Law of Conservation of Matter

27 Both Can be used to make predictions Supported by a large amount of experimental data. Widely accepted by scientists. Can be revised. pure.com/l qk3tkugn BA?start=0 &end=0

28 The Metric System

29 When we collect data in science, the metric system is used. Based on the power of 10. French came up with it. Every country uses it, except ours Measure Base Unit Equals about Length 1 Meter 3.28 feet (ft.) Mass 1 Gram Weight of a paperclip Volume 1 Liter Just less than 3 cans of soda. Temperature 0 Celsius Snow!

30 Common conversions: 1 inch= 2.54 cm 1 kg= 2.2 lbs 1 L= 1L = 1.06 quarts 1 km =.62 miles 1 ml = 1 cm 3 1 m = 3.28 feet 1 mile= 5,280 ft = m F o = (9/5 X C o ) + 32 C o = 5/9 X (F o - 32) K = C o + 273

31 Mnemonic Device King Henry Died By Drinking Chocolate Milk Base Unit: Meter Gram Liter

32 Conversion Stairs/Ladder

33 Practice!

34 General Rules for Graphing 1. Always label the X and Y axis. a.x- horizontal and is also the Independent Variable (IV), first column in data table Y b.y- vertical and is also the Dependent Variable (DV), second column in data table c. Include units (m, L, mg, etc) 2. Create a comprehensive title that explains your graph. a. Ex The Effects of Sunlight on Plant Growth (0,0) X

35 General Rules for Graphing 3. Increments/Scale a. Create a clean, even scale. Example- 2, 4, 6, 8, 10, NOT 2, 5, 6, 10, 17, 20 b.always start at 0 (where X and Y axes intersect) 4. Always graph in pencil. 5. Create a key if there are multiple sets of data. a. Use color coding or different patterns.

36 Histograms Depicts the number of events/frequency within certain ranges. Bars touch The distribution of the number of flowers per flower head in a population of red clover, Trifolium repens

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38 Bar Graphs Depicts measurements in separate categories. Can be used to compare data

39 Look at the bar graph and describe, in words, what you see.

40 Line Graphs Show changes over time. Can be used to compare data

41 Make a line graph with the data below The heating of a pot of water on a stove.

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43 Statistics The collection and classification of numerical data Used to analyze and compare data Common statistical tools: Mean the average (add up data points, divide by number of data points) When the mean is in the middle of the data = Normal distribution/bell curve Normal Distribution

44 Practice What is the mean height of the bean plants?

45 Probability Can be written as a fraction, a decimal, or a percent Example- chance of getting heads when you toss a penny. ½, 50%,.5 Must have a large sample size Everyone flip a coin 10 times and record heads versus tails.

46 Practice Problem You are in a forest and count 200 pine trees and notice that 40 of those trees have pine cones. What is the probability that the next pine tree you come across will have pine cones?

47 40/200=.20 Answer

48 Now let s read about John Snow and how he used the scientific process to build upon his hypothesis!

49 Technology in Science Technology is the application of science for practical purposes

50 Common types of technology used in Biology Microscopes: Compound Light, Dissecting Scope, Scanning Electron (SEM), and Transmission Electron (TEM). Medical Imaging: X-rays: observing the skeleton. MRI s- uses a strong magnetic field to produce a cross section image of a part of the body. Shows the soft and dense tissues in detail. Models- physical replicas, such as a heart or brain. Computer Models- computer have allowed scientists to take research to a whole new level. Can predict how fast and far the flu virus can spread in a city. The entire human genome has been figured out. The Human Genome Project was completed in April of 2003.

51 Molecular Genetics- the study and manipulation of DNA on a molecular level. It s used to study evolution, ecology, biochemistry, anatomy, etc.

52 Biotechnology- the use and application of living things and biological processes. Using microorganisms to make bread and cheese. DNA testing to free people wrongly accused of crimes. Stem Cell research

53 Cloning Dolly the sheep in Genetic screening Allows us to analyze the DNA of our offspring, and to see if there are any potential disorders or diseases.

54 There are many benefits, as well as biological risks, and is debated frequently Almost all domestic plants and animals are the result of selective breeding, where humans have manipulated their DNA.

55 Transgenic- organisms that have genes from more than one species, or have altered copies of their own genes.»examples: Glow in the dark mouse Genetically Modified Foods / AKA GMO s (corn, canola, soy). Transgenic bacteria can make human insulin to treat people with diabetes.

56 Basic unit of matter Layer around Earth where life exists Group of atoms bonded together The community plus the abiotic environment Basic unit of life bone cell Group of similar cells bone tissue Group of tissues - femur All the populations in a certain area Group of same species in same place Organs that work together skeletal system An individual