Chapter 1 – The Study of Life 1.1 Introduction to Biology 1.2 The Nature of Science 1.3 Methods of Science 1.1- Introduction to Biology Essential Questions: What is Biology? What are the benefits of studying Biology? What are the characteristics of living things? The Definition of Science: An accumulation of known facts. The search to explain of nature. Bio = “life” and –ology = the study of What Do Biologists Do? Study the diversity of life (Jane Goodall) Research Disease (Mary-Claire King) Develop Technology – using science to meet human needs (Charles Drew) Improve agriculture (Joanne Chory) Preserve the environment (Lee Anne Martinez Look at the picture… Answer the questions below: Name three living things. Name five nonliving things. What makes a thing living or non-living? Write a list of criteria: 1. Made of one or more cells: Single-cell organisms have everything they need to be selfsufficient. In multicellular organisms, specialization increases until some cells do only certain things. 2. Displays different levels of organization: Both molecular and cellular organization. Living things must be able to organize simple substances into complex ones. Atom Molecules Macromolecules Organelles Cells – the smallest unit of life. Tissue Organ Organ system Organism - any complete living thing. Population Community Ecosystem Biosphere 3. Grows and develops: Growth - the increase in size of an organism. Development – the process of natural changes during the life of an organism. 4. Reproduces: All living things use DNA (a genetic code) as a blueprint. All living things reproduce in one of the following ways: Sexual reproduction - Producing offspring by the joining of sex (male/female) cells. Asexual reproduction - Producing offspring (cloning) without the use of sex cells. Reproduction is not essential for the survival of individual organisms, but must occur for a species to survive. 5. Responds to their environment: A behavior is a complex set of stimulus and responses. – anything that causes a response. Response – the reaction to the stimulus. Stimulus Living things will make changes in response to a stimulus in their environment. 6. Requires energy: Living things take in energy and use it for maintenance and growth. Metabolism – any chemical process in an organism. Ex: photosynthesis Ex: digestion Ex: respiration 7: Maintains homeostasis Homeostasis – regulation of an organism’s internal conditions to maintain life. 8. Adapt to their environment: Adaptations are traits giving an organism an advantage in a certain environment. It can be: A physical trait (a body part) A physiological trait (body process) A behavior Variation of individuals is important for a healthy species. In Summary: Living Things… 1. 2. 3. 4. 5. 6. 7. 8. Are made of one or more cells Have different levels of organization Grow and develop Reproduce Responds to the environment/stimulus Use energy Maintain homeostasis Adapt to the environment Discussion Questions: Do some non-living things have some of the characteristics of life? Give an example. Name some non-living things that use energy. Name some non-living things that grow. 1.2 – The Nature of Science Essential Questions: What are the characteristics of scientific inquiry? What are the differences between science and pseudoscience? Why is scientific literacy important? The Nature of Science Science – a body of knowledge based on the study of the natural world Theory – an explanation of natural phenomenon supported by many observations and experiments over time Law – describes (but usually doesn’t explain) relationships under certain conditions What Science Does… Makes observations and draws conclusions Expands knowledge Challenges accepted theories Questions results Tests claims Undergoes peer review Science is Everyday Life Literacy – to be scientifically literate, you must combine knowledge with critical thinking skills Ethics – a set of moral principles or values. DISCUSSION QUESTION: WHY ARE THESE TWO THINGS IMPORTANT IN LIFE AND SCIENCE?? 1.3 – Methods of Science Essential Questions: What are the differences between an observation and an inference? What are the differences between a control, independent variable, and dependent variable? What are the scientific methods a biologist uses for research? Why are the metric system and SI units important? Observation v. Inference Observation – a direct method of gathering information in an orderly way. It usually involves the 5 senses! Inference – the process of combining what you know with new information to draw a logical conclusion. It involves using your brain and intuition (6th sense). Steps of The Scientific Method 1) Question or problem 2) Research problem – use dependable sources. 3) Form a hypothesis – an educated guess. If we (IV) then (DV) happens 4) Experiment to test hypothesis (use variables) controlled variable - the baseline or starting point from where you measure. This group doesn’t have the independent variable applied. independent - the variable you have control over or usually what you think will affect the dependent variable. Also known as the experimental group dependent - the variable you measure in the experiment. It is called dependent because it "depends" on what happens to the independent variable. constant – other factors that are the same in the control and experimental groups 5) Analyze data – use data tables, graphs and charts. 6) Conclusion - accept or reject hypothesis 7) REPEAT – the more times you get the same outcome the better! IV. Tools of the Scientist: the mind and senses the Scientific Method other written information microscope and other technology metrics - International System (SI Units) of measurement Let’s practice… Smithers thinks that a special juice will increase the productivity of workers. He creates two groups of 50 workers each and assigns each group the same task (in this case, they're supposed to staple a set of papers). QUESTIONS: Group A is given the special juice to drink while they work. Group B is not given the special juice. After an hour, Smithers counts how many stacks of papers each group has made. Group A made 1,587 stacks, Group B made 2,113 stacks. 1. Control Group? 2. Independent Variable? 3. Dependent Variable? 4. What should Smithers's conclusion be? 5. How could this experiment be improved? Homer notices that his shower is covered in a strange green slime. His friend Barney tells him that coconut juice will get rid of the green slime. Homer decides to check this this out by spraying half of the shower with coconut juice. He sprays the other half of the shower with water. After 3 days of "treatment" there is no change in the appearance of the green slime on either side of the shower. QUESTIONS: 6. The initial observation 7. Control Group 8. Independent Variable 9. Dependent Variable 10. What should Homer's conclusion be? Bart believes that mice exposed to microwaves will become extra strong (maybe he's been reading too much Radioactive Man). He decides to perform this experiment by placing 10 mice in a microwave for 10 seconds. He compared these 10 mice to another 10 mice that had not been exposed. His test consisted of a heavy block of wood that blocked the mouse food. he found that 8 out of 10 of the microwaved mice were able to push the block away. 7 out of 10 of the non-microwaved mice were able to do the same. QUESTIONS: 11. Control Group? 12. Independent Variable? 13. Dependent Variable? 14. What should Bart's conclusion be? 15. How could Bart's experiment be improved? Krusty was told that a certain itching powder was the newest best thing on the market, it even claims to cause 50% longer lasting itches. Interested in this product, he buys the itching powder and compares it to his usual product. One test subject (A) is sprinkled with the original itching powder, and another test subject (B) was sprinkled with the Experimental itching powder. Subject A reported having itches for 30 minutes. Subject B reported to have itches for 45 minutes. QUESTIONS: 16. Control Group? 17. Independent Variable? 18. Dependent Variable? 19. Explain whether the data supports the advertisements claims about its product. Lisa is working on a science project. Her task is to answer the question: "Does Rogooti (which is a commercial hair product) affect the speed of hair growth". Her family (mom, dad, Bart, and Maggie) is willing to volunteer for the experiment. EXIT TICKET: Describe how Lisa would perform this experiment. In your description, 1. Write a hypothesis, 2. Identify the control group, 3. Name the Independent variable 4. Name the Dependent variable. 5. List in bullets - any supplies you might need. 6. List in numbered steps the procedure you would take.