1-1 What is the goal of Science? Investigate and understand nature Explain events in nature Make predictions
Observations *using the senses to gather/collect data Quantitative -observations based on numbers or quantities Ex.Counting/measuring 7 birds, 14 miles, 200 people Qualitative -observations based on description Ex. Color/texture blue neck, large teeth, soft cushion
The Scientific Method 1)Problem 2)Hypothesis 3)Experiment 4)Data collection 5)Conclusion
Hypothesis A possible answer to a scientific question Ex. Use hypothesis to discover how infected disease was contracted: -spread by human contact? -spread through insect bites? -spread through contaminated air/water/food? **All of these are then tested to find the correct explanation.
Variables IV = Independent: the one that is tested (only 1); on X axis. DV = Dependent: the one that is measured; on Y axis. Controls: those that remain constant/unchanged
Experimentation Controlled steps used to test the hypothesis Controlled Experiment-only 1 variable is changed and all others are kept the same. 2 Groups –Control Group: no IV tested; standard for comparing with… –Experimental Group: IV tested
Data Collection & Analysis Displayed in table/graph Analyzing data brings you to a final decision/conclusion Evidence found supports or refutes hypothesis will test correct or wrong Conclusion
What is a Theory? A well tested explanation that unites many observations (evidence builds up to make hypothesis very well supported) Can be proven wrong when new data arises to refute it. May be revised or replaced by a more useful explanation.
Studying Life What do all living things have in common? List 5 things that all living things do:
Characteristics of Living Things: 1.Made of units called cells 2.Reproduce 3.Based on universal genetic code 4.Grow and develop 5.Obtain/use materials and energy 6.Respond to environment 7.Maintain stable internal environment 8.Change over time
Metabolism -chemical reactions an organism uses to build up and break down materials -how cells acquire and use energy to grow and survive (ex. Digestion, making proteins) Homeostasis -keeping the internal conditions of an organism stable (ex. Body temperature, breathing, heart rate)
Sensing and Responding Organisms sense changes in their environment and make responses to them
Evolution - as a group all living things change over time Changes in DNA take place SLOWLY over time Changes prevail if best suited for the environment Populations evolve; not individual organisms
Biosphere Ecosystem Community Population The part of Earth that contains all ecosystems Community and its nonliving surroundings Populations that live together in a defined area Group of organisms of one type that live in the same area Biosphere Hawk, snake, bison, prairie dog, grass, stream, rocks, air Hawk, snake, bison, prairie dog, grass Bison herd Figure 1-21 Levels of Organization
Organism Groups of Cells Molecules Individual living thing Tissues, organs, and organ systems Smallest functional unit of life Groups of atoms; smallest unit of most chemical compounds Bison Nervous tissue Nervous system Brain Nerve cell Water DNA Figure 1-21 Levels of Organization continued
Microscopes- produce magnified images of structures too small for naked eye Light Microscope- produce magnified images by focusing visible light rays Up to 1000 times Live and dead organisms Electron Microscopes- produce magnified images by focusing beams of electrons Form images 1000 times smaller than those of light microscope Only dead organisms. Have no color. Why?