2 Ch. 1.1 Intro to Biology & Characteristics of Life
3 SCIENCEThe continuous effort to discover and increase human knowledge through researchThe process of observing, explaining, and understanding our worldDoes NOT include “supernatural” explanations
4 Biology “Bio” = life “ology” = study of The study of life (organisms) Answers questions about the natural world:How they workHow they interact with the environmentHow they change over time
5 Branches of BiologyAnatomy: external & internal structures of organismsEcology: interactions between organisms and their environmentCytology: structure & function of cellsBotany: plants
6 5. Genetics: heredity, how traits pass from parent to offspring 6. Microbiology: “micro” = small, organisms seen with a microscope7. Taxonomy: classification8. Zoology: animals
7 Characteristics of Life: Made of cellsRespond to stimuli (change in enviro.)Maintain homeostasisUse energy (metabolism)Grow and developReproduceChange through time (evolution)
8 Homeostasis Stable internal conditions Ex: Temperature Water intake Ex: ThermostatWater intakeFood intakepH
9 MetabolismSum of all chemical rxns that take in & transform E & materials from the environmentPhotosynthesis: converts light E into chemical ECellular Respiration: converts organic cmpds into usable E (ATP)
15 Unity= all living things have features in common The genetic code; the heredity info. in DNAContain organelles; cellular structures that carry out specific functions“Tree of Life”; has 3 main branches called domains and 6 major categories called kingdoms
17 2. Interdependence of Organisms Organisms interact with each other and the living worldArea of science known as EcologyEcosystems are communities of living species & their physical environment
18 1. Can you name some parts of an ecosystem. 2 1. Can you name some parts of an ecosystem? 2. How have humans affected the environment?
19 3. Evolution of Life Populations of living organisms change over time Descent with modificationOccurs by natural selection; organisms with more favorable traits survive a changing environment and reproduce more successfully.Adaptations are traits that improve an organisms chance of survival.
20 Ch.1.3 The Scientific Method How problems are solved!Scientists use controlled methods to collect observable evidence to answer questions about natural phenomenaYouTube - Scientific Method MTV
21 Steps of the Scientific Method 1. Define the problem.2. Collect information.Qualitative vs. quantitative3. Form a hypothesis.a statement that can explain a scientists observations and dataMust be testableEducated guess that can be proven FALSEWritten as an “if-than” statement
22 4. Test the hypothesis.Controlled experiments test variables by comparing a control group with an experimental group.The independent (manipulated) variable is the one that is changed by the scientistThe dependent (responding) variable changes in response to the change made to the ind. variable
23 Hypothesis ExamplesIf skin cancer is related to ultraviolet light , then people with a high exposure to uv light will have a higher frequency of skin cancer.If leaf color change is related to temperature , then exposing plants to low temperatures will result in changes in leaf color.In the statements above the dependent variable is blue and the independent variable is red.
24 7. Report research methods & findings. 5. Observe & record data.6. Draw conclusions.Support or refute hypothesisA theory may be formed- a collection of ideas, hypotheses, laws, and predictions which have been successfully tested, but are subject to modification when facts or experiments demand it.7. Report research methods & findings.Scientific journalsLab reports
27 Presenting Scientific Findings Tables- used to organize data
28 Graphs are used to visually represent data Bar graphs- illustrate comparisonsLine graphs- recognize patterns or trendsPie graphs- represent percentagesTitle of graph should include dependent and independent variablesY-axis has the dependent variableX-axis has the independent variable
30 (pg. 21, parts of the microscope) MicroscopesLight Compound Microscope (LM):used to see small organisms and cellstransparent specimen is mounted on glass slideLight passes through the specimen(pg. 21, parts of the microscope)
31 Electron MicroscopesUse a beam of electrons to produce an enlarged image of a specimenTransmission electron microscope (TEM)-electrons sent through a thin specimencannot view living specimens200,000 x magnification
32 Scanning electron microscope (SEM) electrons pass over specimen producing a 3D image100,000 x magnificationcannot view living organisms
33 Units of MeasurementScientists use one system of measurement, the metric system( SI system)Decimal system based on powers of 10SI has 7 base units