Presentation Transcript

1. Chapter 1: Introduction to Science and Exploring Life
2. spontaneous generation/biogenesis Early Views of life
3. Idea was challenged by scientist Francesco Redi in 1698. Designed an experiment where 3 jars contained meat. It was implied that flies were the source of the maggots which lead to the theory of Biogensis (life from preexisting life) The Redi Experiment
4. -Made ofCells. -The Cell is the basic unit of life-is self contained and possesses a barrier (membrane) which separates itself from the environment. -The cell is the lowest level of organization that can perform all activities required for life -Two types of organisms. Unicellular - One celled organism (Uni=1) Multicellular - Many cells (Multi=”many”) PROPERTIES of LIFE
5. Living Things mustReproduce. -Must be able to create more of it’s own kind Two types of reproduction: Sexual - Two parent organisms combine genetic material to produce the offspring. Asexual - When a single organism can divide or “bud” to create it’s offspring without another of it’s species. PROPERTIES of LIFE
6. Living things have genetic material Instructions for making all the bodies proteins Located in the nucleus (eukaryotes) or nucleiod region (prokaryotes) DNA is inherited by offspring from their parents DNA controls the development and maintenance of organisms PROPERTIES of LIFE
7. Living things must Grow & Develop. Growth refers to two processes. -Increase in the number and size of cells. Development refers to changes in the organism which occur through it’s life-span, inc. cell differentiation, aging, organ development PROPERTIES of LIFE
8. Living things obtain & use energy. Energy is used by all living things for growth, development & reproduction. PROPERTIES of LIFE
9. -Living things must Respond (or react) to their environment in some way. -Something which causes an organism to react is known as a Stimulus (stimuli). -Most responses are geared for maintaining Homeostasis. Homeostasis is a process where an organism maintains a stable internal environment so life can continue. Some examples include temperature, pH, and water content of the cell. PROPERTIES of LIFE
10. Accumulation of an end product of a process slows that process Feedback Regulation: Negative
11. Feedback Regulation: Positive An end product speeds up its production
12. Hierarchy of Organization Biosphere 9Organelles 8Cells Molecules Ecosystems Communities 7Tissues Atoms Populations 6Organs and organ systems Organisms
13. Unifying Themes in Biology Evolution~ biology’s core theme; differential reproductive success Emergent Properties~ hierarchy of life, sum is greater than each part The Cell~ all organism’s basic structure Heritable Information~ DNA Structure & Function~ form and function Environmental Interaction~ organisms are open systems Regulation~ feedback mechanisms Unity & Diversity~ universal genetic code Scientific Inquiry~ observation; testing; repeatability Science, Technology & Society~ functions of our world
14. 1) Science has principles- explain the natural world, gather evidence, science is a process 2) Characteristics of Science- conclusions are reliable (tentative), non dogmatic, provides evidence only 3)Science exists in a cultural context- human endeavor, science corrects itself Nature of Science
15. • Inductive Reasoning- "bottom up" approach move from a set of specific observations to general conclusions EX: Cells are observed in organisms x, y, and z, therefore all animals have cells. (Cell Theory) • Deductive Reasoning- "top-down" approach flows from general to specific EX: If all organisms have cells and humans are organisms, then humans should have cells Science Discovery
16. Hypothesis based off observation Independent & dependent variables Control group/experimental group/ constants Random sampling/Large sample size (n) Repeated – multiple trials (3) Graphs/Data Table/Calculations Analyze results (statistically)/Conclusions/ Describe expected outcomes NOTE: Can’t ignore or rule out data which do not support the hypothesis Good Experimental Design
17. -independent variable is the one that is changed by the scientist. -dependent variable is observed to see how it responds to the change made to the independent variable. What’s being measured. -controlled variables (constants)versus control group Variables
18. -Inquiry that asks specific questions -Usually involves the proposing and testing of hypothetical explanations, or hypotheses -Hypothesisis a tentative answer to a well-framed question, an explanation on trial -Makes predictions that can be tested -Usually expressed as an: If…., then …. Statement Hypothesis-Based Science
19. a question, "Does temperature affect fermentation?" a conditional statement, "Temperature may affect fermentation." an “If, then”statement, "If fermentation rate is related to temperature, then increasing the temperature will increase gas production. an “as” statement, “As temperature increases, as production through fermentation will also increase How to write a hypothesis The format of a hypothesis includes the independent and dependent variable (what is to be manipulated and what is to be observed). Writing A Hypothesis
20. Quantitative- analysis of numerical data(measure, count, etc) Qualitative- analysis of data such as words (e.g., from interviews), pictures (e.g., video), or objects (e.g., an artifact). Data Collection- recorded observations
21. Graphing -Title - Units Labeled - IV (X) and DV (Y) - Proportional Increments - Points plotted - Label if more than one line
22. Line versus Bar Graph Line Graph- Change over time Bar Graph/Histagram- Comparing Data Sets
23. Extrapolation Analysis of data is used to make predictions
24. Hypothesis -Explanation to specific question -Prediction -Educated guess -Tested by experiment or continued observation -Can be disproven, but not can’t proven to be true Theory -Summarizes group of hypothesis supported by repeated testing -Broader in scope -New hypotheses can be generated from it -Supported by massive body of evidence -Ex. Big Bang Theory Scientific Law -Statement of fact -Explains things, but doesn’t describe them -Generally accepted to be true and universal -Basis for scientific method -Ex. Law of Planetary Motion Comparisons