Transcript Lecture #1
Chapter 1 Discovery Science Discovery science Describes natural structures and processes as accurately as possible through careful observation and analysis of data Data Are recorded observations Can be quantitative or Figure 1.24 qualitative Hypothesis-Based Science In science, inquiry that asks specific questions Usually involves the proposing and testing of hypothetical explanations, or hypotheses In science, a hypothesis Is a tentative answer to a well-framed question, an explanation on trial Makes predictions that can be tested In this case study Mimicry in king snakes is examined The hypothesis predicts that predators in non–coral snake areas will attack king snakes more frequently than will predators that live where coral snakes are present Scarlet king snake Key Range of scarlet king snake Range of eastern color snake North Carolina South Carolina Eastern coral snake Figure 1.27 Scarlet king snake Artificial Snakes To test this mimicry hypothesis Researchers made hundreds of artificial snakes, an experimental group resembling king snakes and a control group of plain brown snakes (a) Artificial king snake Figure 1.28 (b) Brown artificial snake that has been attacked After a given period of time The researchers collected data that fit a key Key Key prediction % of attacks on artificial king snakes % of attacks on brown artificial snakes Field site with artificial snakes 17% In areas where coral snakes were absent, most attacks were on artificial king snakes 83% X XX North Carolina X XX South X Carolina X X XX XXX 16% 84% Figure 1.29 In areas where coral snakes were present, most attacks were on artificial king snakes Limitations of Science Science cannot address supernatural phenomena Because hypotheses must be testable and falsifiable and experimental results must be repeatable Concept of Scale The study of life extends from the microscope scale of molecules and cells to the global scale of the entire living planet Hierarchy of Organization Molecule Organelle Cells Tissues Organ Organism Population Community Ecosystem Feedback Regulation: Negative Accumulation of an end product of a process slows that process Example: sugar breakdown generates ATP; excess ATP inhibits an enzyme near the beginning of the pathway Feedback Regulation: Positive An end product speeds up its production Example: blood clotting in response to injury Grouping Species Taxonomy (classifying life) Ursus Species Genus Family americanus (American black bear) Is the branch of biology that names and classifies species according to a system of broader and broader groups Order Class Phylum Kingdom Domain Ursus Ursidae Carnivora Mammalia Chordata Animalia Eukarya The Three Domains of Life At the highest level, life is classified into three domains: Bacteria (prokaryotes) Archaea (prokaryotes) Eukarya (eukaryotes) Eukaryotes include protists and the kingdoms Plantae, Fungi, and Animalia LE 1-15 Bacteria Archaea 4 µm 0.5 µm Protists Kingdom Fungi 100 µm Kingdom Plantae Kingdom Animalia Unifying Themes in Biology