Biology Introduction

 Understand your world  Make informed decisions  Self  Family  Medical  Diet  Make informed votes  Understand significance of accomplishments

 Bios = life  ology = study of  Biology = study of life

 Organization  Atom  Molecule  Cell  Tissue  Organ  Organ system

 Organization (cont.)  Multicelled organism  Population  Community  Ecosystem  Biosphere

 Acquire energy  Autotrophs  Heterorophs  Metabolize  Maintain homeostasis

 Grow  Reproduce  Respond  Adapt

 Taxonomy—ID and organize into logical groups  Nomenclature—name organisms  Binomial nomenclature (Genus, species)  Homo sapiens  Canis lupus  Felis concolor

 Domain Eukarya  KingdomAnimalia  PhylumArthropoda  ClassInsecta  OrderLepidoptera  FamilyDanaidae  GenusDanaus  Speciesplexippus Monarch Butterfly

 Eubacteria  Archaebacteria  Eukarya  Kingdom Protista  Kingdom Fungi  Kingdom Plantae  Kingdom Animalia

 Gather information about the world  Do it objectively  Explain the natural world using rules or patterns in the natural world  Explanations that are testable  Can use information for prediction  No conclusion drawn in science is final!  However, can say many things with high probability

 Observation  Hypothesis  Test  Analyze & Interpret  Repeat  Theory

 Control Group  Standard of Comparison  Identical to testing group other than the variable being tested  Sampling Error  Certain amount of error in any study  Try to minimize by taking large sample sizes

 Observation: Some students fall asleep in Dr. Bern’s class  Hypothesis: Dr. Bern is the most boring Biology instructor  Test: Count number of sleeping students in Dr. Bern’s and Mr. Harnden’s classes  Results: 3/48 Students sleeping in Dr. Bern’s class, 4/48 students sleeping in Mr. Harnden’s class  Repeat: Count sleeping students in Dr. Bern’s and Ms. Henderson’s classes  Results: 3/48 students sleeping in Dr. Bern’s class, 2/48 students sleeping in Ms. Henderson’s  Analysis: 4% of students sleep in Ms. Henderson’s class, 6% in Dr. Bern’s, 8% in Mr. Harnden’s. There is a 3% margin of error.  Conclusion: Student’s sleep in Dr. Bern’s class at the same rate as other Biology instructors  Theory: Whether or not students fall asleep in class doesn’t depend on the instructor

 Can we use viruses that attack bacteria (bacteriophages) to fight infections?

 Hypothesis - Bacteriophages can protect mice against infectious bacteria  Prediction - Mice injected with bacteriophages will not die as a result of bacterial injection

 Experimental group  Inject with bacteria and bacteriophage  Control group  Inject with bacteria and saline

 Experimental group All mice lived  Control group All mice died  Conclusion - Bacteriophage injections protect mice against bacterial infections

 Prediction - Bacteriophage injections will be more effective treatment than single dose of the antibiotic streptomycin  Test - Mice injected with bacteria, then with saline, streptomycin, or bacteriophage

 With 2nd injection:  Bacteriophage - 11 of 12 mice lived  60 mg/gm streptomycin - 5 of 12 lived  100 mg/gm streptomycin - 3 of 12 lived  Saline - all mice died  Conclusion - Bacteriophage treatment can be as good or better than antibiotic

 Limited to our knowledge and understanding of the natural world  Cannot answer philosophical, moral, or ethical questions  Limited by man’s falibility