1. Introduction to Biological Concepts and Research Chapter 1

2. 1.1 What Is Life? Characteristics of Living Systems  Organized in a hierarchy Each level with its own emergent properties  Contain chemical instructions Govern structure and function  Engage in metabolic activities

3. 1.1 (cont.)  Energy flows through; matter cycles  Compensate for changes in external environment  Reproduce and undergo development  Populations change from one generation to the next

4. Hierarchy of Living Systems (1)  Cells Lowest level of organization that is alive  Organisms Unicellular or multicellular  Populations Groups of organisms of the same kind, living together in the same area

5.  Community All populations living in an area  Ecosystems Include communities that interact through their shared physical environment  Biosphere The highest level Includes all Earth’s ecosystems Hierarchy of Living Systems (2)

6. Information Flow  Living organisms have complex structures Established by instructions coded in DNA  Information in DNA is copied into RNA Guides production of protein molecules  Proteins carry out most activities of life

7. Deoxyribonucleic Acid (DNA) Fig. 1-3, p. 3

8. Information Flow Fig. 1-4, p. 4

9. Metabolism  The activity of obtaining and using energy Maintenance Growth Reproduction  Two primary metabolic processes Photosynthesis Cellular respiration

10. Metabolism Fig. 1-5, p. 4

11. Energy and Matter  Energy Flows through the hierarchy of life Eventually released as heat, which cannot be used by living systems  Matter Recycled within the biosphere

12. Energy Flow and Nutrient Recycling Fig. 1-6, p. 5

13. Compensation for Change  Cells and organisms use receptors to detect changes in environment  Triggers a compensating reaction that allows the organism to survive

14. Reproduction and Development  Organisms reproduce  Offspring develop into mature, reproductive adults

15. Evolution  Populations undergo biological evolution as generations replace one another over time

16. 1.4 Biological Research  Biologists conduct basic and applied research using the scientific method  Research includes collecting observational and experimental data  Hypotheses may be tested with controlled experiments  Or, a null hypotheses may be used to evaluate observational data

17. 1.4 (cont.)  Model organisms may be used to study fundamental biological processes  Molecular techniques have revolutionized biological research  Scientific theories are ideas that have withstood the test of time

18. Basic and Applied Research  Basic research advances our knowledge of living systems  Applied research solves practical problems

19. Data  Observational data describe biological organisms or the details of biological processes  Experimental data describe results of an experimental manipulation

20. Hypotheses  Working explanations developed by scientists about the relationships between variables  Scientific hypotheses must be falsifiable

21. Experiment  A well-designed experiment Considers alternative hypotheses Includes control treatments and replicates

22. Modern Techniques  Model organisms Easy to maintain in the laboratory Subjects of much research  Molecular techniques Manipulation of specific genes in the laboratory Allow detailed analysis of DNA of many species

23. A Scientific Theory  A set of broadly applicable hypotheses Completely supported by repeated tests under many conditions and different situations  Theory of evolution by natural selection Explains how life evolved through natural processes Central importance to biology