The Scientific Study Of Life

1. The Scientific Study Of Life Chapter 1

2. Objectives • Outline the universal characteristics of living things • Describe the Scientific Classification System • Outline the Scientific Method as a process

3. Biology • Biology is the study of life • Living organisms have several properties and common characteristics • Exhibit order • Ability to reproduce • Ability to grow and develop

4. Living organisms have several properties and common characteristics con’t • Utilization of energy ( metabolism) • response to external environmental stimuli • Ability to adapt • Maintenance of homeostasis • Homeostasis maintains living systems in an acceptable range

6. What biologist do • Explore life from the microscopic to the global scale

7. Heirarchy of organization • Biological organization based on hierarchy or structural levels • Each level built on previous levels • Each level shows emergent properties • While is greater than the sum of the parts • Reductionism used to study complex systems • Narrow the microscope so you can understand the simpler components

8. Organization • Cells are organized in tissues, • organs, • organ systems, • individuals, • populations, • communities • and ecosystems

10. The Cell • Cell: most basic structure in living organisms, capable of carrying out all of the activities fundamental to life • Cell is the structural and functional unit of life • Robert Hooke, an English Scientist, First described and named cells in 1665. • There are two main types of cells: Prokaryotes and Eukaryotes

11. Continuity of life is based on heritable information • Cells contain chromosomes made of DNA, the substance of genes which program the cells production of proteins and transmit information from parents to offspring

12. Form follows function • Analyzing the structure provides insights into funtion

13. Organisms interact with their environment • Organisms are open systems • Exchange materials and energy with their surroundings • Two basic types of interactions • Nutrient cycling • Energy conservation • Energy flow in ecosystems is linear as organisms convert energy from ordered to unordered

15. Organisms regulate energy transformation • Obtain energy by regulated chemical reactions • Many biological processes are self-regulating • Negative feedback • Positive feedback

16. Positive and Negative Feedback • Used to regulate function in many biological systems • Prevents was of energy and biochemicals in living systems • Helps maintain homeostasis

17. Positive and Negative Feedback

18. The System • Based on information obtained the System has been modified and is much more complicated than we will take time to explain in our class. • There are now several Domains above the Kingdom Level – Bacteria, Archaea and Eukarya

19. Characteristics of Prokaryotes • bacteria • lack many of the organelles of eukaryotes • smaller • many have cell walls

20. Characteristics of Eukaryotes • plants,animals,fungi, protista • membrane bound well defined nucleus • complex organelles • cell wall only in plants

21. Prokaryotes Vs Eukaryotes

22. For our purposes we will discuss the Five Basic Kingdoms of the domain Eukarya: Monera = Bacteria Protista = unicellular eukaryotes Plantae = plants Fungi = mushrooms, slime molds, fungi Animalia = animals

24. Biologists classify organisms into groups with similar characteristics to understand the diversity of life Classification of organisms = taxonomy The system progresses from the most general to the most specific

26. Evolution provides the explanation for the diversity and unity of life • Common characteristics are the result of common ancestry • Unifies biology

28. Who will get eaten first?

29. Natural Selection • Mechanism of Evolution • Darwin tied together the observation of other to synthesize the concept of natural selection

30. Evolutionary adaptation is the product of natural selection • Adaptations are created but not filtered • Natural selection has no “direction” • There is no agenda

31. Accumulation of adaptations • Many adaptations over time can result in a new species • Geographic isolation • Populations diversify over time as they adapt to different environments

33. Evolution and Natural Selection • Accounts for the unity and diversity of organisms • Shared characteristics inherited from common ancestor • Differences due to the modifying effect of natural selection of ancestral features • Such examples of kinship connect life’s “unity in diversity” to Darwin’s concept of “descent with modification”

34. Scientific Method Science means to know in Latin Scientific Method specifies a process used to find answers there are many different approaches

35. Scientific method Scientific Process ( Method) Review accumulated scientific data Formulate hypothesis Experiment and observe to collect data Evaluate results

37. Hypotheses Facts to remember regarding hypotheses They reflect past experience with similar questions Propose multiple hypotheses whenever possible Hypotheses should be testable via scientific process Hypotheses can be eliminated, but not proven with 100% certainty

38. Hypotheses Con’t • H0 = There is no difference • Example: There will be no difference in the stalking behavior of lions born in zoos and lions born in the wild • HA = There is a difference • Example: Lions born in the wild will stalk prey more efficiently than those born in zoos.

39. Checklist • What do biologist study? • What are the properties of living organisms? • Is biology organized or random? • What is the most basic unit of life? • What are the two types of cells? • What is heritable information made of?

40. Checklist • Organisms open or closed systems? • What are the two types of interactions an organism does? • What are the two types of feedback? • How does each type work? • What are the three domains? • Which one are prokaryotic and which ones are eukaryotic? • What are the 5 kingdoms? What domain are they under?

41. Checklist • What are the characteristics of prokaryotes? Eukaryotes? • What is the taxonomic order? • What provides the explanation for the diversity and unity of life? • What is the mechanism of evolution?