1. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings BIOLOGY 101 Scientific Study of Life Introduction to Biology

2. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings The lives of gray-headed flying foxes are closely entwined with the lives of the eucalyptus trees that form their habitat –Eucalyptus trees provide food and roosting sites for the flying foxes –Flying foxes aid in eucalyptus pollination and help disperse the resulting seeds Life in the Trees

3. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Flying foxes are becoming an endangered species, partly because of habitat destruction

4. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Biology is the scientific study of life Interactions between different kinds of organisms affect the lives of all –Recall the example of flying foxes and eucalyptus trees THE SCOPE OF BIOLOGY

5. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings A structural hierarchy of life, from molecules to ecosystems, defines the scope of biology An ecosystem consists of: –all organisms living in a particular area –all nonliving physical components of the environment that affect the organisms (soil, water) 1.1 Life’s levels of organization define the scope of biology

6. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings At the top of life’s hierarchy is the ecosystem Ecosystems include: –all the organisms in an area, which make up a community –interbreeding organisms of the same species, a population ECOSYSTEM LEVEL Eucalyptus forest COMMUNITY LEVEL All organisms in eucalyptus forest POPULATION LEVEL Group of flying foxes ORGANISM LEVEL Flying fox ORGAN SYSTEM LEVEL Nervous system ORGAN LEVEL Brain Brain Spinal cord Nerve TISSUE LEVEL Nervous tissue CELLULAR LEVEL Nerve cell MOLECULAR LEVEL Molecule of DNA Figure 1.1

7. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Organisms are made up of: –organ systems –organs –tissues –cells –molecules ECOSYSTEM LEVEL Eucalyptus forest COMMUNITY LEVEL All organisms in eucalyptus forest POPULATION LEVEL Group of flying foxes ORGANISM LEVEL Flying fox ORGAN SYSTEM LEVEL Nervous system ORGAN LEVEL Brain Brain Spinal cord Nerve TISSUE LEVEL Nervous tissue CELLULAR LEVEL Nerve cell MOLECULAR LEVEL Molecule of DNA Figure 1.1

8. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings In discovery science, scientists describe some aspect of the world and use inductive reasoning to draw general conclusions –Example: scientists have described how newborn flying foxes cling to their mother’s chest for the first weeks of life 1.2 Scientists use two main approaches to learn about nature THE PROCESS OF SCIENCE Figure 1.2

9. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings In hypothesis-driven science, scientists use the “scientific method” –They propose a hypothesis –They make deductions leading to predictions –They then test the hypothesis by seeing if the predictions come true

10. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings The main steps of the scientific method 1.3 With the scientific method, we pose and test hypotheses Observation Question Hypothesis Prediction Test: Experiment or additional observation Test does not support hypothesis; revise hypothesis or pose new one Test supports hypothesis; make additional predictions and test them Figure 1.3A

11. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Deductive reasoning is used in testing hypotheses –starts with a general explanation which leads to predictions for specific observations supporting it

12. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Experiments designed to test hypotheses must be controlled experiments Control groups must be tested along with experimental groups for the meaning of the results to be clear. –Controls are used to filter out other explanations. A control is a replica of the experiment with the independent variable omitted. The dependent variable is what is measured (like how much a plant grows from day to day). The control in human drug tests is generally a sugar pill called a placebo.

13. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings The scientific method In order to eliminate human bias most drug tests are conducted in a double blind fashion. In a double blind experiment researchers and patients do not know whether the pill given is the drug or the placebo until the trial is over.

14. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Case study: spider mimicry Pounce rate (% of trials in which spider jumped on fly) Control group (untreated flies) Experimental group (wing markings masked) Figure 1.3C Figure 1.3D

15. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Another test of the spider mimic hypothesis: wing transplants Number of stalk and attack responses by spiders Wing markings Normal spider mimic Figure 1.3E Wing waving Mimic with mimic wing transplant ControlsExperimentals Mimic with housefly wing transplant Housefly with mimic wing transplant Normal housefly

16. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Modern Biology is based on; The Cell Theory The Theory of Evolution by Natural Selection Gene Theory Homeostasis

17. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings The Cell Theory: All cells come from pre-existing cells All organisms are composed of one or more cells.

18. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Grouping organisms by fundamental features helps make the vast diversity of life manageable for study Scientists classify organisms into a hierarchy of broader and broader groups 1.4 The diversity of life can be arranged into three domains EVOLUTION, UNITY, AND DIVERSITY

19. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 1.8 Evolution

20. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Tree of Life

21. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Most classification schemes group organisms into three domains: –Domain Bacteria Figure 1.4A, B –Domain Archaea

22. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings –Domain Eukarya Figure 1.4C-F

23. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Cells

24. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Cells and Organelles

25. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Macromolecules

26. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings All organisms share a set of common features, signs of unity in life’s vast diversity –All are made of cells –All have DNA as their genetic blueprint These orchids show the variety possible within one species 1.5 Unity in diversity: All forms of life have common features Figure 1.5A

27. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings DNA is made of chemical units called nucleotides Each species has its own nucleotide sequence Figure 1.5B

28. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings DNA

29. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Central Dogma

30. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Chromosomes

31. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Cell Cycle

32. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Mitosis

33. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings The genetic information in DNA underlies all of the features that distinguish life from nonlife –Order and regulation –Growth and development –Use of energy from the environment –Response to environmental stimuli –Ability to reproduce –Evolutionary change

34. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Molecular Basis of Inheritance

35. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Scale

36. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Cells and Tissues In human body, there are more than 200 different kinds of cells. These cells make up five main type of tissue Epithelial tissue Connective tissue Blood Nervous tissue Muscle

37. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Connective Tissue Fibroblasts

38. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Epithelial tissue From The Cell 2nd ednASM & Sinauer mouth Bile duct

39. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Blood Granulocyte LymphocyteMonocyte

40. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Nervous tissue from http://www.lab.anhb.uwa.edu.au/mb140/CorePages/Nervous/Nervous.htm

41. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Muscle Smooth muscleSkeletal muscleCardiac muscle From http://www.meddean.luc.edu/lumen/MedEd/Histo/frames/h_frame7.html

42. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Charles Darwin is a central figure in biology He synthesized the theory of evolution by natural selection –A theory in science is a comprehensive idea with broad explanatory power Evolution is the core theme of biology 1.6 Evolution explains the unity and diversity of life Figure 1.6A

43. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings The theory of natural selection explains the main mechanism whereby all species of organisms change, or evolve Figure 1.6B (1) Population with varied inherited traits (2) Elimination of individuals with certain traits (3) Reproduction of survivors

44. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Model Organisms: E. coli Uses medium containing glucose, aa, salts, vitamins; Divide every 20 mins Genome contains 4.6 million base pairs; about 4000 genes Clonal populations can be selected; those resistant to penicillin

45. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 1.14 Bacterial Colonies

46. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Yeast: S. cerevisiae Eukaryotic Genome contains 12 million base pairs of DNA; 6000 genes; 16 linear chromosomes Can be grown in the lab; replicate every 2 hours grown in colonies Can be used to understand DNA replication, transcription, RNA processing, protein sorting, regulation of cell division

47. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 1.15 Electron Micrograph of Saccharomyces cerevisiae

48. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Worm: C. elegans Multicellular Understanding development Genome contains 100 million bps of DNA; 19000 genes Contain 959 cells (somatic); 1000-2000 germ cells Lineage tracing; genes of development and differentiation

49. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 1.17 Caenorhabditis elegans

50. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Plant: Arabidopsis Plant molecular biology and development Genome contains 120 million bp of DNA, 15000 genes. Can be grown in pots; mutants are available Comparisons of cellular mechanisms between plants and animals

51. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 1.19 Arabidopsis thaliana

52. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Vertebrates Xenopus laevis: frog Danio rerio: fish

53. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 1.20 Eggs of the Frog Xenopus laevis

54. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 1.21 Zebrafish

55. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Model Organisms and Applications

56. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Model Organisms and Applications

57. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Model Organisms and Applications

58. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Model Organisms and Applications

59. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Model Organisms and Applications

60. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Model Organisms and Applications

61. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Model Organisms and Applications

62. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Model Organisms and Applications

63. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 1.22 Defects in pigmentation (piebaldism) due to mutations in a gene regulate migration of melanocytes

64. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Humans and Flies Alike (Pax6 gene)

65. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Table 1.1 Prokaryotic and Eukaryotic Cells

66. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Table 1.2 DNA Content of Cells