1. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings PowerPoint Lectures for Biology: Concepts and Connections, Fifth Edition – Campbell, Reece, Taylor, and Simon Lectures by Chris Romero Chapter 1 Biology: Exploring Life

2. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings A Big-Billed Bird Rebounds Some core themes underlie all of biology: evolution, cells as the fundamental unit of life, a nearly universal genetic code, the relation of structure and function The brown pelican is an example of the connection between organisms and their environment

4. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings THE SCOPE OF BIOLOGY 1.1 Life’s levels of organization define the scope of biology These levels represent a hierarchy Starting with the biosphere, each level is less inclusive than the one below it

5. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings – Biosphere: all the environments of Earth that support life – Ecosystem: All the living and nonliving components of a particular environment – Community: All the living organisms in an ecosystem – Population: an interacting group of individuals of one species – Organism: An individual living entity

6. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings The hierarchy continues downward with – Organ systems – Organs – Tissues – Cells – Organelles – Molecules – Atoms

7. LE 1-1 Biosphere Ecosystem Florida coast Community All organisms on the Florida coast Population Group of brown pelicans Organism Brown pelican Organ system Nervous system Organ Brain Spinal cord Nerve Brain Tissue Nervous tissue Nucleus Cell Nerve cell Organelle Nucleus Molecule DNA Atom

8. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings 1.2 Living organisms and their environments form interconnecting webs Producers-photosynthetic organisms-use energy from the sun to produce food Consumers are ultimately dependent on producers for food Decomposers break down dead organic material, which is recycled

9. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings The dynamics of an ecosystem include two major processes: – The cycling of chemical nutrients – The one-way flow of energy, entering as sunlight and leaving as heat

10. LE 1-2 Sun Inflow of light energy Loss of heat energy Air Chemical energy Cycling of chemical nutrients Producers Consumers Decomposers Soil Ecosystem H2OH2O O2O2 CO 2

11. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings 1.3 Cells are the structural and functional units of life Cells perform all functions necessary for life – Regulate their internal environment – Take in and use energy – Respond to the local environment – Develop and maintain their complex organization – Divide to form new cells

12. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Theme of emergent property – "The whole is greater than the sum of its parts" – The combination of the parts that form a more complex organization is called a system

13. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Two basic types of cells: prokaryotes and eukaryotes – Prokaryotes are smaller and less complex than eukaryotes and lack a nucleus and other organelles – Eukaryotes are generally larger and more complex and contain a nucleus and other organelles

14. LE 1-3 Nucleus (contains DNA) Eukaryotic cell Prokaryotic cell DNA (no nucleus) Organelles 25,000 

15. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings EVOLUTION, UNITY, AND DIVERSITY 1.4 The unity of life: All forms of life have common features Genetic information within all cells is coded in DNA molecules Each DNA molecule is made up of chains of four chemical "building blocks"

16. LE 1-4a A C T A T A C C G T A G T A

17. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Other common properties of organisms: – Order – Regulation – Growth and development – Energy use – Response to the environment – Reproduction – Evolution

22. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings 1.5 The diversity of life can be arranged into three domains Scientists have identified about 1.8 million species-particular types of organisms Taxonomy classifies species into a hierarchy of increasingly broad groups

23. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Three domains are the most overarching groups: – Domain Bacteria, unicellular prokaryotes (cells that lack a nucleus) – Domain Archaea, unicellular prokaryotes – Domain Eukarya, unicellular and multicellular eukaryotes (cells with a nucleus), including protists, plants, animals, and fungi

26. LE 1-5c Kingdom Fungi Kingdom Animalia Kingdom Plantae Protists (multiple kingdoms) 275 

27. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings 1.6 Evolution explains the unity and diversity of life Charles Darwin proposed the theory of evolution by natural selection – Species evolved from ancestors through "descent with modification" – Natural selection occurs as heritable variations are exposed to environmental factors that favor the reproductive success of some individuals over others The product of natural selection is adaptation

28. LE 1-6b Population with varied inherited traits Elimination of individuals with certain traits Reproduction of survivors

30. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Video: Seahorse Camouflage Video: Seahorse Camouflage

31. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings THE PROCESS OF SCIENCE 1.7 Scientists use two main approaches to learn about nature Discovery science – Primarily describes nature through verifiable observations and measurements Hypothesis-driven science – Attempts to explain nature by studying questions drawn from observations made during "discovery science" – Hypothesis: a tentative answer to a problem or question that is being asked

32. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings 1.8 With hypothesis-based science, we pose and test hypotheses Hypothesis-based science applies the five steps of the scientific method: (1) Observations from others or results of earlier tests (2) Questions about unclear aspects of the observations: How? Why? When?

33. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings (3) Hypotheses or tentative explanations of a phenomenon Must be testable Must be falsifiable (4) Predictions developed by the use of deductive reasoning (if...then) (5) Tests of predictions to determine if the predictions are supported or falsified.

34. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings A Case Study from Everyday Life Following the scientific method to discover why a flashlight doesn't work Using deductive reasoning to test alternative hypotheses – If a hypothesis is correct, and we test it, then we can expect a particular outcome

35. LE 1-8a-1 Observations Question Hypothesis #1: Dead batteries Hypothesis #2: Burnt-out bulb

36. LE 1-8a-2 Observations Question Hypothesis #1: Dead batteries Hypothesis #2: Burnt-out bulb Prediction: Replacing bulb will fix problem Prediction: Replacing batteries will fix problem

37. LE 1-8a-3 Observations Question Hypothesis #1: Dead batteries Prediction: Replacing batteries will fix problem Hypothesis #2: Burnt-out bulb Prediction: Replacing bulb will fix problem Test prediction Test falsifies hypothesisTest does not falsify hypothesis

38. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings A Case Study of Hypothesis-Based Science Following the scientific method to test an hypothesis about the function of biological mimicry – Predict that mimicry should protect coral snakes in the areas where king snakes live – Develop a controlled experiment using artificial snakes – Summarize results confirming prediction in a graph

42. LE 1-8e Artificial king snakes Artificial brown snakes 84% 16% 17% Coral snakes absent Coral snakes present 83% 100 80 60 40 20 0 Percent of total attacks on artificial snakes

43. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings BIOLOGY AND EVERYDAY LIFE CONNECTION 1.9 Biology is connected to our lives in many ways Technology applies scientific knowledge for a specific purpose Biology and technology affect our everyday lives – Environmental problems and solutions – Genetic engineering – Medicine