Chapter 1

1. Chapter 1 0 Biology: Exploring Life

2. 0 • A Big-Billed Bird Rebounds • Brown pelicans • Are part of the web of life in their environment

3. 0 • The brown pelicans’ proximity to humans • Has meant trouble for the species • The brown pelicans’ connection to the environment • Sets the stage for the study of biology

4. Biosphere Ecosystem Florida coast Community All organisms on the Florida coast Population Group of brown pelicans Organism Brown pelican Spinal cord Organ system Nervous system Brain Organ Brain Nerve Tissue Nervous tissue Cell Nerve cell Nucleus Atom Organelle Nucleus Molecule DNA THE SCOPE OF BIOLOGY 0 • 1.1 Life’s levels of organization define the scope of biology • Life’s structural hierarchy • Defines the scope of biology, the scientific study of life Figure 1.1

5. 0 • An ecosystem consists of all the organisms living in a particular area • As well as the nonliving environmental components • All the living organisms in an ecosystem • Make up a community

6. 0 • A population • Consists of a localized group of individuals of a species • An individual living entity • Is an organism

7. 0 • The hierarchy continues downward with • Organ systems • Organs • Tissues • Cells • Organelles • Molecules

8. 0 • 1.2 Living organisms and their environments form interconnecting webs • Ecosystems are characterized by the cycling of chemical nutrients from the atmosphere and soil • To producers to consumers to decomposers and back to the environment

9. Sun Air Inflow of light energy Loss of heat energy O2 CO2 CO2 Chemical energy Cycling of Chemical nutrients Consumers Producers Decomposers H2O Soil Ecosystem 0 • Energy flows one-way through an ecosystem • From the sun to producers to consumers and exits as heat Figure 1.2

10. 0 • 1.3 Cells are the structural and functional units of life • A cell • Is the basic unit of life

11. 0 • New properties emerge • From the complex organization of a system, such as a cell

12. Nucleus (contains DNA) Prokaryotic cell Eukaryotic cell DNA (no nucleus) Organelles 25,000  0 • Eukaryotic cells • Contain membrane-enclosed organelles, including a DNA-containing nucleus • Prokaryotic cells • Lack such organelles Figure 1.3

13. EVOLUTION, UNITY, AND DIVERSITY 0 • 1.4 The unity of life: All forms of life have common features • DNA is the genetic information • For constructing the molecules that make up cells and organisms

14. A C T A T A C C G T A G T A 0 • Each species’ genetic instructions • Are coded in the sequences of the four building blocks making up DNA’s two helically coiled chains Figure 1.4A

15. Figure 1.4B Figure 1.4C 0 • All organisms share a common set of features • Ordered structures • Regulation of internal conditions

16. Figure 1.4D Figure 1.4E 0 • Growth and development • Energy use • Response to environmental stimuli • The ability to reproduce and evolve

17. 0 • 1.5 The diversity of life can be arranged into three domains • Organisms are grouped (classified) • Into the prokaryotic domains Bacteria and Archaea and the eukaryotic domain Eukarya

18. SEM 3,250 SEM 25,000 Figure 1.5A Figure 1.5B 0 • Domains Bacteria and Archaea

19. 0 • Domain Eukarya includes • Protists (protozoans and algae, falling into multiple kingdoms) • The kingdoms Fungi, Plantae, and Animalia Kingdom Fungi 275 Kingdom Animalia Protists (multiple kingdoms) Kingdom Plantae Figure 1.5C

20. 0 • 1.6 Evolution explains the unity and diversity of life • Charles Darwin • Synthesized the theory of evolution by natural selection Figure 1.6A

21. Populations with varied inherited traits 1 Elimination of individuals with certain traits 2 Reproduction of survivors 3 0 • Natural selection is an editing mechanism • That occurs when populations or organisms, having inherited variations, are exposed to environmental factors that favor the reproductive success of some individuals over others Figure 1.6B

22. 0 • All organisms have adaptations • That have evolved by means of natural selection Killer whale Pangolin Figure 1.6C

23. THE PROCESS OF SCIENCE 0 • 1.7 Scientists use two main approaches to learn about nature • Science • Is a way of knowing • Seeks natural causes for natural phenomena

24. 0 • Discovery Science • In discovery science • Scientists describe some aspect of the world and use inductive reasoning to draw general conclusions

25. 0 • Hypothesis-Based Science • In hypothesis-based science • Scientists attempt to explain observations by testing hypotheses

26. 0 • 1.8 With hypothesis-based science, we pose and test hypotheses • Hypothesis-based science involves • Observations, questions, hypotheses as tentative answers to questions • Deductions leading to predictions, and then tests of predictions to see if a hypothesis is falsifiable

27. Observations Question Hypothesis # 1: Dead batteries Hypothesis # 2: Burnt-out bulb Prediction: Replacing batteries will fix problem Prediction: Replacing bulb will fix problem Test prediction Test prediction Test does not falsify hypothesis Test falsifies hypothesis 0 • A Case Study from Everyday Life • Deductive reasoning is used in testing hypotheses as follows • If a hypothesis is correct, and we test it, then we can expect a particular outcome Figure 1.8A

28. 100 Artificial king snakes 84% 83% 80 Artificial brown snakes 60 Percent of total attacks on artificial snakes Figure 1.8B Figure 1.8C 40 17% 20 16% 0 Coral snakes absent Coral snakes present Figure 1.8E Figure 1.8D 0 • A Case Study of Hypothesis-Based Science • In experiments designed to test hypotheses • The use of control groups and experimental groups helps to control variables

29. BIOLOGY AND EVERYDAY LIFE CONNECTION 0 • 1.8 Biology is connected to our lives in many ways

30. 0 • Biology is connected to many important issues in our lives • Environmental problems and solutions • Genetic engineering • Medicine Figure 1.9

31. 0 • Many technological advances • Stem from scientific research • The science-technology-society relationship • Is an important aspect of a biology course