1. Chapter 1: Exploring Life

2. History is a vital tool in learning about science. Louis Pastuer Charles Darwin

3. Figure 1.1

4. Biology is the science that focuses on life

5. Figure 1.3 Order Evolutionary adaptation Response to the environment Reproduction Growth and development Energy processing Regulation

6. Exploring Levels of Biological Organization 1 The biosphere 2 Ecosystems 3 Communities 4 Populations 5 Organisms

7. 8 Cells 6 Organs and organ systems 7 Tissues 10 Molecules 9 Organelles 50 µm 10 µm 1 µm Cell Atoms

8. Basic scheme for energy flow through an ecosystem Figure 1.5 Leaves take in carbon dioxide from the air and release oxygen. Animals eat leaves and fruit from the tree. Sunlight CO 2 O2O2 Cycling of chemical nutrients Leaves fall to the ground and are decomposed by organisms that return minerals to the soil. Water and minerals in the soil are taken up by the tree through its roots. Leaves absorb light energy from the sun.

9. Inherited DNA directs development of an organism Sperm cell Nuclei containing DNA Egg cell Fertilized egg with DNA from both parents Embyro’s cells with copies of inherited DNA Offspring with traits inherited from both parents Figure 1.10

10. DNA: The genetic material Nucleus DNA Cell Nucleotide A C T A T A C C G G T A T A (b) Single strand of DNA. These geometric shapes and letters are simple symbols for the nucleotides in a small section of one chain of a DNA molecule. Genetic information is encoded in specific sequences of the four types of nucleotides (their names are abbreviated here as A, T, C, and G). (a) DNA double helix. This model shows each atom in a segment of DNA. Made up of two long chains of building blocks called nucleotides, a DNA molecule takes the three-dimensional form of a double helix.

11. Contrasting eukaryotic and prokaryotic cells in size and complexity Figure 1.8 Eukaryotic cell Prokaryotic cell Cytoplasm DNA (no nucleus) Membrane Nucleus (membrane- enclosed) Membrane Membrane- enclosed organelles DNA (throughout nucleus) 1  m

12. Modern biology as an information science

13. Figure 1.13 Negative feedback A B C D C Enzyme 1 Enzyme 2 Enzyme 3 D W Enzyme 4 X D D Excess D blocks a step. (a) Negative feedback Positive feedback Excess Z stimulates a step. Y Z  Z Z Z (b) Positive feedback Enzyme 5 Enzyme 6

14. Drawers of diversity

15. Classifying life Species Genus Family Order Class Phylum Kingdom Domain Mammalia Ursus ameri- canus (American black bear) Ursus Ursidae Carnivora Chordata Animalia Eukarya

16. Exploring Life’s Three Domains (a) Domain Bacteria(b) Domain Archaea (c) Domain Eukarya 2  m 100  m Kingdom Plantae Kingdom Fungi Protists Kingdom Animalia

17. An example of unity underlying the diversity of life: the architecture of cilia in eukaryotes Cilia of Paramecium. The cilia of Paramecium propel the cell through pond water. Cross section of cilium, as viewed with an electron microscope 15 µm 1.0 µm 5 µm Cilia of windpipe cells. The cells that line the human windpipe are equipped with cilia that help keep the lungs clean by moving a film of debris-trapping mucus upward.

18. Digging into the past

19. Charles Darwin in 1859, the year he published The Origin of Species

20. Unity and diversity in the orchid family

21. Summary of natural selection Population of organisms Hereditary variations Differences in reproductive success Evolution of adaptations in the population Overproduction and struggle for existence

22. Natural selection 1 Populations with varied inherited traits 2 Elimination of individuals with certain traits. 3 Reproduction of survivors. 4 Increasing frequency of traits that enhance survival and reproductive success.

23. Form fits function

24. Descent with modification: adaptive radiation of finches on the Galápagos Islands Figure 1.22 COMMON ANCESTOR Green warbler finch Certhidea olivacea Gray warbler finch Certhidea fusca Sharp-beaked ground finch Geospiza difficilis Vegetarian finch Platyspiza crassirostris Mangrove finch Cactospiza heliobates Woodpecker finch Cactospiza pallida Medium tree finch Camarhynchus pauper Large tree finch Camarhynchus psittacula Small tree finch Camarhynchus parvulus Large cactus ground finch Geospiza conirostris Cactus ground finch Geospiza scandens Small ground finch Geospiza fuliginosa Medium ground finch Geospiza fortis Large ground finch Geospiza magnirostris Insect-eaters Seed-eater Bud-eater Insect-eaters Tree finches Ground finches Seed-eaters Cactus-flower- eaters Warbler finches

25. A campground example of hypothesis-based inquiry Observations Questions Hypothesis # 1: Dead batteries Hypothesis # 2: Burnt-out bulb Prediction: Replacing batteries will fix problem Prediction: Replacing bulb will fix problem Test prediction Test does not falsify hypothesis Test prediction Test falsifies hypothesis

26. Figure 1.23

27. A stinging honeybee and its nonstinging mimic, a flower fly Flower fly (non-stinging) Honeybee (stinging)

28. Science as a social process

29. Eleven Themes that Unify Biology