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Chapter 1. Exploring Life. Figure 1.1 Biology is the science that focuses on life. (b) Evolutionary adaptation. (a) Order. (c) Response to the environment. (e) Energy processing. (d) Regulation. (f) Growth and development. (g) Reproduction.
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Chapter 1 Exploring Life
(b) Evolutionary adaptation (a) Order (c) Response to the environment (e) Energy processing (d) Regulation (f) Growth and development (g) Reproduction Figure 1.2 Some properties of life
2 Ecosystems 3 Communities 4 Populations 5 Organisms Figure 1.3 Exploring Levels of Biological Organization 1 The biosphere
1 µm 8Cells Cell 9Organelles Atoms 10Molecules 7Tissues 10 µm 50 µm 6Organs and organ systems
Figure 1.4 Basic scheme for energy flow through an ecosystem Sunlight Ecosystem Producers (plants and other photosynthetic organisms) Heat Chemical energy Consumers (including animals) Heat
Figure 1.5 A lung cell from a newt divides into two smaller cells that will grow and divide again 25 µm
Figure 1.6 Inherited DNA directs development of an organism Sperm cell Nuclei containing DNA Fertilized egg with DNA from both parents Embyro’s cells with copies of inherited DNA Egg cell Offspring with traits inherited from both parents
Nucleus DNA Cell A C Nucleotide T A T A C C G T A G T A (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. (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). Figure 1.7 DNA: The genetic material
EUKARYOTIC CELL PROKARYOTIC CELL DNA (no nucleus) Membrane Membrane Cytoplasm Organelles 1 µm Nucleus (contains DNA) Figure 1.8 Contrasting eukaryotic and prokaryotic cells in size and complexity
Outer membrane and cell surface CELL Cytoplasm Nucleus Figure 1.10 A systems map of interactions between proteins in a cell
A A Negative feedback Enzyme 1 Enzyme 1 B B Enzyme 2 C C Enzyme 3 D D D D D D D D D D D Figure 1.11 Negative feedback
W W Enzyme 4 Enzyme 4 Positivefeedback X X Enzyme 5 Enzyme 5 Y Y Enzyme 6 Enzyme 6 Z Z Z Z Z Z Z Z Z Z Z Z Z Z Z Z Z Z Z Figure 1.12 Positive feedback
Species Genus Family Order Class Phylum Kingdom Domain Ursusameri- canus (American black bear) Ursus Ursidae Carnivora Mammalia Chordata Animalia Eukarya Figure 1.14 Classifying life
Figure 1.15 Exploring Life’s Three Domains Kingdom Plantae consists of multicellular eukaryotes that carry out photosynthesis, the conversion of light energy to food. Bacteria are the most diverse and widespread prokaryotes, and are now divided among multiple kingdoms. Each of the rod-shapedstructures in this photo is a bacterial cell. Protists (multiple kingdoms) are unicellular eukaryotes and their relatively simple multicellular relatives. Pictured here is an assortment of protists inhabiting pond water. Scientists are currently debating how to split the protistsinto several kingdoms that better represent evolution and diversity. 4 µm 100 µm Kindom Fungi is defined in part by thenutritional mode of its members, suchas this mushroom, which absorbs nutrients after decomposing organic material. Kindom Animalia consists of multicellular eukaryotes thatingest other organisms. Many of the prokaryotes known as archaea live in Earth‘s extreme environments, such as salty lakes and boiling hot springs. Domain Archaea includes multiple kingdoms. The photoshows a colony composed of many cells. 0.5 µm
15 µm 1.0 µm Cilia of Paramecium.The cilia of Parameciumpropel the cell throughpond water. 5 µm Cross section of cilium, as viewed with an electron microscope 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. Figure 1.16 An example of unity underlying the diversity of life: the architecture of cilia in eukaryotes
Figure 1.18 Charles Darwin in 1859, the year he published The Origin of Species
Figure 1.20 Summary of natural selection Population of organisms Overproduction and struggle for existence Hereditary variations Differences in reproductive success Evolution of adaptations in the population
Figure 1.21 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.
Large ground finch Large tree finch Smallground finch Large cactus ground finch Camarhynchuspsitacula Geospiza magnirostris Greenwarbler finch Graywarbler finch Geospizafuliginosa Mediumtree finch Sharp-beaked ground finch Woodpecker finch Mediumground finch Geospiza conirostris Certhideaolivacea Certhideafusca Geospiza difficilis Camarhynchuspauper Cactusground finch Cactospizapallida Mangrovefinch Geospiza fortis Small tree finch Geospizascandens Camarhynchusparvulus Cactospiza heliobates Vegetarianfinch Seed eater Cactus flowereater Seed eater Platyspizacrassirostris Insect eaters Bud eater Ground finches Tree finches Warbler finches Common ancestor fromSouth American mainland Figure 1.23 Descent with modification: adaptive radiation of finches on the Galápagos Islands
Figure 1.24 Jane Goodall collecting qualitative data on chimpanzee behavior
Observations Questions Hypothesis # 1:Dead batteries Hypothesis # 2:Burnt-out bulb Prediction: Replacing bulb will fix problem Prediction: Replacing batteries will fix problem Test prediction Test prediction Test falsifies hypothesis Test does not falsify hypothesis Figure 1.25 A campground example of hypothesis-based inquiry
Flower fly(non-stinging) Honeybee (stinging) Figure 1.26 A stinging honeybee and its nonstinging mimic, a flower fly
Scarlet king snake Key Range of scarlet king snake Range of eastern color snake NorthCarolina SouthCarolina Eastern coral snake Figure 1.27 Geographic ranges of Carolina coral snakes and king snakes Scarlet king snake
Figure 1.28 Artificial snakes used in field experiments to test the mimicry hypothesis (a) Artificial king snake (b) Brown artificial snake that has been attacked
EXPERIMENT David Pfennig and his colleagues made artificial snakes to test a prediction of the mimicry hypothesis: that king snakes benefit from mimicking the warning coloration of coral snakes only in regions where poisonous coral snakes are present. The Xs on the map below are field sites where the researchers placed equal numbers of artificial king snakes (experimental group) and brown artificial snakes (control group). The researchers recovered the artificial snakes after four weeks and tabulated predation data based on teeth and claw marks on the snakes (see Figure 1.28). In field sites where coral snakes were present, predators attacked far fewer artificial king snakes than brown artificial snakes. The warning coloration of the “king snakes” afforded no such protection where coral snakes were absent. In fact, at those field sites, the artificial king snakes were more likely to be attacked than the brown artificial snakes, perhaps because the bright pattern is particularly easy to spot against the background. RESULTS Figure 1.29 Inquiry Does the presence of poisonous coral snakes affect predation rates on their mimics, king snakes?
Key Key % of attacks on artificial king snakes % of attacks on brown artificial snakes Field site with artificial snakes 17% In areas where coral snakeswere absent, most attackswere on artificial king snakes 83% X X X NorthCarolina X X X X X SouthCarolina X X X X X 16% X 84% In areas where coral snakes were present, most attacks were onartificial king snakes
CONCLUSION The field experiments support the mimicry hypothesis by not falsifying the key prediction that imitation of coral snakes is only effective where coral snakes are present. The experiments also tested an alternative hypothesis that predators generally avoid all snakes with brightly colored rings, whether or not poisonous snakes with that coloration live in the environment. That alternative hypothesis was falsified by the data showing that the ringed coloration failed to repel predators where coral snakes were absent.
Fromlungs Frombody Rightartium Rightartium Rightventricle Right ventricle To body To lungs Figure 1.30 Modeling the pattern of blood flow through the four chambers of a human heart