Chapter 1:Exploring Life Themes in the Study of Biology The Process - PowerPoint Presentation

Chapter 1:Exploring Life Themes in the Studyof Biology The Processof Science Biology andEveryday Life Evolution, the Core Theme of Biology

THEMES IN THE STUDY OF BIOLOGY © 2012 Pearson Education, Inc.

1.1 All forms of life share common properties Biology is the scientific study of life.Properties of life includeOrder—the highly ordered structure that typifies life,Reproduction—the ability of organisms to reproduce their own kind,Growth and development—consistent growth and development controlled by inherited DNA,Energy processing—the use of chemical energy to power an organism’s activities and chemical reactions, © 2012 Pearson Education, Inc.

1.1 All forms of life share common properties Response to the environment—an ability to respond to environmental stimuli,Regulation—an ability to control an organism’s internal environment within limits that sustain life, andEvolutionary adaptation—adaptations evolve over many generations as individuals with traits best suited to their environments have greater reproductive success and pass their traits to offspring. © 2012 Pearson Education, Inc.

Figure 1.1 (1) Order (2) Reproduction (3) Growth and development (4) Energy processing (7) Evolutionary adaptation (6) Regulation (5) Response to the environment

1.2 In life’s hierarchy of organization, new properties emerge at each level Biological organization unfolds as follows:Biosphere—all of the environments on Earth that support life,Ecosystem—all the organisms living in a particular area and the physical components with which the organisms interact,Community—the entire array of organisms living in a particular ecosystem,Population—all the individuals of a species living in a specific area, © 2012 Pearson Education, Inc.

1.2 In life’s hierarchy of organization, new properties emerge at each level Organism—an individual living thing,Organ system—several organs that cooperate in a specific function,Organ—a structure that is composed of tissues and that provides a specific function for the organism,Tissues—a group of similar cells that perform a specific function,Cells—the fundamental unit of life, © 2012 Pearson Education, Inc.

1.2 In life’s hierarchy of organization, new properties emerge at each level Organelle—a membrane-bound structure that performs a specific function in a cell, andMolecule—a cluster of small chemical units called atoms held together by chemical bonds. © 2012 Pearson Education, Inc.

Biosphere Madagascar Ecosystem: Forest inMadagascar Community:All organisms inthe forest Population: Group of ring-tailed lemurs Organism: Ring-tailed lemur Organ system: Nervous system Organ: Brain Tissue: Nervous tissue Nerve Spinal cord Brain Organelle: Nucleus Cell: Nerve cell Nucleus Atom Molecule: DNA

1.2 In life’s hierarchy of organization, new properties emerge at each level Emergent properties are new properties that arise in each step upward in the hierarchy of life,from the arrangement and interactions among component parts. 0 © 2012 Pearson Education, Inc.

1.4 Living organisms interact with their environment, exchanging matter and energy Living organisms interact with their environments, which includeother organisms andphysical factors.In most ecosystemsplants are the producers that provide the food,consumers eat plants and other animals, anddecomposers act as recyclers, changing complex matter into simpler mineral nutrients. © 2012 Pearson Education, Inc.

1.4 Living organisms interact with their environment, exchanging matter and energy The dynamics of ecosystems include two major processes:The recycling of chemical nutrients from the atmosphere and soil through producers, consumers, and decomposers back to the environment.The one-way flow of energy through an ecosystem, entering as sunlight, converted to chemical energy by producers, passed on to consumers, and exiting as heat. © 2012 Pearson Education, Inc.

Ecosystem Sunlight CO 2 Heat Chemical energy (food) Producers (such as plants) Water and minerals taken up by tree roots Cycling of chemical nutrients Decomposers (in soil) Consumers (such as animals) CO 2 O 2 O 2

EVOLUTION, THE CORE THEME OF BIOLOGY © 2012 Pearson Education, Inc.

1.5 The unity of life is based on DNA and a common genetic code All cells have DNA, the chemical substance of genes.Genesare the unit of inheritance that transmits information from parents to offspring,are grouped into very long DNA molecules called chromosomes, andcontrol the activities of a cell. © 2012 Pearson Education, Inc.

1.5 The unity of life is based on DNA and a common genetic code A species’ genes are coded in the sequences of the four building blocks making up DNA’s double helix.All forms of life use essentially the same code to translate the information stored in DNA into proteins.The diversity of life arises from differences in DNA sequences. © 2012 Pearson Education, Inc.

Figure 1.5 A T T C C G G C T A A T G C A G C G C A T

1.6 The diversity of life can be arranged into three domains We can think of biology’s enormous scope as having two dimensions.The “vertical” dimension is the size scale that stretches from molecules to the biosphere.The “horizontal” dimension spans across the great diversity of organisms existing now and over the long history of life on Earth. © 2012 Pearson Education, Inc.

1.6 The diversity of life can be arranged into three domains Diversity is the hallmark of life.Biologists have identified about 1.8 million species.Estimates of the actual number of species ranges from 10 to 100 million.Taxonomy names species and classifies them into a system of broader groups. © 2012 Pearson Education, Inc.

1.6 The diversity of life can be arranged into three domains The diversity of life can be arranged into three domains.Bacteria are the most diverse and widespread prokaryotes.Archaea are prokaryotes that often live in Earth’s extreme environments.Eukarya have eukaryotic cells and includesingle-celled protists andmulticellular fungi, animals, and plants. © 2012 Pearson Education, Inc.

Figure 1.6 Domain Bacteria Domain Archaea Domain Eukarya Bacteria Archaea Protists (multiple kingdoms) Kingdom Fungi Kingdom Animalia Kingdom Plantae

1.7 Evolution explains the unity and diversity of life The history of life, as documented by fossils, is a saga of a changing Earth billions of years old andinhabited by an evolving cast of life forms.Evolution accounts for life’s dual nature ofkinship anddiversity. © 2012 Pearson Education, Inc.

Figure 1.7B

1.7 Evolution explains the unity and diversity of life In 1859, Charles Darwin published the book On the Origin of Species by Means of Natural Selection, which articulated two main points.1. A large amount of evidence supports the idea of evolution, that species living today are descendants of ancestral species in what Darwin called “descent with modification.”2. Natural selection is a mechanism for evolution. © 2012 Pearson Education, Inc.

1.7 Evolution explains the unity and diversity of life Natural selection was inferred by connecting two observations.Individuals in a population vary in their traits, many of which are passed on from parents to offspring.A population can produce far more offspring than the environment can support. © 2012 Pearson Education, Inc.

Figure 1.7C Elimination of individuals with certain traits Reproduction of survivors Population with varied inherited traits 1 3 2

1.7 Evolution explains the unity and diversity of life From these observations, Darwin inferred that those individuals with heritable traits best suited to the environment are more likely to survive and reproduce than less well-suited individuals,as a result of this unequal reproductive success over many generations, an increasing proportion of individuals will have the advantageous traits, andthe result will be evolutionary adaptation, the accumulation of favorable traits in a population over time. © 2012 Pearson Education, Inc.

Ground pangolin Killer whale

THE PROCESS OF SCIENCE © 2012 Pearson Education, Inc.

1.8 Scientific inquiry is used to ask and answer questions about nature The word science is derived from a Latin verb meaning “to know.” Science is a way of knowing.Scientistsuse inductive reasoning to draw general conclusions from many observations anddeductive reasoning to come up with ways to test a hypothesis, a proposed explanation for a set of observations.The logic flows from general premises to the specific results we should expect if the premises are true. © 2012 Pearson Education, Inc.

1.8 Scientific inquiry is used to ask and answer questions about nature How is a theory different from a hypothesis? A scientific theory ismuch broader in scope than a hypothesis,usually general enough to generate many new, specific hypotheses, which can then be tested, andsupported by a large and usually growing body of evidence. © 2012 Pearson Education, Inc.

1.9 Scientists form and test hypotheses and share their results We solve everyday problems by using hypotheses.A common example would be the reasoning we use to answer the question, “Why doesn’t a flashlight work?”Using deductive reasoning we realize that the problem is either (1) the bulb or (2) the batteries.Further, a hypothesis must betestable andfalsifiable.In this example, two hypotheses are tested. © 2012 Pearson Education, Inc.

Test falsifies hypothesis. Revise hypothesis orpose new one. ObservationQuestion Hypothesis 1: Dead batteries Hypothesis 2: Burned-out bulb Prediction: Prediction: Replacing batteries will fix problem. Replacing bulb will fix problem. Experiment: Experiment: Test prediction by replacing batteries. Test prediction by replacing bulb. Test does not falsify hypothesis. Make additional predictions and test them.

1.9 Scientists form and test hypotheses and share their results An actual research project demonstrates the process of science.Scientists began with a set of observations and generalizations thatpoisonous animals are brightly colored andimposters resemble poisonous species but are actually harmless.They then tested the hypothesis that mimics benefit because predators confuse them with the harmful species. © 2012 Pearson Education, Inc.

1.9 Scientists form and test hypotheses and share their results The scientists conducted a controlled experiment, comparingan experimental group consisting of artificial king snakes anda control group consisting of artificial brown snakes.The groups differed only by one factor, the coloration of the artificial snakes.The data fit the key prediction of the mimicry hypothesis. © 2012 Pearson Education, Inc.

Coral snakes present Artificialking snakes Artificialbrown snakes 84% 0 20 40 60 80 100 Coral snakes absent 17% 16% Percent of total attacks on artificial snakes 83%

1.9 Scientists form and test hypotheses and share their results Science is a social activity with most scientists working in teams.Scientists share information in many ways.Science seeks natural causes for natural phenomena.The scope of science is limited to the study of structures and processes that we can directly observe and measure.Hypotheses about supernatural forces or explanations are outside the bounds of science, because they generate hypotheses that cannot be tested by science. © 2012 Pearson Education, Inc.

BIOLOGY AND EVERYDAY LIFE © 2012 Pearson Education, Inc.

1.10 CONNECTION: Biology, technology, and society are connected in important ways Many issues facing society are related to biology. Most involve our expanding technology.The basic goals of science and technology differ.The goal of science is to understand natural phenomena.The goal of technology is to apply scientific knowledge for some specific purpose. © 2012 Pearson Education, Inc.

1.10 CONNECTION: Biology, technology, and society are connected in important ways Although their goals differ, science and technology are interdependent.Technological advances stem from scientific research.Research benefits from new technologies. © 2012 Pearson Education, Inc.

1.11 EVOLUTION CONNECTION: Evolution is connected to our everyday lives Evolution is a core theme of biology.Evolutionary theory is useful inmedicine,agriculture,forensics, andconservation. © 2012 Pearson Education, Inc.

1.11 EVOLUTION CONNECTION: Evolution is connected to our everyday lives Human-caused environmental changes are powerful selective forces that affect the evolution of many species, includingantibiotic-resistant bacteria,pesticide-resistant pests,endangered species, andincreasing rates of extinction. © 2012 Pearson Education, Inc.

You should now be able to Describe seven properties common to all life.Describe the levels of biological organization from molecules to the biosphere, noting the interrelationships between levels.Define the concept of emergent properties and describe an example of it.Explain why cells are a special level in biological organization. Compare prokaryotic and eukaryotic cells.Compare the dynamics of nutrients and energy in an ecosystem. © 2012 Pearson Education, Inc.

You should now be able to Explain how DNA encodes a cell’s information.Compare the three domains of life.Describe the process and products of natural selection. Explain why individuals cannot evolve.Distinguish between quantitative and qualitative data.Compare the definitions and use of inductive and deductive reasoning in scientific investigations.Distinguish between a scientific theory and a hypothesis. © 2012 Pearson Education, Inc.

You should now be able to Distinguish between the scientific definition and common use of the word theory. Describe the structure of a controlled experiment and give an example.Compare the goals of science and technology. Explain why an understanding of science is essential to our lives.Explain how evolution impacts the lives of all humans. © 2012 Pearson Education, Inc.