Chapter 1 Biology: Exploring Life

Transcription

1 Chapter 1 Biology: Exploring Life PowerPoint Lectures Campbell Biology: Concepts & Connections, Eighth Edition REECE TAYLOR SIMON DICKEY HOGAN Lecture by Edward J. Zalisko

2 Introduction Snowy owls exhibit adaptations for life in their frozen, barren habit, including feathers that provide insulation in subzero weather and keen vision and acute hearing that help owls locate prey. Snowy owls are the result of evolution, the process that has transformed life from its earliest beginnings.

3 Figure 1.0-1

4 THEMES IN THE STUDY OF BIOLOGY THEMES IN THE STUDY OF BIOLOGY

5 1.1 All forms of life share common properties Biology is the scientific study of life. Properties of life include 1. Order the highly ordered structure that typifies life, 2. Reproduction the ability of organisms to reproduce their own kind, 3. Growth and development consistent growth and development controlled by inherited DNA, 4. Energy processing the use of chemical energy to power an organism s activities and chemical reactions,

6 1.1 All forms of life share common properties 5. Regulation an ability to control an organism s internal environment within limits that sustain life, 6. Response to the environment an ability to respond to environmental stimuli, and 7. Evolutionary 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.

7 Video: Sea Horses

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

9 Figure Order

10 Figure Reproduction

11 Figure Growth and development

12 Figure Energy processing

13 Figure Regulation

14 Figure Response to the environment

15 Figure Evolutionary adaptation

16 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,

17 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, Tissue a group of similar cells that perform a specific function, Cell the fundamental unit of life,

18 1.2 In life s hierarchy of organization, new properties emerge at each level Organelle a membrane-enclosed structure that performs a specific function within a cell, and Molecule a cluster of small chemical units called atoms held together by chemical bonds.

19 Figure Biosphere Florida Ecosystem Florida Everglades Community All organisms in this wetland ecosystem Population All alligators living in the wetlands Organism an American alligator Nerve Spinal cord Organ system Nervous system Brain Organ Brain Tissue Nervous tissue Cell Nerve cell Nucleus Atom Organelle Nucleus Molecule DNA

20 Figure Biosphere Florida Ecosystem Florida Everglades Community All organisms in this wetland ecosystem Population All alligators living in the wetlands Organism an American alligator

21 Figure Organism an American alligator Nerve Spinal cord Organ system Nervous system Brain Organ Brain Tissue Nervous tissue Atom Cell Nerve cell Nucleus Organelle Nucleus Molecule DNA

22 Figure Biosphere

23 Figure Community: All the organisms in this wetland ecosystem

24 Figure Population: All alligators living in the wetlands

25 Figure Atom Molecule: DNA

26 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.

27 1.3 Cells are the structural and functional units of life Cells are the level at which the properties of life emerge. A cell can regulate its internal environment, take in and use energy, respond to its environment, develop and maintain its complex organization, and give rise to new cells.

28 1.3 Cells are the structural and functional units of life All cells are enclosed by a membrane that regulates the passage of materials between the cell and its surroundings and use DNA as their genetic information.

29 1.3 Cells are the structural and functional units of life There are two basic forms of cells. 1. Prokaryotic cells were the first to evolve, are simpler, and are usually smaller than eukaryotic cells. 2. Eukaryotic cells are found in plants, animals, fungi, and protists and are subdivided by membranes into various functional compartments, or organelles, including a nucleus that houses the DNA.

30 Figure 1.3 Eukaryotic cell DNA (no nucleus) Membrane Prokaryotic cell Organelles Nucleus (membrane- enclosed) DNA (throughout nucleus)

31 1.3 Cells are the structural and functional units of life Systems biology is the study of a biological system and the modeling of its dynamic behavior, ranging from the functioning of the biosphere to the complex molecular machinery of an organelle.

32 1.3 Cells are the structural and functional units of life Cells illustrate another theme in biology: the correlation of structure and function. Structure is related to function at all levels of biological organization.

33 1.4 Organisms interact with their environment, exchanging matter and energy Living organisms interact with their environments, which include other organisms and physical factors. In most ecosystems, plants are the producers that provide the food, consumers eat plants and other animals, and decomposers act as recyclers, changing complex matter into simpler chemicals that plants can absorb and use.

34 1.4 Organisms interact with their environment, exchanging matter and energy The dynamics of ecosystems include two major processes: 1. the recycling of chemical nutrients from the atmosphere and soil through producers, consumers, and decomposers back to the air and soil and 2. the one-way flow of energy through an ecosystem, entering as sunlight and exiting as heat.

35 Figure ENERGY FLOW Sun Inflow of light energy Outflow of heat Producers (plants) Consumers (animals) Leaves take up CO 2 from air; roots absorb H 2 O and minerals from soil Chemical energy in food Decomposers such as worms, fungi, and bacteria return chemicals to soil

36 Figure ENERGY FLOW Sun Inflow of light energy Outflow of heat Producers (plants) Consumers (animals) Leaves take up CO 2 from air; roots absorb H 2 O and minerals from soil Chemical energy in food Decomposers such as worms, fungi, and bacteria return chemicals to soil

37 Figure 1.4-2

38 EVOLUTION, THE CORE THEME OF BIOLOGY

39 1.5 The unity of life is based on DNA and a common genetic code All cells have DNA, the chemical substance of genes. Genes are the unit of inheritance that transmit information from parents to offspring, are grouped into very long DNA molecules called chromosomes, and control the activities of a cell.

40 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 kinds of 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.

41 Figure Nucleus DNA Cell C G C G G C G C T A A T C G A T A C G T A T C G G C C A T G A T T A

42 Figure Nucleus DNA Cell C G C G G C G C T A A T

43 Figure C G A T A C G T A T C G G C C A T G A T T A

44 1.5 The unity of life is based on DNA and a common genetic code The entire library of genetic instructions that an organism inherits is called its genome. In recent years, scientists have determined the entire sequence of nucleotides in the human genome.

45 1.6 The diversity of life can be arranged into three domains We can think of biology s enormous scope as having two dimensions. 1. The vertical dimension is the size scale that stretches from molecules to the biosphere. 2. The horizontal dimension spans across the great diversity of organisms existing now and over the long history of life on Earth.

46 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 range from 10 million to over 100 million. Taxonomy is the branch of biology that names species and classifies species into a hierarchy of broader groups: genus, family, order, class, phylum, and kingdom.

47 1.6 The diversity of life can be arranged into three domains The diversity of life can be arranged into three higher levels called domains. 1. Bacteria are the most diverse and widespread prokaryotes. 2. Archaea are prokaryotes that often live in Earth s extreme environments. 3. Eukarya have eukaryotic cells and include single-celled protists and multicellular fungi, animals, and plants.

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

49 Figure Domain Bacteria Bacteria

50 Figure Domain Archaea Archaea

51 Figure Domain Eukarya Protists (multiple kingdoms) Kingdom Plantae Kingdom Fungi Kingdom Animalia

52 Figure Protists (multiple kingdoms)

53 Figure Kingdom Plantae

54 Figure Kingdom Fungi

55 Figure Kingdom Animalia

56 1.7 Evolution explains the unity and diversity of life Evolution can be defined as the process of change that has transformed life on Earth from its earliest beginnings to the diversity of organisms living today. The fossil record documents that life has been evolving on Earth for billions of years and the pattern of ancestry.

57 Figure 1.7a

58 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. Species living today descended from ancestral species in what Darwin called descent with modification. 2. Natural selection is a mechanism for evolution.

59 Video: Galápagos Island Overview

60 Video: Galápagos Marine Iguana

61 Video: Galápagos Sea Lion

62 Video: Galápagos Tortoise

63 Figure 1.7b

64 Figure 1.7c-0

65 Figure 1.7c-1

66 Figure 1.7c-2

67 Figure 1.7c-3

68 1.7 Evolution explains the unity and diversity of life Natural selection was inferred by connecting two observations. 1. Individual variation: Individuals in a population vary in their traits, many of which are passed on from parents to offspring. 2. Overproduction of offspring: A population can produce far more offspring than the environment can support.

69 Video: Blue-footed Boobies Courtship Ritual

70 Video: Albatross Courtship Ritual

71 Video: Soaring Hawk

72 1.7 Evolution explains the unity and diversity of life From these observations, Darwin drew two inferences. 1. Unequal reproductive success: Individuals with heritable traits best suited to the environment are more likely to survive and reproduce than less well-suited individuals. 2. Accumulation of favorable traits over time: As a result of this unequal reproductive success over many generations, an increasing proportion of individuals in a population will have the advantageous traits.

73 Figure 1.7d-1 1 Population with varied inherited traits.

74 Figure 1.7d-2 1 Population with varied inherited traits. 2 Elimination of individuals with certain traits and reproduction of survivors.

75 Figure 1.7d-3 1 Population with varied inherited traits. 2 Elimination of individuals with certain traits and reproduction of survivors. 3 Increasing frequency of traits that enhance survival and reproductive success.

76 1.7 Evolution explains the unity and diversity of life Darwin realized that numerous small changes in populations as a result of natural selection could eventually lead to major alterations of species. The fossil record provides evidence of such diversification of species from ancestral species.

77 Figure 1.7e-0 Deinotherium Mammut Platybelodon Stegodon Mammuthus Elephas maximus (Asia) Loxodonta africana (Africa) Millions of years ago Years ago Loxodonta cyclotis (Africa)

78 Figure 1.7e-1 Deinotherium Mammut Platybelodon Stegodon Millions of years ago Years ago

79 Figure 1.7e-2 Mammuthus Elephas maximus (Asia) Loxodonta africana (Africa) Loxodonta cyclotis (Africa) Millions of years ago Years ago

80 THE PROCESS OF SCIENCE

81 1.8 In studying nature, scientists make observations and form and test hypotheses Science is a way of knowing that stems from our curiosity about ourselves and the world around us. Science is based upon inquiry, the search for information and explanations of natural phenomena. Scientists typically make observations, form hypotheses, proposed explanations for a set of observations, and test them.

82 1.8 In studying nature, scientists make observations and form and test hypotheses Two types of data are frequently collected in scientific investigations. 1. Qualitative data is descriptive. 2. Quantitative data includes numerical measurements.

83 1.8 In studying nature, scientists make observations and form and test hypotheses Scientists use two types of reasoning. 1. Inductive reasoning makes generalizations based on collecting and analyzing a large number of specific observations. 2. Deductive reasoning flows from general premises to predicted and specific results.

84 1.8 In studying nature, scientists make observations and form and test hypotheses 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? Two reasonable hypotheses are that 1. the batteries are dead or 2. the bulb is burned out.

85 Figure Observation: Flashlight doesn t work. Question: Why doesn t the flashlight work? Hypothesis #1: Batteries are dead. Hypothesis #2: Bulb is burned out.

86 Figure Observation: Flashlight doesn t work. Question: Why doesn t the flashlight work? Hypothesis #1: Batteries are dead. Hypothesis #2: Bulb is burned out. Prediction: Replacing batteries will fix problem. Prediction: Replacing bulb will fix problem. Test of prediction: Replace batteries. Test of prediction: Replace bulb.

87 Figure Observation: Flashlight doesn t work. Question: Why doesn t the flashlight work? Hypothesis #1: Batteries are dead. Hypothesis #2: Bulb is burned out. Prediction: Replacing batteries will fix problem. Prediction: Replacing bulb will fix problem. Test of prediction: Replace batteries. Test of prediction: Replace bulb. Results: Flashlight doesn t work. Hypothesis is contradicted. Results: Flashlight works. Hypothesis is supported.

88 1.8 In studying nature, scientists make observations and form and test hypotheses A scientific theory is much broader in scope than a hypothesis and supported by a large and usually growing body of evidence. Science is a social activity in which scientists work in teams, share information through peer-reviewed publications, meetings, and personal communication, and build on and confirm each other s work.

89 1.9 SCIENTIFIC THINKING: Hypotheses can be tested using controlled field studies Scientists conducted a controlled experiment to test the hypothesis that color patterns have evolved as adaptations that protect animals from predation. The experiment compared an experimental group consisting of noncamouflaged mice models and a control group consisting of camouflaged models that matched the mice native to each area. The groups differed by only one factor, the coloration of the mouse models.

90 Figure Beach population Inland population

91 Figure Beach population

92 Figure Inland population

93 1.9 SCIENTIFIC THINKING: Hypotheses can be tested using controlled field studies As presented in Table 1.9, the noncamouflaged models had a much higher percentage of attacks in the beach and inland habitats and these data fit the key prediction of the camouflage hypothesis.

94 Table 1.9

95 BIOLOGY AND EVERYDAY LIFE

96 1.10 EVOLUTION CONNECTION: Evolution is connected to our everyday lives Evolution is a core theme of biology. Humans selectively breed plants and animals in the process of artificial selection to produce move productive crops, better livestock, and a great variety of pets that bear little resemblance to their wild ancestors.

97 1.10 EVOLUTION CONNECTION: Evolution is connected to our everyday lives Humans also unintentionally cause the evolution of antibiotic-resistant bacteria, the evolution of pesticide-resistant pests, and the loss of species through habitat loss and global climate change.

98 Figure 1.10

99 1.11 CONNECTION: Biology, technology, and society are connected in important ways Many issues facing society are related to biology and often 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.

100 1.11 CONNECTION: Biology, technology, and society are connected in important ways Although their goals differ, science and technology are interdependent. Research benefits from new technologies. Technological advances stem from scientific research. Technologies of DNA manipulation are the results of scientific discovery of the structure of DNA.

101 You should now be able to 1. Describe seven properties common to all life. 2. Describe the levels of biological organization from molecules to the biosphere, noting the interrelationships between levels. 3. Define the concept of emergent properties and describe an example of it. 4. Explain why cells are a special level in biological organization. Compare prokaryotic and eukaryotic cells. 5. Compare the dynamics of nutrients and energy in an ecosystem.

102 You should now be able to 6. Explain how DNA encodes a cell s information. 7. Compare the three domains of life. 8. Describe the process and products of natural selection. 9. Distinguish between quantitative and qualitative data. 10. Compare the definitions and use of inductive and deductive reasoning in scientific investigations. 11. Distinguish between a scientific theory and a hypothesis.

103 You should now be able to 12. Describe the structure of a controlled experiment and give an example. 13. Explain how evolution impacts the lives of all humans. 14. Compare the goals of science and technology. Explain why an understanding of science is essential to our lives.

104 Figure 1.UN01 ENERGY FLOW Light Heat Producers Consumer Chemical energy

105 Figure 1.UN02

106 Figure 1.UN03 Observations Heritable variations Overproduction of offspring Inferences Natural selection: Unequal reproductive success leads to evolution of adaptations in populations.

107 Figure 1.UN04 Biology is the study of (a) has changed through the process of (c) (b) mechanism is depends on accounts for DNA (genetic code) accounts for leads to codes for is evidence of diversity of life (d) seen in seen in variations in seen in (e) cells as basic units of life common properties of living organisms

108 Figure 1.UN05 Average time to complete maze (min) No reward Food reward Day