Chapter 1: The Science of Biology PDF

Because learning changes everything.® Chapter 1 The Science of Biology Understanding Biology Fourth Edition Kenneth A. Mason, Tod Duncan Jonathan B. Losos © McGraw Hill LLC. All rights reserved. No r...

Because learning changes everything.® Chapter 1 The Science of Biology Understanding Biology Fourth Edition Kenneth A. Mason, Tod Duncan Jonathan B. Losos © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hill LLC.  Discovering the Nature of Life Darwin’s theory of evolution by natural selection is the core of the science of biology Biology is the study of living things The diversity of life is overwhelming Yet, all living things share common features © McGraw Hill, LLC 2  Biological Diversity Biological diversity is traditionally divided into three domains Organisms in a domain share similar characteristics Bacteria Archaea Eukarya The domain Eukarya can be divided into three multicellular kingdoms: Fungi, Plantae, and Animalia, and a diverse group of mostly unicellular organisms, the Protists. The Protists have no common ancestor unlike the eukaryotic kingdoms © McGraw Hill, LLC 3  Figures 1.1 and 1.2 (Archaea): Power and Syred/Science Source; (Bacteria): Alfred Pasieka/ Science Source (Protista): Dr. Stan Erlandsen and Dr. Dennis Feely/CDC; (Fungi): Russell Illig/Getty Images; (Plantae): Iconotec/Glow Images; (Animalia): Alan and Sandy Carey/ Getty Images The Archaea, Bacteria, Protists and three eukaryotic kingdoms are profoundly different from each other Access the text alternative for these images © McGraw Hill, LLC 4  Life Defies Simple Definition The properties of living organisms are also properties of many nonliving things All living things also share fundamental properties, passed down over millions of years from the first organisms to evolve on Earth 5 fundamental properties. © McGraw Hill, LLC 5  Fundaments Properties of Life Five fundamental characteristics 1. Cellular organization 2. Energy utilization 3. Homeostasis 4. Growth, development, & reproduction 5. Heredity © McGraw Hill, LLC 6  1 Cellular organization All living things are composed of one or more cells Cells carry out the basic activities of living Melba Photo Agency/Alamy Stock Photo Some cells are more complex than others © McGraw Hill, LLC 7  2 Energy utilization All living things use energy Moving, growing, and thinking require energy Energy is captured from sunlight by plants and algae through photosynthesis Other organisms extract energy from plants or from plant- eating animals © McGraw Hill, LLC 8  3 Homeostasis All living things maintain relatively constant internal conditions Organisms keep their interior conditions relatively constant even when the environment varies Ex. Your body maintaining 37C no matter how cold or hot it is outside. © McGraw Hill, LLC 9  4 Growth, development, & reproduction Bacteria increase in size and simply split in two Multicellular organisms grow by increasing the number of cells and develop by producing different kinds of cells Note: all living things can grow and reproduce, though all members of a species may not reproduce. © McGraw Hill, LLC 10  5 Heredity All organisms possess a genetic system based on the replication and duplication of DNA DNA transmits the characteristics of an organism from parent to offspring © McGraw Hill, LLC 11  Living systems show hierarchical organization 1 Cellular level Atoms Molecules Macromolecules Organelles Cells The cell is the basic unit of life © McGraw Hill, LLC 12  Figure 1.5 (1) (organelle): Keith R. Porter/Science Source Access the text alternative for these images © McGraw Hill, LLC 13  Living systems show hierarchical organization 2 Organismal level Tissues Organs Organ systems Organism © McGraw Hill, LLC 14  Figure 1.5 (2) (tissue): Ed Reschke/Getty Images; (organism): Russell Illig/Getty Images Access the text alternative for these images © McGraw Hill, LLC 15  Living systems show hierarchical organization 3 Populational level Population of specific species, community Ecosystem level Ecosystem, biosphere Each level has emergent properties © McGraw Hill, LLC 16  Figure 1.5 (3) (population): George Ostertaga/gefotostock/Alamy Stock Photo; (species top): USDA Natural Resources Conservation Service; (species bottom): U.S. Department of Agriculture (USDA); (community): Ryan McGinnis/Alamy Stock Photo; (ecosystem): Steven P. Lynch/McGraw Hill; (biosphere): Goddard Space Flight Center/NASA Access the text alternative for these images © McGraw Hill, LLC 17  The Nature of Science Science aims to understand the natural world through observation and reasoning Natural forces acting now have always acted The fundamental nature of the universe has not changed since its inception © McGraw Hill, LLC 18  The Scientific Process Descriptive science Observations lead to hypotheses Hypotheses are experimentally testable Much of science is purely descriptive Classifying all life on Earth; Sequencing of human genome Logical Reasoning Two types © McGraw Hill, LLC 19  Types of reasoning Deductive reasoning Applies general principles to predict specific results Deductive reasoning is used to infer the species of a specimen from its characteristics Inductive reasoning Uses specific observations to construct general scientific principles © McGraw Hill, LLC 20 © McGraw Hill, LLC 21  Hypothesis-driven science makes and tests predictions Observation Hypothesis formation Prediction Experimentation Conclusion © McGraw Hill, LLC 22  Figure 1.6 Access the text alternative for these images © McGraw Hill, LLC 23  A hypothesis is a possible explanation for an observation A hypothesis Must generate testable predictions Tested by experiments Hypotheses are either supported or rejected If rejected, hypotheses can be modified or written anew Supported hypotheses are subject to replication, additional testing, and being refined with new data © McGraw Hill, LLC 24  Experiment Tests the hypothesis Consists of an experimental treatment and a control group Experimental treatment, the variable of interest is altered to test a particular hypothesis Control group, the variable of interest is left unaltered Independent variable: what you manipulate in the experiment Dependent variable: what you observe or measure © McGraw Hill, LLC 25  Experiment to test spontaneous generation versus germ hypothesis Access the text alternative for these images © McGraw Hill, LLC 26  Scientific theories “Theory” is used in two ways by scientists: 1. Proposed explanation for a natural phenomenon; based on general principles – deductive 2. Body of interconnected concepts to explain facts; supported by scientific reasoning and experimental evidence – inductive Expresses ideas of which we are most certain © McGraw Hill, LLC 27  Philosophical approaches to science Reductionism To break a complex process down to its simpler parts Systems biology Examines the whole of a system as well as the workings of the parts © McGraw Hill, LLC 28  Models are used in science Models help us to organize thought Parts provided by reductionist approach Model shows how the parts fit together Suggest experiments to test the model © McGraw Hill, LLC 29  Science as a social construct Research results are published in scientific journals Experiments and conclusions are reviewed by other scientists Other scientists can use the publication to reproduce the experiment Challenges may exist with reproducibility of experiments Misuse of statistics, scientific fraud, and others © McGraw Hill, LLC 30  Example of scientific inquiry: Evolution Example of how a scientist develops a hypothesis and a theory gains acceptance Charles Darwin served as naturalist on mapping expedition around coastal South America 30 years of observation and study before publishing On the Origin of Species by Means of Natural Selection © McGraw Hill, LLC 31  Voyage of the HMS Beagle Huntington Library/Superstock Access the text alternative for these images © McGraw Hill, LLC 32  Darwin Darwin was not the first to propose evolution Living things have changed over time Darwin’s contribution was a mechanism Natural selection © McGraw Hill, LLC 33  Figure 1.10 On the Beagle, Darwin saw that characteristics of similar species varied from place to place Galápagos Finches 14 related species differ only slightly “Descent with modification” or evolution Access the text alternative for these images © McGraw Hill, LLC 34  Darwin studied Thomas Malthus’s An Essay on the Principle of Population Populations of plants and animals increase geometrically Humans can only increase their food supply arithmetically Populations of species remain constant because death limits population numbers Figure 1.11 Access the text alternative for these images © McGraw Hill, LLC 35  Selection Darwin saw that although every organism has the potential to produce more offspring, only a limited number do survive and reproduce themselves Those with advantageous traits are more likely to survive and reproduce Frequency of such traits increases in the population Nature of the population changes © McGraw Hill, LLC 36  Natural Selection Darwin proposed that a natural process could select for certain advantageous traits Years later, Darwin read Wallace’s hypothesis of evolution by means of natural selection The two men presented their ideas together, and Darwin published his manuscript © McGraw Hill, LLC 37  Evidence supporting Darwin’s theory has only grown Fossil record Transitional forms have been found at predicted positions in time Fossils show life on Earth back to about 3.5 billion years ago © McGraw Hill, LLC 38  Figure 1.12 Access the text alternative for these images © McGraw Hill, LLC 39  Comparative anatomy Vertebrate forelimbs all share the same basic array of bones Homologous – same evolutionary origin but now differ in structure and function Analogous – structures of different origin used for the same purpose (butterfly and bird wings) © McGraw Hill, LLC 40  Figure 1.13 Access the text alternative for these images © McGraw Hill, LLC 41  Figure 1.14 Molecular Evidence Compare genomes or proteins of different organisms Phylogenetic trees – based on tracing origin of particular nucleotide changes to reconstruct an evolutionary history Access the text alternative for these images © McGraw Hill, LLC 42  Five concepts unify biology 1. Life is subject to chemical and physical laws 2. Structure determines function 3. Living systems transform energy and matter 4. Livings systems depend on information transactions 5. Evolution explains the unity and diversity of life © McGraw Hill, LLC 43  Life is subject to chemical and physical laws Living systems operate according to chemical and physical principles Biological systems are the ultimate application of chemistry Examples Movement of water in plants Kidneys as an osmotic machine © McGraw Hill, LLC 44  Structure and function Study structure to learn function Know a function – look for that structure in other organisms Example Receptor on human cell for insulin known Find similar molecule in a worm Might conclude this molecule functions the same in the worm © McGraw Hill, LLC 45  Living systems transform energy and matter Constant supply of energy needed Self-organizing properties at different levels Emergent properties from collections of molecules, cells, and individuals Example: Self organization of the spindle apparatus Waheeb Heneen, the Swedish University of Agricultural Sciences © McGraw Hill, LLC 46  Living systems depend on information transactions Deoxyribonucleic acid (DNA) consists of sequence of nucleotides Genome – entire set of DNA instructions Continuity of life depends on faithful copying of DNA into daughter cells LAGUNA DESIGN/Science Photo Library/Alamy Stock Photo © McGraw Hill, LLC 47  Cells are information-processing systems Information in DNA used to direct synthesis of cellular components Control of gene expression leads to different cells/tissue types Cells process environmental information © McGraw Hill, LLC 48  Evolution explains the unity and diversity of life All organisms today descended from a simple creature 3.5 BYA Some characteristics preserved – use of DNA Conserved characteristics reflect that they have a fundamental role © McGraw Hill, LLC 49  Because learning changes everything. ® www.mheducation.com © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hill LLC.