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ZOOLOGY. BIO 141. Dr. Sumithran. http://people.eku.edu/sumithrans/Zoo/Home.html. Introduction. What is life?. Introduction. Difficult to define Therefore discuss properties of living systems. Properties of Living Systems. 1) Chemical Uniqueness Made up of large molecules MACROMOLECULES
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ZOOLOGY BIO 141 Dr. Sumithran
Introduction • What is life?
Introduction • Difficult to define • Therefore discuss properties of living systems
Properties of Living Systems • 1) Chemical Uniqueness • Made up of large molecules • MACROMOLECULES • Four categories • Nucleic Acids • Proteins • Carbohydrates • Lipids
Properties of Living Systems • 2) Complexity and Hierarchical Organization • One level builds on previous level • Macromolecules • Cells • Tissue • Organs • Organ system etc • Emergent Characteristics – • Unique characteristics that appear at a given level of organization
Properties of Living Systems • 3) Reproduction • Replacement of individuals in a population • Types of Reproduction • Asexual • Sexual
Properties of Living Systems • 4) Possession of a Genetic Program • Faithful transmission of traits – Heredity • Information contained in Genes • Specifically encoded in the DNA
Properties of Living Systems • 5) Metabolism • Complex chemical processes that go on in cells – provide energy • Two processes • Anabolism – Building up reactions • Catabolism – Breaking down reactions
Properties of Living Systems • 6) Growth / Development • Changes that take place during the life of an organism • Metamorphosis – The transformation that take place in post-embryonic stages
Properties of Living Systems • 7) Environmental Interaction • Ecology – Study of interactions between organisms and their environment • Organisms responding to stimuli from environment • IRRITABILITY
Charles Darwin • Galapagos Islands • 1859 – Published “The Origin of Species” • Major obstacle – Heredity not understood • 5 major theories
DARWIN’S THEORY OF EVOLUTION • 1) Perpetual Change • Living world is neither constant nor cyclic instead is constantly changing • Fossil Evidence • 99% of species that once lived on the planet now extinct
DARWIN’S THEORY OF EVOLUTION • 2) Common Descent • All forms of life descended from a common ancestor through branching lineages • PHYLOGENY • DNA studies – Provide evidence
DARWIN’S THEORY OF EVOLUTION • 3) Multiplication of Species • new species are produced by the splitting and transformation of older ones • Process known as – Speciation
DARWIN’S THEORY OF EVOLUTION • 4) Gradualism • Large differences that characterize different species, originate through the accumulation of small changes over a period of time • Did not take place overnight – but over geological time
DARWIN’S THEORY OF EVOLUTION • 5) Natural Selection • Explains why organisms are constructed the way they are • To meet the demands of their environment
CLASSIFICATION • Developed by Linnaeus
Categories of Animal Classification • Kingdom - Animalia • Phylum - Chordata • Class - Mammalia • Order - Primates • Family - Hominidae • Genus - Homo • Species - sapiens
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