Exploring Life: Biology Concepts PDF

1 _ Exploring Life Themes in the Study of Biology Evolution, the Core Theme of Biology The Process of Science © 2016 Pearson Education, Ltd.  Key Concepts...

1 _ Exploring Life Themes in the Study of Biology Evolution, the Core Theme of Biology The Process of Science © 2016 Pearson Education, Ltd.  Key Concepts What is life? How do you de2ne life? Hierarchy of Life What is cell? Why is a cell called the func7onal unit of life? The 2 forms of cells Ecosystem – living & non-living factors Dynamics in an ecosystem The concept of evolu7on – Charles Darwin, unity and diversity, descent with modi2ca7on, natural selec7on What is science? Discovery versus hypothesis-based science Quan7ta7ve vs qualita7ve data Induc7ve vs deduc7ve reasoning The process of science Theory vs hypothesis © 2016 Pearson Education, Ltd.  All forms of life share common properties Biology is the scientific study of life Life properties are the characteristics shared by all living things 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 5. Regulation—an ability to control an organism’s internal environment within limits that sustain life © 2016 Pearson Education, Ltd.  6. Response to the environment—an ability to respond to environmental stimuli 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 (1) Order (2) Reproduction (3) Growth and (4) Energy processing development (5) Regulation (6) Response to the (7) Evolutionary adaptation © 2016 Pearson Education, Ltd. environment In life’s hierarchy of organization, new properties emerge at each level Biological organization unfolds as follows (from the complex to simple): 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 Organism—an individual living thing © 2016 Pearson Education, Ltd.  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 Organelle—a membrane-enclosed structure that performs a specific function within a cell Molecule—a cluster of small chemical units called atoms held together by chemical bonds Emergent properties are new properties that arise in each step upward in the hierarchy of life from the arrangement and interactions among component parts © 2016 Pearson Education, Ltd. Figure 1.2-0 Biosphere Ecosystem Florida Florida Everglades Community All organisms in this wetland ecosystem Population All alligators living in the wetlands Organism an American alligator © 2016 Pearson Education, Ltd. Figure 1.2-1 Organism an American alligator Spinal Organ system Nerve Nervous system cord Brain Organ Brain Tissue Nervous tissue Atom Cell Nucleus Nerve cell Organelle Molecule Nucleus DNA © 2016 Pearson Education, Ltd. Cells are the structural and functional units of life Cells are the level at which the properties of life emerge – basic unit of life A cell can: o regulate its internal environment o take in and use energy o respond to its environment o develop and maintain its complex organization o give rise to new cells All cells: o are enclosed by a membrane that regulates the passage of materials between the cell and its surroundings o use DNA as their genetic information © 2016 Pearson Education, Ltd.  Two basic forms of cells: There are two basic forms of cells 1. Prokaryotic cells were the first to evolve are found in bacteria and archaea are simpler are usually smaller than eukaryotic cells 2. Eukaryotic cells are found in plants, animals, fungi, and protists are subdivided by membranes into various functional compartments, or organelles, including a nucleus that houses the DNA © 2016 Pearson Education, Ltd. Figure 1.3 Prokaryotic cell DNA Eukaryotic cell (no nucleus) Membrane Organelles Nucleus (membrane- enclosed) DNA (throughout nucleus) © 2016 Pearson Education, Ltd.  Organisms interact with their environment, exchanging matter and energy Living organisms interact with their environments, which include o other organisms o physical factors In most ecosystems, o plants are the “producers” that provide the food o animals are “consumers” that eat plants & other animals o “decomposers” act as recyclers, changing complex matter into simpler chemicals that plants can absorb and use © 2016 Pearson Education, Ltd.  Dynamics of ecosystems 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 2. the one-way flow of energy through an ecosystem, entering as sunlight and exiting as heat © 2016 Pearson Education, Ltd. Figure 1.4 ENERGY FLOW Sun Inflow of Outflow of light energy heat Consumers (animals) Producers (plants) Chemical energy Leaves take up in food Decomposers such CO2 from air; roots as worms, fungi, absorb H2O and and bacteria return minerals from soil chemicals to soil © 2016 Pearson Education, Ltd.