Biology: Exploring Life Lecture Notes PDF

Chapter 1 Biology: Exploring Life werPoint Lectures mpbell Biology: Concepts & Connections, Eighth Edition CE TAYLOR SIMON DICKEY HOGAN Lecture by Edward J. Zalisko © 2015 Pearson  Biology: Exploring Life...

Chapter 1 Biology: Exploring Life werPoint Lectures mpbell Biology: Concepts & Connections, Eighth Edition CE TAYLOR SIMON DICKEY HOGAN Lecture by Edward J. Zalisko © 2015 Pearson  Biology: Exploring Life 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 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, © 2012 Pearson Education, Inc. 1.1 All forms of life share common properties 5. Response to the environment—an ability to respond to environmental stimuli, 6. Regulation—an ability to control an organism’s internal environment within limits that sustain life, 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. © 2012 Pearson Education, Inc. Figure 1.1-0 (1) Order (2) Reproduction (3) Growth and (4) Energy development processing (5) Regulation (6) Response to the (7) Evolutionary adaptation environment © 2015 Pearson Education, Inc. Figure 1.1-0 (1) Order (2) Reproduction (3) Growth and (4) Energy development processing (5) Regulation (6) Response to the (7) Evolutionary adaptation environment © 2015 Pearson Education, Inc. A cell phone is not alive. 1.List three characteristics of life that the phone does not perform. A cell phone is not alive. 1.List three characteristics of life that the phone does not perform 2. What properties of life does it exhibit ? 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, FOR EXAMPLE: CIRCULATORY SYSTEM: HEART, BLOOD VESSELS – 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, and – Molecule—a cluster of small chemical units called atoms held together by chemical bonds. © 2012 Pearson Education, Inc. Figure 1.2-1 Biosphere Ecosystem Florida Florida Everglades Community All organisms in this wetland ecosystem Population All alligators living in the wetlands Organism an American alligator © 2015 Pearson Education, Inc. Figure 1.2-2 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 © 2015 Pearson Education, Inc. 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. © 2012 Pearson Education, Inc. 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. © 2012 Pearson Education, Inc. 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. © 2012 Pearson Education, Inc. 1.3 Cells are the structural and functional units of life  There are two basic types of cells. 1. Prokaryotic cells – were the first to evolve, – are simpler, and – are usually smaller than eukaryotic cells. 2. Eukaryotic cells – contain membrane-enclosed organelles, including a nucleus containing DNA, and – are found in plants, animals, and fungi. (AND MANY PROTISTS.) © 2012 Pearson Education, Inc. Figure 1.3 DNA Prokaryotic Eukaryotic cell (no nucleus) cell Membrane Organelles Nucleus (membrane- enclosed) DNA (throughout nucleus) 1.3 Cells are the structural and functional units of life  Cells illustrate a theme in biology: the correlation of structure and function.  Structure is related to function at all levels of biological organization. © 2012 Pearson Education, Inc. 1.4 Living 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 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: 1. The recycling of chemical nutrients from the atmosphere and soil through producers, consumers, and decomposers back to the environment. 2. 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. Figure 1.4-0 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 © 2015 Pearson Education, Inc. Figure 1.4_1 Ecosystem O2 O2 Sunlight Heat Producers Consumers (such as (such as plants) animals) Chemical energy (food) CO2 CO2 Water and minerals Cycling of Decomposers taken up by tree roots chemical nutrients (in soil)  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.  Genes – are the unit of inheritance that transmits information from parents to offspring, – are grouped into very long DNA molecules called chromosomes, and – control 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 C G C G A T A C G T A T A T C G G C 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. 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. © 2012 Pearson Education, Inc. Figure 1.6 Domain Bacteria Domain Eukarya Bacteria Domain Archaea Protists Kingdom Plantae (multiple kingdoms) Archaea Kingdom Fungi Kingdom Animalia Figure 1.6_1 Domain Bacteria Bacteria Figure 1.6_2 Domain Archaea Archaea Figure 1.6_3 Domain Eukarya Protists Kingdom Plantae (multiple kingdoms) Kingdom Fungi Kingdom Animalia 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 (ABOUT 4.5 BILLION YEARS.) – inhabited by an evolving cast of life forms.  Evolution accounts for life’s dual nature of – kinship and – diversity. © 2012 Pearson Education, Inc. 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. Figure 1.7C 1 Population with varied inherited traits 2 Elimination of individuals with certain traits 3 Reproduction of survivors 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, and – the result will be evolutionary adaptation, the accumulation of favorable traits in a population over time. © 2012 Pearson Education, Inc. Figure 1.7D 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.  Scientists – use inductive reasoning to draw general conclusions from many observations and – deductive 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 is – much broader in scope than a hypothesis, – usually general enough to generate many new, specific hypotheses, which can then be tested, and – supported 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 be – testable and – falsifiable. – In this example, two hypotheses are tested. © 2012 Pearson Education, Inc. Copyright © 2010 Pearson Education, Inc.  This is what they really looked like Copyright © 2010 Pearson Education, Inc. Copyright © 2010 Pearson Education, Inc. Copyright © 2010 Pearson Education, Inc.  Turn off the lights in the room and use a small flashlight around the bowl. You can move the light around to get your sea monkeys to dance, somersault or do anything else you like. Copyright © 2010 Pearson Education, Inc.   Process, using the scientific method:  Observing: Sea Monkeys follow a flashlight when it is turned on.  Proposing questions: Do Sea Monkeys move toward heat or light?  Forming a testable, falsifiable hypothesis.  Testing, then observe movement. More testing, then observe movement  Discard those ideas that fail Copyright © 2010 Pearson Education, Inc. Figure 1.9A_s1 Observation Question Hypothesis 1: Hypothesis 2: move towards heat Move towards light Figure 1.9A_s2 Observation Question Hypothesis 1: Hypothesis 2: Move towards heat Move towards light source Prediction: Prediction: If a source of heat is If light source is added.. applied… Experiment: Experiment:. Figure 1.9A_s3 Observation Question Hypothesis 1: Hypothesis 2: Prediction: Prediction: Experiment: Experiment: Test prediction by Test prediction by Test falsifies Test does not hypothesis. Revise falsify hypothesis. hypothesis or Make additional pose new one. predictions and test them.  Hypothesis Testing The Scientific Method  Variables: factors that can change in value under different conditions Controlled Variables: factors that are kept constant Independent variables can be manipulated by the scientist, also known as experimental variables. Dependent variables cannot be changed by the scientist (can be measured by the scientist.) Copyright © 2010 Pearson Education, Inc.  Hypothesis Testing  Control: a subject which is not exposed to the experimental treatment Differences can be attributed to the experimental treatment (independent variable). Copyright © 2010 Pearson Education, Inc.   1. If skin cancer is related to ultraviolet light, then people with a high exposure to UV light will have a higher frequency of skin cancer. What will you do to test this proposal? What will you vary or change? (Independent variable)  What will you measure? (Dependent variable)  2. If leaf color change is related to temperature, then exposing plants to low temperatures will result in changes in leaf color.  Independent variable – Dependent variable -  3. If the speed of plant germination is related to the hardness of the hull of its seed, then softening the seed with water or a weakly acidic solution prior to planting will hasten germination. Blah, Blah, Blah…  Independent variable –  Dependent variable -  4. If photosynthesis is related to light energy, then the portions of a leaf shaded from light will test negative for starch, since starch is a product of photosynthesis.  Independent variable –  Dependent variable -   5. If animal metabolism is related to temperature, then increasing resting room temperature will increase animal metabolism (as measured by carbon dioxide gas production which is one of the waste products of animal metabolism).  Independent variable –   Dependent variable -    6. If root growth is related to gravity, then roots will always turn toward the earth regardless of a seed's orientation.  Independent variable –   Dependent variable - Copyright © 2010 Pearson Education, Inc.  Your Scientific method 1. What was your observation? 2. What was your hypothesis? A proposed explanation for your observations. 3. What was the independent variable? (What factor was changed by the scientist (you?) 4. What was the dependent variable? (What factors couldn’t be changed by the scientists? Or in other words what was measured by the scientist (you)?) Aka, you measured the results. 5. Did you have a control group? (Did you have a group that did not receive the experimental treatment?) Copyright © 2010 Pearson Education, Inc. 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 that – poisonous animals are brightly colored and – imposters 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, comparing – an experimental group consisting of artificial king snakes and – a 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. Figure 1.9B Figure 1.9C Figure 1.9D Figure 1.9D_1 Figure 1.9D_2 Figure 1.9E 100 Artificial 83% 84% king snakes Percent of total attacks 80 on artificial snakes Artificial brown snakes 60 40 20 17% 16% 0 Coral snakes Coral snakes absent present