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6 Unifying Themes of Biology:
Cell Structure and Function Stability and Homeostasis Reproduction and Inheritance Evolution Interdependence of Organisms Matter, Energy and Organization
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1. Cellular Structure and Function:
Cells: The smallest unit capable of life functions Unicellular: Single cell that performs all of life's functions Multicellular: More than one cell with division of labor Humans bodies are made of more than 50 trillion cells
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What is a Cell? Small, highly organized and contains the materials to carry out life's processes. 2 WAYS ALL CELLS ARE SIMILAR: Surrounded with a membrane Have genetic information Differentiation: Process by which cells in a multicellular organism become different. (DOES NOT HAPPEN IN UNICELLULAR ORGANISMS)
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2. Homeostasis The maintenance of a stable internal environment in spite of the external environment Required for survival The elephant's ears are important for cooling. Elephants do not have sweat glands, so they an alternative way to remove excess heat from their bodies. The ears are very thin, and have many blood vessels. As the elephant moves its ears, the surrounding air absorbs some of the heat, cooling the blood by as much as ten degrees Fahrenheit. By flapping their ears, they keep a stream of cooler air moving over their ears, carrying away more heat.
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3. Reproduction and Inheritance:
Asexual Reproduction -Doesn’t involve the union of GAMETES (sex cells) Example: Bacteria Sexual Reproduction -Involves the union of sex cells Sperm + Egg = Zygote Embryo
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HEREDITY DNA -Genetic information is found on Double helix nucleic acid Gene - Short segment of DNA that carries the code for various proteins and other substances Inheritance -The acquisition of traits by offspring
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4. EVOLUTION: The theory that organisms evolve or change over time.
Natural Selection: -survival of the fittest (*) Adaptation: -A trait that increases an organisms chance of surviving in it’s environment.
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5. Interdependence ECOSYSTEMS
ECOLOGY: The study of the relationship between organisms and their environment ECOSYSTEMS The biotic and abiotic characteristics interacting
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6. Matter, Energy and Organization
Autotroph: -An organism that is able to produce it’s own food Heterotroph: -An organism that cannot make it’s own food
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What do I know?
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CELLS: Cells are the basic structure of life Organisms may be: UNICELLULAR: Single cell performs all of life’s functions MULTICELLULAR: Division of labor; Cells perform specific functions to support the organism
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2. Organization Cells are built from organized structures: ORGANELLES
Multicellular organism show COMPLEXITY Cell – tissue – organ – organ system - organism
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3) Use energy: All organisms use energy in METABOLISM
The sum of all the chemical processes in an organism Use energy to: Maintain organization Grow Reproduce
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4) Respond to the environment:
RESPONSE – A reaction to a stimulus BEHAVIOR – A complex set of responses to a stimulus
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5. Reproduce: 1. ASEXUAL 2. SEXUAL 6. Adapt: ADAPTATIONS are those traits that give an organism a better chance of survival in it’s environment.
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7) Growth: CELL DIVISION MITOSIS MEIOSIS CELL ENLARGEMENT
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8) Have a LIFE CYCLE
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III. THE SCIENTIFIC METHOD:
A series of steps that are followed to answer questions and/or solve problems.
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A.Observation and data collection:
The use of one or more senses to perceive objects or events
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DATA COLLECTION: SAMPLING:
Gathering and Recording of specific information based on observations *Ask a question or Recognize a problem SAMPLING: Collecting a small representative portion of the population
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Section 1.3 Summary – pages 19-23
Kinds of Information Scientific information can usually be classified into one of two main types, quantitative or qualitative. Section 1.3 Summary – pages 19-23
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Section 1.3 Summary – pages 19-23
Quantitative information Biologists sometimes conduct controlled experiments that result in counts or measurements—that is, numerical data. These kinds of experiments occur in quantitative research. The data are analyzed by comparing numerical values. Section 1.3 Summary – pages 19-23
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Section 1.3 Summary – pages 19-23
Quantitative information Paramecium Survival Rates Quantitative data may be used to make a graph or table. Number of paramecia surviving Temperature Section 1.3 Summary – pages 19-23
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Section 1.3 Summary – pages 19-23
Quantitative information Graphs and tables communicate large amounts of data in a form that is easy to understand. Paramecium Survival Rates Number of paramecia surviving Temperature Section 1.3 Summary – pages 19-23
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Section 1.3 Summary – pages 19-23
Qualitative information Observational data—that is, written descriptions of what scientists observe—are often just as important in the solution of a scientific problem as numerical data. When biologists use purely observational data, they are using qualitative information. Section 1.3 Summary – pages 19-23
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Data Organization: Recording data in a meaningful format that is easier to understand and analyze Charts Graphs Tables Maps
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Establishing a Hypothesis:
A proposed explanation of a phenomenon Must be testable Typically based on previous observations that are not satisfactorily explained by current theory
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The process of testing a hypothesis in a repeatable fashion
C. Experimenting: The process of testing a hypothesis in a repeatable fashion CONTROLLED EXPERIMENTS: Experiments that allow for comparison of a control and experimental group EXPERIMENTAL - Group your testing CONTROL - Group your comparing the experimental group with
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Controlled Experiments
Independent Variable: Factor that being tested or manipulated The Independent variable is not included in the control DEPENDENT VARIABLE: One main factor of the control and experimental group being measured “responding variable”
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Controlled Experiment
experimental control
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How will grass grow in Pittsburgh???
KEEP THE ROOTS WARM
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D. Analyzing Data: Determining whether data are reliable and whether they support or refute a given prediction or hypothesis using statistics, interpreting graphs, determining relationships between variables, comparing the data of other studies, determining sources of experimental error
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Inferring: Inference:
A conclusion based on facts or premises rather than a direct observation. Example: You see smoke, so you infer that a fire is occurring. CONCLUSION: A final determination of the problem based on the results of all findings.
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Question 1 What is the difference between a hypothesis and an observation? Section 2 Check
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A hypothesis is an explanation for a question or problem and can be formally tested. An observation is something that has been noticed, often generating questions that lead to the formation of a hypothesis. Section 2 Check
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Question 2 Which of the following is the group in an experiment in which all conditions are kept the same? A. standard B. independent variable C. experimental D. control Section 2 Check
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The answer is D. Conditions are kept the same in the control group
The answer is D. Conditions are kept the same in the control group. The experimental group is the test group. Section 2 Check
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SCIENTIFIC METHOD
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THEORY- Created when a hypothesis explains why things occur and continues to be supported by evidence gathered from other experiments (the most probable explanation for something) EX: BIG BANG THEORY, THEORY OF EVOLUTION
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LAW- Created when a hypothesis describes how things happen is continually supported by the data of other experiments (the definite why something happens) EX; LAWS OF MOTION
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Question 3 A scientist conducts an experiment to test the effect of light on plant growth. In each experiment, three plants of the same variety are each given 10 mL of water. One plant is exposed to full sunlight for 8 hours, one is exposed to full sunlight for 4 hours, and one plant is kept in a dark room. Plant height is measured after two weeks. What is the independent variable in this experiment? Section 2 Check
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Question 3 What is the independent variable in this experiment?
A. soil volume B. amount of sunlight C. plant height D. amount of water Section 2 Check
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The answer is B. The independent variable is the condition that is changed. In this case, the amount of sunlight is changed for each plant. Plant heights are measured results of the experiment, so plant height is the dependent variable. Section 2 Check
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Question 4 Compare the terms "theory" and "principle". Section 2 Check
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A theory is an explanation of a natural phenomenon that is supported by a large body of scientific evidence. A principle is a fact of nature, generally known to be true, such as the law of gravity. Section 2 Check
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Section 1.3 Summary – pages 19-23
Can science answer all questions? Some questions are simply not in the realm of science. Such questions may involve decisions regarding good versus evil, ugly versus beautiful, or similar judgements. Section 1.3 Summary – pages 19-23
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Section 1.3 Summary – pages 19-23
Can technology solve all problems? Scientific study that is carried out mainly for the sake of knowledge—with no immediate interest in applying the results to daily living—is called pure science. Section 1.3 Summary – pages 19-23
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Section 1.3 Summary – pages 19-23
Can technology solve all problems? Other scientists work in research that has obvious and immediate applications. Technology is the application of scientific research to society’s needs and problems. Section 1.3 Summary – pages 19-23
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Section 1.3 Summary – pages 19-23
Can technology solve all problems? Science and technology will never answer all of the questions we ask, nor will they solve all of our problems. Section 1.3 Summary – pages 19-23
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Question 5 Explain the difference between quantitative and qualitative information. Section 3 Check
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Quantitative information can be expressed numerically, and may also be used to generate graphs or tables in order to communicate data clearly. Qualitative information is not expressed numerically. Observational data and written descriptions of what scientists observe, are qualitative information. U.S. Students Enrolled in Physical Education Male Female Section 3 Check
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E. MICROSCOPES 1. Important Terms
Tool used to make enlarged images of microscopic organisms/cells. 1. Important Terms Magnification- the “power” of the scope to increase an objects apparent size
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The amount of area that can be seen at any given time
Field of View- The amount of area that can be seen at any given time
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Resolution- Refers to the ability to show detail clearly.
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The varying distances that the object is away from the microscope lens
Depth of View- The varying distances that the object is away from the microscope lens
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The power of the eyepiece X the power of the objective lens
Total Magnification- The power of the eyepiece X the power of the objective lens EYEPIECE OBJECTIVE LENS TOTAL MAG.
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2. Types of Microscopes: A. Light - light passes through specimen
B. Stereoscope - used to view macro-objects C. Electron- electrons bounced off/passed through specimen
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B. Stereoscope: (10X-60X) -Used to observe larger organisms -Often used when dissecting
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C. Electron Microscope: (up to 2 million x)
-Uses a beam of electrons focused on magnets to produce enlarged image -Specimens are coated with gold -Disadvantages: Cannot be used on living organisms Expensive Not in color Not seeing the actual specimen
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Types of Electron Microscopes
Transmission electron microscope (TEM) Scanning electron microscope (SEM) Scanning Tunneling Electron Microscope
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SEM TEM
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MEASUREMENT
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DERIVED UNITS Units based on the mathematical relationship between 2 derived units or 2 base units.
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Question 6 Which of the following is an SI unit? A. foot B. pound
C. second D. yard Section 3 Check
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The answer is C. Second is the SI unit of time.
SI Base Units Measurement Unit Symbol Length meter m Mass kilogram kg Time second s Electric current ampere A Temperature kelvin K Amount of substance mole mol Intensity of light candela cd Section 3 Check
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Conversion Practice EXAMPLES cm to in L to gal Km to m
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Review For Exam!
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