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Chapter 1. Objectives Apply the Scientific Method to Solve a problem. List the Characteristics of Living Things Understand Homeostasis Compare a Hypothesis and a Theory. Vocabulary. Create a flap book for the following terms: Hypothesis Theory Succession Statistical Variability
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Chapter 1 Objectives Apply the Scientific Method to Solve a problem. List the Characteristics of Living Things Understand Homeostasis Compare a Hypothesis and a Theory
Vocabulary Create a flap book for the following terms: • Hypothesis • Theory • Succession • Statistical Variability • Controlled Test • Observation
INTERACTIVE Quickwrite: In your own words, What is Biology?
Biology The Study of LIFE
INTERACTIVE • What makes something alive??? • Think, discuss, pass the pen
Characteristics of Life • Biologists have established that all living things share 7 Characteristics of Life.
Organization and Cells • All living organisms (one celled or multicellular) have some degree of organization. • CELL—smallest unit of life • UNICELLULAR—one celled organisms • MULTICELLULAR—made up of more than one cell • Complex Multicellular organisms (such as humans) have ORGAN SYSTEMS, groups of parts that carry out specific functions. • ORGANS are structures that carry out specialized jobs within an organ system.
Organization and Cells • All organs are made up of TISSUES, or groups of cells with similar functions. • Tissues are made up of CELLS. • ORGANELLES are within each cell and are tiny structures that carry out functions necessary for the cell to stay alive. • Organelles contain BIOLOGICAL MOLECULES, the chemical compounds that provide physical structure, movement, energy. • Biological Molecules are made up of ATOMS, the simplest particle of an element.
Response to Stimuli • An organism can respond to a STIMULUS or physical/chemical change in the internal or external environment. • Example—an owl dilates its pupils to keep the amount of light entering the eye constant and therefore maintain good vision.
Homeostasis • The maintenance of a stable level of internal conditions even though the environment is changing. • Examples: Maintaining body temperature, water content, nutrients within a cell • GOLDFISH LAB
INTERACTIVE • Observing Homeostasis with Goldfish!
Metabolism • Living organisms use ENERGY to repair, move, and grow. • Metabolism is the sum of all the chemical reactions that take in and transform energy and materials from the environment. • Example—plants use the sun’s energy to generate sugar molecules through photosynthesis. • Example—an owl’s metabolism allows the owl to extract chemicals in its prey and use it as energy to fuel growth.
Growth and Development • All living things grow and increase in size. • Living things grow from the results of divisions and enlargements of cells. • Unicellular—enlargement of cells • Multicellular—division of cells • Development is the process by which an organism becomes a mature adult.
Reproduction • All living organisms produce new organisms in a process called reproduction. • Reproduction (unlike the other characteristics is NOT essential for life of a single organism, however it is essential for the continuity of the species) • During reproduction organisms transmit hereditary info to their offspring. This info is encoded in DNA (deoxyribonucleic acid). • A short segment of DNA contains instructions for a single trait (like eyecolor), this is called a GENE.
Change through Time • Basic genetics do not change through time • Populations of living organisms evolve or change through time to survive
Song—Characteristics of Living Things • Which characteristic is missing??
INTERACTIVE • Is it alive?
Science as a Process • Science is characterized by an organized approach…the SCIENTIFIC METHOD. • Quickwrite…What do you know/remember about the Scientific Method??
Scientific Method Observation/Question Hypothesis Experiment Data/Results Conclusion
Observations • Science starts with observation • Observation involves using the 5 senses to gather information • Can be quantitative (numbers) or qualitative (not numerical, more descriptive) • All of this information is gathered as DATA, or evidence • What are the 5 senses??
INTERACTIVE • Guess What Activity
Interpreting the Evidence • Scientists must make inferences based on the observations. • Inferences are a logical, unbiased, interpretation based on prior knowledge, experience, and observation • Examples of Inferences: • You see a broken window and a baseball laying on the floor under the window. You INFER that the baseball broke the window.
INFERENCE - a logical interpretation based on prior knowledge * Drawing a conclusion
Explaining the Evidence • A HYPOTHESIS is a possible explanation or answer to a scientific question. • A Hypothesis must be TESTABLE. • Examples: 1. Purina food will reduce a dog's shedding. 2. Putting Miracle Grow on tomato plants will make them produce more tomatoes. 3. The drug Avapro will lower a person's blood pressure.
Examples of Hypotheses Examples
INTERACTIVE • Write a hypothesis for the experiment below: • A scientist is going to measure toy car speed on a ramp. He is going to test if the size of the wheel affects the speed of the toy car going down a ramp. He has a regular toy car, a toy car with extra large wheels, and a toy car with mini-wheels. • What is your hypothesis??
Identify the GOOD hypothesesCopy the good hypotheses and explain why it is good. • Plants will grow taller with sunlight. • Boys like video games. • 9th graders are smarter than middle school students. • Dogs will run faster after eating a bone. • Bounty paper towels are stronger than the store brand. • Cats are good mouse hunters.
Setting up a Controlled Experiment • A controlled experiment is a test of a hypothesis with only one variable being tested. • Manipulated (Independent) Variable is the part of the experiment that is being deliberately changed by the scientist. • Responding (Dependent) Variable is the part of the experiment that that changes as a result of the experiment. • Controlled Variables: items that stay constant throughout the experiment (example: the materials used)
INTERACTIVE A scientist is going to measure toy car speed on a ramp. He is going to test if the size of the wheel affects the speed of the toy car going down a ramp. He has a regular toy car, a toy car with extra large wheels, and a toy car with mini-wheels. What would your hypothesis be?? What would the Manipulated/Independent Variable be?? What would the Responding/Dependent Variable be??
INTERACTIVE 2 • Your group will be given a scenario. • Read it aloud. • Answer the questions your notes. • When time is up, rotate the scenarios and repeat.
Recording and Analyzing Results • Scientist keep written records of all observations and data, often in a journal, notebook, or computer.
Error • No experiment is perfect. Many things can go wrong and many things cannot be controlled. • Scientists acknowledge that there will be error. • Scientists ALWAYS identify and communicate sources for error.
Drawing a Conclusion • Scientists then use the data and results from an experiment to evaluate the original hypothesis and develop a conclusion. • Look at pages 14-15 in your textbook, study the pictures and captions on the Owl. Be ready to answer the following: • What was the question? • What was the control? • What was the variable? • What was the conclusion?
Publishing • If evidence supporting a hypothesis builds up from many, many experiments by many scientists, the hypothesis becomes a THEORY. • A THEORY is a well-tested explanation or answer to a problem.
INTERACTIVE • Can your procedure be replicated??
INTERACTIVE • Quickwrite: In your own words explain the difference between Hypothesis and Theory.
Light Microscope • To see small organisms and cells scientists usually use LIGHT MIRCROSCOPES. • A compound light microscope has 2 lenses to magnify an image. • 4 major parts to a light microscope: • Eyepiece • Objective lens • Stage • Light Source
Magnification and Resolution • Magnification– The increase in the objects apparent size • Example: 10x means 10 times the objects real size. • Resolution: the power to show details clearly (how focused it is)
Electron Microscope • To examine cells in great detail or study cell parts or viruses, scientists use Electron Microscopes. • Very powerful magnification and resolution. • Always in black and white (computers can add color)
Metric System • Scientists use a common measuring system so they can compare and understand results. • Called SI or Metric System
Assessment • Chapter Review, pages 25-27