Biology & The Characteristics of Life Name: Period: Date: I. What is BIOLOGY? The study of WHAT IS THE VALUE OF BIOLOGY? Biological principles are daily being applied for the in controlling disease, improving health, developing better foods, conserving natural resources, and understanding our environment WHY DO WE STUDY BIOLOGY? Industry, agriculture, government, and the medical profession provide unlimited to young people with a biological background. Students find that biology offers many interesting and rewarding as giving them a better understanding of themselves and a greater of the living things that surround them. as well HOW DO WE STUDY BIOLOGY? Biology students should be and use careful judgment. A healthy, believer in cause and effect, and order in nature is imperative. ANSWER THE FOLLOWING INTRODUCTORY QUESTIONS: 1. How would you define the word LIFE to a young child? 2. What is the basic unit of life? 3. Do you believe there IS life elsewhere in the universe? Explain your answer. 4. List some activities of living things. 1
II. 8 Characteristics of Living Things: 1. Made of one or more : = basic unit of structure and function of all living things Unicellular-bacterium, paramecium, amoeba Muticellular-humans, snakes, plants, etc. 2. : Each organized structure in an organism has a specific Ex: an anteater s snout functions as a container for its long tongue All parts form an functioning unit 3. : Species must replace themselves Is necessary for the survival of the organism; it is needed for the survival of the! 4. : Living things grow because their CELLS grow and divide! = the increase in living material (cellular mass) and the formation of new structures = the changes that take place during the life of the organism. 5. Responds to Stimuli: = a condition in the environment that creates a response from the organism. o Ex: temperature, weather, other organisms, etc.. = the reaction to a stimulus o Critical for the safety and Ex: = shark smells blood in the water; = shark moves quickly toward the blood and attacks any organism present of an organism! 6. Requires : = the ability to do work or to make things move. o Powers life processes 2
o Maintains,,, and. o Obtained from the own!) o Main source of energy for all life is the they eat. (plants make their o Energy not only flows through the organism, but also through the community. 7. Maintains Homeostasis: = the regulation of an organism s internal environment to maintain conditions that allow it to live. o Ex: Human s and, help the body maintain its proper -regulated by the hypothalamus o Ex: hormones of the blood- regulated by o Ex: regulation for nerve and muscle function- regulated by the kidneys and intestine o Ex: the pancreas/insulin balance-regulated by o Ex: balance-regulated via food/water intake and waste elimination 8. Adaptations Evolve Over Time: = are inherited changes in structures, behaviors, or internal processes that enable an organism to respond to stimuli (survive). o Structure and behavior examples: Long hind legs enable rabbits to quickly avoid predators; fur to body temperature; changing fur color for the different seasons o Internal stimuli examples: balance, balance and Motion vs. Locomotion what is the difference? Motion = Locomotion = 3
III. Basic Needs of Life: 1. Energy Main source of energy > Plants get energy directly from the sun get energy from dead animals and plants Animals get energy from eating or an organism that eat plants 2. Water, Oxygen, and Minerals Most organisms need Living things are made up of about in order to survive water The Nature of Science: answer questions about the natural world. = Continuous process that seeks to Science only deals with things that are TESTABLE! 1. Science is subject to. - Pulling medicine off shelves because researchers found out it harms people. - Scientists thought the world was once flat - Pluto is not longer considered a planet 2. Does not always provide complete answers to all questions. - What happened to the dinosaurs?; no one knows for sure! 3. Science demands i.e. DATA!!! 4. - What certain medicines will treat - Doctors and scientists have to think on their feet; not all cases are the same for Dr. s and scientist have to be able to trouble shoot. 5. Explains and predicts 6. Scientist try to identify and AVOID 4
Theory vs. Law = is an explanation based on many observations (hypothesis is repeatedly verified over time and through may separate experiments) o Enable scientists to predict new facts and relationships of natural phenomenon o Often revised as new information is gathered. o Ex: Cell Theory, Theory of Evolution = describes relationships under certain conditions in nature o Describes but does not explain a natural event o Ex: Law of Gravity; Law of Conservation of Matter 6 Steps of the Scientific Method: 1. State the - Ex: How does red light effect plant growth? 2. Gather - About the 3. Form a - A must be: Related to the Written in., format Ex: If a plant is placed under red light, then the plant will not grow very tall. 4. Perform the A. Make!! B. Choose the variables: a) Your variable is the factor that you will 5
change in your experiment. (the factor being tested) NOT controlled or influenced by something else Ex: b) The variable is what you predict will change as a result of variation in your experiment. IS controlled or influenced by something else (independent variable) Ex: Note: the independent variable influences the dependent variable! c) A The standard of comparison. is a group that serves as a It is exposed to the same conditions as the treatment groups except for the being tested. C. Decide the number of o Ex: a plant placed in exposed to red light) are the repetition of an experiment (trials) and the same conditions are kept in the experiment. o Provides better statistical data (averages) (not D. Specify the The DO NOT What your are asking. in an experiment are the factors that. (Ex: temperature, equipment, etc.) will be will depend on what question you Ex: type of plant, amount of water, type of soil, amount of fertilizer, keeping plants at same temperature, same size pots, etc. 6
5. Collect and analyze the 6. Draw - Describe what happened - Restate the - Explain the results using the and - Propose an based on the data that was collected 7
The way that scientists answer questions is through an organized series of events called scientific methods. There are no wrong answers to questions, only answers that provide scientists with more information about those questions. Questions and collected information help scientists form hypotheses. As experiments are conducted, hypotheses might or might not be supported. Observe an unexplained phenomenon. Collect information. Make observations. Ask questions. Use prior knowledge. Review related research. Form a hypothesis. Design an experiment to test the chosen hypothesis. Conduct an experiment and record the data. actual results. Compare expected results. Repeat experiment many times until results are consistent. Draw a conclusion. Refine and test an alternate hypothesis. Hypothesis is supported. Report results of the experiment. Hypothesis is NOT supported. Compare results from similar experiments. accepted hypothesis. Leads to additional experimentation based on accepted hypothesis. 8
Applying The Scientific Method Worksheet Name: Period: Date: PART 1: Vocabulary: Answer the following questions completely and concisely. 1. List the 6 steps of the scientific method. a. b. c. d. e. f. 2. What is a hypothesis? 3. How should all hypotheses be written? 4. What is the difference between an independent variable and a dependent variable? 5. What is a control? 6. What is a constant? 7. What are three examples of constants in an experiment? 9
PART 2: Analysis: Answer the following questions completely and concisely. A student noticed that when a dog is cut, the dog periodically licks its wounds. Usually after a few days, the wound begins to heal without ever showing signs of infection. The following steps outline the student s line of reasoning: A. I wonder why the dog s wound doesn t become infected. B. If dog s saliva is present, then the growth of infection-causing bacteria will be prevented. C. I ll obtain a bacterial culture and grow the same kind of bacteria in two identical culture dishes. Once the bacteria start growing, I ll add dog saliva to ONLY one of the dishes and leave the other alone. I ll cover both dishes. Then I ll observe what happens each day for one week. D. Even after adding the dog saliva to one of the dishes, the bacteria continued to grow in both dishes over the course of the week. However, the bacteria in the dish treated with saliva grew more slowly than the bacteria in the untreated dish. E. I think I ll try something else. I ll start with two identical culture dishes, as before, and use the same kind of bacteria in each dish, but this time I ll treat one dish with dog salvia BEFORE I add the bacteria. I ll observe what happens each day for a week. 1. What part of the scientific method is illustrated in step A? 2. What part of the scientific method is illustrated in step B? 3. What part of the scientific method is illustrated in step C? 4. What is the independent variable in the student s experimental design? 5. What is the dependent variable in the student s experimental design? 6. What is the control in the student s experimental design? 7. Why were both dishes covered? 10
Review of the Characteristics of Life Name: Period: Date: Directions: Answer the following questions specifically and concisely. 1. What is biology? 2. What is a cell? 3. is the ability to do work. 4. What is the main source of energy for all life? 5. is a condition in the environment that creates a response from an organism. 6. What is the difference between motion and locomotion? 7. What is homeostasis? 8. What is an example of how our body maintains homeostasis? 9. is an increase in living material while, is the changes that take place during the life of an organism. 10. What is the nature of science? 11. List an example of how science is subject to change. 12. List an example of how science does not provide complete answers to all questions. 13. Fire has some of the characteristics of life (reproduces, needs energy, responds to stimuli). Why is it considered non-living? 11
Review of the Scientific Method Part 1: Put the following steps of the scientific method in the proper order. Organize and analyze data State a hypothesis Identify the problem State the conclusion Design and carry out an experiment Make observations and record data Gather information Part 2: Match the definition with its term. A. Suggested explanation to a problem based upon known information that is testable B. A variable that is not controlled or influenced by something else. C. Factors that are not changed during the experiment D. Observation and measurements made during an experiment E. Part within the experiment that is maintained without change in order to provide a comparison for what is being tested F. Hypothesis that has been tested and supported by a great amount of evidence over a long period of time G. Statement describing (but not explaining) a natural event or phenomenon H. Logical explanations based on observations and experiences I. A summary that explains whether or not the data supports the hypothesis 1. Theory 2. Law 3. Hypothesis 4. Experiment 5. Constants 6. Control 7. Data 8. Conclusion 9. Inference 10. Dependent Variable 11. Independent Variable J. A variable that is controlled or influenced by something else K. Used to test a hypothesis 12
Characteristics of Life & The Scientific Method Vocabulary: 1) Biology = study of life 2) Cell = basic unit of structure and function of all living things 3) Energy = the ability to do work 4) Homeostasis = the regulation of an organism s internal environment to maintain conditions that allow it to live 5) Nature of Science = Continuous process that seeks to answer questions about the natural world. 6) Growth = the increase in living material (cellular mass) and the formation of new structures 7) Development = the changes that take place during the life of the organism 8) Stimulus = a condition in the environment that creates a response 9) Adaptations = are inherited changes in structures, behaviors, or internal processes that enable an organism to respond to stimuli (survive) 10) Motion = movement or gestures 11) Locomotion = the ability to travel from place to place 12) Hypothesis = testable explanation; written in IF THEN format 13) Inference = Logical explanations based on observations and experiences 14) Independent variable = the factor that you will change in your experiment 15) Dependent variable = what you predict will change as a result of variation in your experiment 16) Control = a group that serves as a standard of comparison 17) Replicates = are the repetition of an experiment (trials) and the same conditions are kept in the experiment. 18) Constants = the factors that DO NOT change in the experiment 19) Theory = is an explanation based on many observations (hypothesis is repeatedly verified over time and through may separate experiments) 20) Law = describes relationships under certain conditions in nature; Describes but does not explain a natural event 13