Chapters 1: The Science of Life

1. Chapters 1:The Science of Life Mountain Pointe High School Science Department

2. Section 1 The World of Biology Chapter 1 Objectives • Relate the relevance of biology to a person’s daily life. • Describe the importance of biology in human society. • List the characteristics of living things. • Summarize the hierarchy of organization within complex multicellular organisms. • Distinguish between homeostasis and metabolism and between growth, development, and reproduction.

3. The Science of Life An adult snowy owl is white. What is the adaptative value of baby animals having different coloring than their parents?

4. Why study Biology? • Biology is the study of life and can be used to both solve societal problems and explain aspects of our daily lives. • Millions of life forms haven’t even been discovered yet. • Living things don’t exist in isolation - they depend upon other living & nonliving things. • The future health of our planet and our species depends upon our understanding of biology.

5. The Science of Life The tropical rain forest produces products like: nuts, bananas, coffee, tea, rubber, exotic woods, and chocolate. We greatly depend on the production of oxygen from the green plants. How does the tropical rain forest depend on us? Carbon dioxide used in ?????

6. All living things share 7 common characteristics: • Living things share the same 7 characteristics: • Cellular organization • Response to a stimulus • Maintain homeostasis • Metabolism • Grow and develop • Reproduce • Change through time

7. Characteristics of Life • Anything that possesses all of the characteristics of life is known as an organism.

8. Living Things Are Organized and are made of Cells • They all show an orderly structure. • They all have specialized parts that perform specific functions. • They all are either unicellular (one cell) or multicellular (more than one cell). • What is the order of organization of a human (from smallest to largest living structures)? • Cells -> Tissue -> Organs -> Organ Systems -> Organism

9. Living Things Respond to a Stimulus • An organism’s reaction to a stimulus is known as a response. • Stimulus: a physical or chemical change in the internal or external environment. • Any structure, behavior, or internal process that improves an organism’s chances for survival is an adaptation. • Example: If you place your hand on a hot object you respond by pulling your hand back.

10. Living Things Can Maintain Stable Internal Conditions or Homeostasis • Environment - all living & nonliving factors that affect an organism. • Environmental condition, internal or external, may require an organism to adjust or maintain a stable condition. • Example: Why does your body sweat? Why would painting your entire body with oil paint kill you?

11. Living Things Use Energy to Power all the Life Processes • Metabolism • Metabolism is the sum of all the chemical reactions that take in and transform energy and materials from the environment. • Life Process: repair, movement and growth

12. Living Things Grow and Develop • Growth – the division and enlargement of cells resulting in an increase in the amount of living material & the formation of new structures. • Development - all of the changes that occur during an organism’s life resulting in a mature adult.

13. Living Things Reproduce • Similar-looking organisms that can interbreed & produce fertile offspring are known as a species. • Living organisms pass on hereditary information from parents to offspring, also called reproduction. • Without reproduction, a species becomes extinct.

14. Populations Change Through Time • Populations of living organisms evolve or change through time. • Why is this important? • For a species survival in a changing world. • This explains the diversity of life-forms on Earth. Click e for video -

15. Section 3: The Study of Biology Section Objectives • Outline the main steps in the scientific method. • Summarize how observations are used to form hypotheses. • List the elements of a controlled experiment. • Describe how scientists use data to draw conclusions. • Compare a scientific hypothesis and a scientific theory. • State how communication in science helps prevent

16. The Scientific Method A step-by-step process used to solve problems.

17. 1. Observation: this causes a proposed question. (A problem needs to be solved in the form of a question.) Note: Information needs to be gathered about the questioned 2. Form a hypothesis; a possible solution to the question asked or problem statement. 3. Prediction: what would happen in a test situation if the hypothesis were true. 4. Experiment: Test yourhypothesis(design an experiment). 5. Analysis & Conclusions: Analyze your test results and draw a conclusion. Was your hypothesis correct or not? 6. Conclusions and Data are communicated to scientific community (published). Click e to activate movie ------- Steps In The Scientific Method

18. The Parts of An Experiment • Experiment - testing a hypothesis by collecting information under controlled conditions. Two groups: • 1. Control Group - all conditions are kept the same. • 2. Experimental Group - all conditions are kept the same except the single one that’s being tested. Click the e to activate a movie -

19. The Parts of An Experiment • It’s important that in a controlled experiment, only one condition is changed at a time. • The condition that changes is called the independent variable. • The condition that results from changing the independent variable is known as the dependent variable.

20. An Example of an Independent Variable • In an experiment designed to test the effectiveness of a flea powder, the amount of flea powder applied to dogs would be an example of an independent variable. Some dogs get more, others less.

21. An Example of a Dependent Variable • The number of fleas detected on each dog over the next few days, weeks or months would be the dependent variable in this experiment. Click e below to view movie:

22. The Development of Theories • A hypothesis that is supported by many separate experiments over a long period of time is known as a theory. • Examples: • - Theory of Evolution • - Big Bang Theory