1. BIOLOGY THE STUDY OF LIFE Chapter 1

2. WE LIVE IN THE BIOSPHERE THIN LAYER OF AIR, LAND AND WATER HOME TO ALL LIVING THINGS ON EARTH MAKES UP <1% OF EARTH’S MASS

3. WHAT IS AN ORGANISM? Any living thing Which of these are alive?

4. Do organisms arise by Spontaneous Generation? Spontaneous generation (SG) is life from nonlife. Francesco Redi disproved SG of maggots on meat in 1668. Louis Pasteur later disproved SG of bacteria in the late 1800’s.

5. Biogenesis Life from life Except for the first cells, all cells and living things came from pre-existing cells.

6. HOW DO WE KNOW THAT SOMETHING IS ALIVE? Organization Use energy Grow Develop Reproduce Respond to environment Adaptation

7. Organization Unicellular or multicellular Specialized structures Cell is basic unit of structure and function

8. Energy Energy exists in many forms – chemical, light, sound, heat Organisms use light energy to make food, to see, for warmth All energy for living things is traced back to the sun Plants use sunlight to make food Other organisms eat the plants to get energy

9. Growth and Development Growth – increase in size Development – change in form or shape Amount of growth varies in different organisms Nature of development varies from species to species

10. Reproduction Process by which new living things are produced Makes new cells Necessary for the survival of the species Offspring can be duplicates of the parent or can be different from parent(s)

11. Response and Adaptation Response = reaction to a stimulus in environment Adaptation occurs within the entire population of organisms – responses to long-term changes in the environment; passed on to future generations.

12. Cells Smallest unit of life that exhibits all the characteristics of living things Within cells are organelles – specialized structures

13. Levels of Organization Atom Cell Tissue Organ Organ system Organism Population and community Ecosystem Biopshere (Ecosphere)

14. Adaptation and Interdependence Long-term changes Charles Darwin – Theory of Evolution by Natural Selection – explained how organisms could change and could pass those traits on to their offspring.

15. Interconnections between organisms Complex relationships occur between organisms living in same habitat Predator-prey Symbiosis –Mutualism –Commensalism parasitism

16. Even a small change to one type of organism can affect the other organisms in an environment –Can cause other organisms to change –Organisms that can’t adapt fast enough might become extinct

17. Role of humans in the web of life Look around – name the objects you see that are living, made from living things, or made from products of living things. Food Medicine Clothing resources

18. Scientists use careful observation and controlled experiments to study the natural world Careful observations – include smell, sound, sight, measurements, and careful recording Scientific Method –Make predictions – hypothesis –Design experiment –Carefully observe that experiment –Interpret the results –Draw conclusions

19. Observations Use human eye Use tools to aid the eye – ex – microscope, Geiger counter, etc. Measurements are in metric system – never use inches and other English units to report your results!

20. Hypothesis Possible explanation for an event or set of observations Proposed before the experiment is carried out. Educated guess

21. Experiment Focuses directly on problem being studied Needs hypothesis at start One variable Two or more groups – one control, others with a variation of the test subject (these are called experimental groups). Results must be accurately reported

22. Theory Hypothesis that is supported by many experiments done over a period of time Not facts, but are probable explanations for events that are supported by a wide range of evidence. New evidence can disprove a theory

23. Issues in Biology – Science in Society Ethics and values cannot be tested scientifically Experimental results must be made public so that they can be verified – Peer Review Public policy often relies on scientific data. Much experimentation is funded by public money – supported by tax dollars.

24. Design a scientific investigation Do seeds need light to germinate (sprout)? –Propose a hypothesis – always written as a statement, not a question. Ex – seeds need light to germinate. OR seeds do not need light to germinate –Use materials provided to perform an experiment –Record results –Report data (must be measurable)

25. Write a Lab Report Introduction – give some background on the subject being studied – look up in your book what seeds need to germinate Purpose – state why this experiment is being done Hypothesis – predict what you think is going to happen Materials – list in columns, not a paragraph

26. Procedure –Number each step (like in a cookbook) –Give specific instruction about what has to be done to duplicate this experiment (pretend you are writing this for a really dumb biology teacher) –Never use “I”, “You”, “Your”, etc. –Don’t include such things as: Gather the equipment Use pencil and paper to record results

27. Results – these always go after the procedure, never at the end of the lab report. –These should include observations and measurements (never in paragraph form) – use columns, tables, etc. –Use a ruler or the computer – do not hand draw lines for columns or tables –Graphs should be traditional, not 3-D or hard to read computer-generated graphs

28. Conclusions –Explain how the results supported or did not support hypothesis –If no hypothesis, explain what you learned by performing this lab –If there are any analysis questions, these go after your conclusions.

29. The End