What is Life?

1. What is Life? OR The elusive phenomenon of life

2. Historically… • Living systems were distinguished because they contain a “vital force”

3. Today • We now know there is not 1 substance or force that is unique to life. There are 7 characteristics to define living things • Biologists see its ancient molecular origins and its degree of organization.

4. Characteristic 1 • Life is highly organized and complex. Evidence:1. biochemical structure of life is complex 2. made of cells - structure, function and reproduction 3. depends on other life forms through recycling 4. each organism is recognized by its characteristic appearance and structure

5. Characteristic 2 • Living things have metabolism – the sum of all chemical activities in a living system Evidence: 1. obtains and uses energy from the environment; is classified based on food getting strategies 2. Energy is used for growth, repair, maintenance and to increase the high degree of orderliness of the body

6. Characteristic 3 • Life responds to environmental stimuli: living things respond to physical and chemical changes in the environment-- or else they die! Evidence: 1. Movement to light or away from stimuli 2. Changes in temperature, pressure, sound, water, air, soil

7. Characteristic 4 • Living things grow and develop (change) Evidence: there is an increase in the amount of living material and an increase in the complexity of the organism over time

8. Characteristic 5 • Life can maintain homeostasis. • An organism carefully and constantly regulates and maintains metabolic processes in a balanced state by adjusting to changes Evidence: 1. adjusts to changes in temperature, light, pressure, damage

9. Characteristic 6 • Life can reproduce – make an exact or similar copy of itself – asexual or sexual Evidence: 1. All life comes only from other life 2. The information for “life” is in the genetic material (DNA) which is passed from generation to generation

10. Characteristic 7 • Life can adapt or evolve Evidence: 1. Organisms/species change or adapt to their environment which increases survival 2. Can be structural, physiological, behavioral OR a combination… 3. Populations can evolve or change over time (individuals DO NOT evolve). A population becomes a collection of the coordinated adaptations of the members

11. Rally Coach: 1. Car 2. Apple 3. Poop 4. Butterfly 5. Computer 6. Pencil • 1.iPhone • 2. Televison • 3. Turtle shell • 4. Bacterium • 5. Boogers • 6. Tupac

12. Alive? • Dead? • Nonliving? • Product of Life? • Dormant?

13. Characterizing Objects Lab • Purpose/Problem: To characterize objects through observations and classify them as: alive dead non-living dormant product of a living organism

14. Research/Hypothesis: • Define the terms listed in the purpose/problem section.

15. Experiment: A. Equipment and Materials - objects to characterize in lab, paper, pencil B. Procedure - observe an object and characterize it using terms from Purpose/Problem

16. Data: Create a chart Specimen/Object Characterization

17. Conclusion: Use the 3 part form Introduction - Start with an opening sentence that grabs the reader (related to lab content)…then tell what you did and why you did it.

18. Conclusion: Use the 3 part form Body - discuss each observation Use the data as evidence for your analysis

19. Conclusion: Use the 3 part form Summary - explain how this information can be used, indicate places where errors took place, and discuss changes that could make the experiment more valid.