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

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

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.

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

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

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

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

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

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

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

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

Alive? Dead? Nonliving? Product of Life? Dormant?

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

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

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

Data: Create a chart Specimen/Object Characterization

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.

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

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.