2. I. History A. Spontaneous Generation ( Abiogenesis) 1. 1 st proposed by Aristotle 2. Believed that complex, living organisms are generated by decaying organic substances, Example: mice would spontaneously appear in stored grain OR maggots would spontaneously appear in meat.

3. I. History (con’t) A.Spontaneous Generation (Abiogenesis) 3. Was widely believed until the 19 th century. 4. Several scientists performed experiments that disproved spontaneous generation Francisco Redi Lazzaro Spallanzani Louis Pasteur The Characteristics Common to Life

4. Pasteur’s Experiment Proved Biogenesis Louis Pasteur 1859 B. Biogenesis – all living organisms come from pre-existing living things.

5. - Anything that possesses the following characteristics of life is called an organism.

6. I. Common Characteristics of Life A. Made of Cells – organized from the cell up B. Reproduction ( asexual or sexual) C. Grow and Develop D. Adaptation to environment E. Maintain Homeostasis F. Based on a universal molecular code (DNA) G. Obtain and use materials and energy (ATP)

7. A. Cells – The Basic Unit of Life  An Amazing Fact: THE HUMAN BODY …  … is a collection of a trillion, diverse and highly organized cells.  What does it takes to keep this collection of a trillion cells “alive” ?  A combination of Biology … Chemistry … Genetics … Physics …

8. C. Reproduction - All living organisms are able to reproduce themselves Asexual – DNA from only 1 parent Sexual – DNA combining from 2 parents Binary Fission Spore Formation Hydra Budding Sperm fertilizing egg Asexual Sexual

9. C. Growth and Development  Unicellular organism  Growth … an increase in the size of the cell  Development … an increase in the # of organelles in the cytoplasm  Multicellular organisms  Growth... An increase in the # of cells  Development … Cells specialize / diversify and form tissues, organs, and organ systems

10. D. Adaptation  All organisms are able to adapt to their surroundings...  To be able to …  respond to stimulus and react!  Examples…?

11. E. Homeostasis  The ability of an organism to maintain a relatively constant internal environment that is suitable for the life of its cells.  Sweating…shivering…increased respiration…being thirsty … etc.

12. II. Tools of Science A. Common Measurement System = SI “The Metric System”- based on a system of 10 Length – meters Volume – liters Mass – grams Temperature – centigrade Prefixes added to the basic units above: milli = 1/1000 centi = 1/100 kilo – 1000

13. II. Tools of Bio-Sciences B. Microscopes 1. Light – compound microscopes 10X (eyepiece) 10X, 40X, objectives 2. Electron Microscopes TEM – transmission electron microscope (detailed interior picture) SEM – scanning electron microscope (detailed 3-D exterior pic.)

14. F. A Common Hereditary Thread  DNA – the molecule that is common to all living organisms  Provides the code for making all the diverse proteins necessary for cell life

15. III. Laboratory Techniques  Wet Mount Slide  Adding a liquid to a dry specimen on a slide and using a cover slip to protect liquid from microscope objectives  Cell Cultures  Growing groups of cells from one parent cell  Cell Fractionation  Separating and collecting only one part of a cell

16. SI Measurements – prefix “ladder” 1,000,000Mmega 1,000kkilo 100hhecto 10Ddecka 1base units: meter, liter, or gram.1ddeci.01ccenti.001mmilli.0000001micro.0000000001 nnano 1 x 10 -12 ppica