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Chapter 2 – Living Things. Use pages 32 – 40 to answer the following questions. Spontaneous Generation. 1. Living things arise from other living things through reproduction . * ALL LIVING THINGS MUST COME FROM OTHER LIVING THINGS!
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Chapter 2 – Living Things Use pages 32 – 40 to answer the following questions.
Spontaneous Generation • 1. Living things arise from other living things through reproduction. • * ALL LIVING THINGS MUST COME FROM OTHER LIVING THINGS! • Example: Puppies come from other dogs and ferns come from other ferns
Spontaneous Generation • 2. Spontaneous Generation: The mistaken idea that living things can arise from non-living things. • People used to think that moths came from clothes and maggots came from meat. • * We now know this is not true!!!!
Francesco Redi’s Experiment • Controlled experiment • Two identical jars with the same type of meat that were left in the same spot for the same amount of time • 4. Variable: The only thing that was different was one had a cover!
Redi’s Experiment: Step #1 Redi placed pieces of meat into two identical jars. He left one uncovered and covered one.
Redi’s Experiment: Step #2 After a few days there were maggots on the uncovered jar and none on the covered jar.
Redi’s Experiment: Step #3 Redi determined the flies had laid their eggs on the meat in the open jar and not in the covered. Redi concluded that decaying meat does not produce maggots.
Redi’s Experiment 5. Did Redi’s experiment prove or disprove spontaneous generation? EXPLAIN! His experiment DISPROVED spontaneous generation. There were no maggots on the covered jar, which means the flies could not get to the meat to lay their eggs.
Louis Pasteur’s Experiment • Mid – 1800s, Pasteur designed more controlled experiments to reject spontaneous generation • 6. He demonstrated that new bacteria appeared in broth only when they were produced by existing bacteria.
Controlled Experiment • A controlled experiment is an experiment in which only one variable is manipulated at a time.
8. About 2000 year ago, a Roman poet wrote these directions for producing bees. Why do you think reasonable people once accepted this idea? Recipe for Bees • Kill a bull during the first thaw of winter • Build a shed • Place the dead bull on the branches and herbs inside the shed • Wait for summer. The decaying body of the bull will produce bees.
What is Life? • 9. A CELL is the basic unit of structure and function in an organism. • All living things are made of cells!
10. How is unicellular different from multicellular? * Unimeans one, so unicellular means organisms made up of only one cell * Multi means many, so multicellular means organisms made up of many cells
Characteristics of Living Things • All living things must have all characteristics of living things • You can not have 3 out of the 4 and be considered living
CharacteristicsMrs. Carey’s Fabulous Four • GROWTH – All living things grow and change over time • REPRODUCTION – All living things must be able to make more of themselves * All living things must come from other living things! • RESPONSE – All living things respond to stimuli • METABOLISM – All the chemical reactions that take place in an organism (ENERGY)
12. What is homeostasis? • All organisms want to maintain stable internal body environment • Example: * What does your body do when it’s hot? * What does your body do when it’s cold?
Respond to Stimuli • All living things are going to respond to changes in their environment • Eye Demonstration: Working with a partner, have one partner shut their eyes and wait 30 seconds. When 30 seconds is up, the partner with their eyes open should watch the partner’s eyes who were closed. What do you notice? Switch roles and do this again.
13. Living Things Need…. • In order to survive, living things NEED some things for survival Homeostasis Living Things Need Water Food Living Space
14. Food Sources • Organisms can be autotrophs or heterotrophs • Autotrophs: Can make their own food INTERNALLY • Heterotrophs: Cannot make their own food *#15 – complete on your own!
