1. SCIENTIFIC THEORIES AND THEIR EVIDENCE

2. Cell Theory What is Cell Theory? Cell Theory: Evidence:
All living things are made up of one or more cells. All cells arise from existing cells. The cell is the basic unit of structure and function for all organisms.
Evidence:
First formulated in 1839
Began from the work of three scientists: Schleiden, Schwann and Virchow
Has since been verified by 1,000’s of scientists
Begin by asking students, “What is Cell Theory”? Discuss with them, and determine their background knowledge before sharing the rest of the information on the slide.

3. Evolutionary Theory What is the theory of evolution? Evidence:
Change in the heritable characteristics of a population across successive generations
Evidence:
Work of Charles Darwin (Finches)
Fossil Record
DNA Sequencing
Anatomical Similarities between life forms
Begin by asking students, “What is Evolutionary Theory”? Discuss with them, and determine their background knowledge before sharing the rest of the information on the slide.

4. What is Gene Theory? What is Gene Theory? Evidence:
Traits are passed from parent to offspring via genes.
Evidence:
Work of Gregor Mendel on pea plants and other organisms
1,000’s of scientists, since Mendel’s time, have conducted experiments that confirm this theory
New DNA technologies continue to confirm this theory and help us learn more about the role of genes in some diseases.
Begin by asking students, “What is Gene Theory”? Discuss with them, and determine their background knowledge before sharing the rest of the information on the slide.

5. Germ Theory of Disease What is Germ Theory of Disease? Evidence:
Microorganisms are the cause of some diseases.
Has led to important things such as antibiotics and good hygiene practices
Evidence:
Resulted from the work of numerous scientists, but is mainly attributed to the work of Louis Pasteur and Robert Koch
Microscopic observations and experimental evidence since late 1800’s continues to confirm this theory.
Begin by asking students, “What is Germ Theory”? Discuss with them, and determine their background knowledge before sharing the rest of the information on the slide.