Questions
1. Models are analogies that allow us to clarify hypotheses-proposed explanations of relationships
between causes and effects. What roles do models play in testing hypotheses?
2. What did the humoral model of disease propose as the cause for cholera?
3. What did the miasma model of disease propose as the cause for cholera?
4. Unlike Snow's later work on cholera, his research on anesthesia was experimental in nature. What
general skills of experimental design were necessary to plan effective experiments to test dosage
measuring and delivery systems for anesthesia, or to investigate the properties and effects of different
drugs?
5. Why are experiments considered strong tests of hypotheses?

1. true.2. true.3. true.4. false.5. true.the concept of darwin's theory of evolution involves the idea that there are limited resources in a given living environment and that the organisms which live within have variations in their genetic make up due to random mating. the ones with beneficial genetic variations can express certain traits which give them an upper hand in surviving and reproducing in the said environment compared to ones who may have a more disadvantageous variation in traits. over time, the organisms with an upper hand will survive and reproduce more frequently and pass on their beneficial genes while the others die. the result is evolution, where we observe (usually, but not always) eventually, phenotypic distinct changes.

Idont really understand