What is the relationship between inference and observation? Scientific practice and the Cell Theory

Where did the cell theory come from?

Observation Information gathered from your 5 senses Hearing, sight, smell, taste, touch Two types of observations Qualitative - Quality of the object like color, texture, relative size, etc. Quantitative – measurable quantity like the number of objects, the length, weight, time to perform an action, etc.

What were some observations that the Cell Theory scientists had? Jansen - two curved lenses together make objects appear even larger than one curved lens. (inventor of first compound microscope) Leuwenhoek – Saw little animal shaped living organisms - animalcules Hooke – Saw little rectangular shapes in cork. Coined the term “cell” Schleiden – Every plant slide had cells in it. Schwann – Every animal slide had cells in it.

Inference observation + background knowledge Schleiden – Since all plant slides had cells, he used his previous knowledge and inferred that all plants are made of cells. Schwann – Since all animal slides had cells, he used this previous knowledge to infer that all living things are made of cells

Practice Observations Inferences

More practice Observations Inferences

How is an inference different than a prediction? Inference is concerning the present. A prediction is about an occurrence that could happen in the future. Both are still based on observations.

Practice Observations Inferences Predictions

Theory vs. Law blob:https%3A// Laws describe specific relationships in nature. It DOES NOT attempt to explain them. Example: Law of conservation of mass. (matter is not created nor destroyed) Theories are well supported explanations of relationships in nature. Example: the cell theory, the sliding filament theory for muscle contraction, etc. Theories DO NOT become laws.