Cell Theory and Biological Organization

A comprehensive set of vocabulary flashcards covering the history of cell theory, key scientists and their contributions, and the postulates of modern cell theory.

Average human cell count

An average human is thought to have $37.2$ trillion cells.

Levels of Biological Organization

Cells - tissues - Organs - Organ systems - Organisms - Populations - Community - Ecosystem - Biome - Biosphere

Organelles

Specialized structures that perform certain tasks within the cell.

Zacharias Janssen

Produced the first compound microscope in the $1590's$ which initially magnified objects $9\times-10\times$.

Robert Hooke

English physicist who observed a slice of cork from an Oak tree and coined the name "cell" in $1665$.

Micrographia

The book published by Robert Hooke in $1665$ describing his observations using a compound microscope.

Anton Van Leeuwenhoek

Dutch Scientist known as the "father of Microbiology" who was the first to see living microorganisms using a powerful single-lens microscope.

Animalcules

The term used by Anton Van Leeuwenhoek for the living microorganisms he discovered, such as bacteria, protozoa, and sperm cells.

Matthias Schleiden

Botanist who published "Contributions to phytogenesis" in $1838$ and proposed that all plants are made up of cells.

Theodor Schwann

Scientist who published work on animal tissue in $1839$ and proposed that animal structures are made of cells.

Rudolf Virchow

Scientist who studied healthy and diseased tissues in $1855$ and popularized the idea that new cells come from pre-existing cells.

Omnis cellula e cellula

A Latin phrase introduced by Rudolf Virchow meaning "every cell come from a cell."

Spontaneous generation

The rejected theory that living things or cells form from non-living things.

Robert Remak

The first scientist to provide evidence that new cells arise from the division of existing cells, based on his $1852$ observations of animal embryos.

Francesco Redi

Scientist whose $1668$ experiment with meat and jars first challenged spontaneous generation by showing maggots come from flies.

Louis Pasteur

French scientist who definitively refuted the theory of spontaneous generation using his Swan-neck Flask experiment.

The Three Postulates of the Cell Theory

$1$. All organism are made up of cells; $2$. The cell is the basic structural and functional unit of life; $3$. All cells arise from pre-existing cell.

Modern Interpretation: Organism Activity

The activity of an organism depends on the activity of each individual, independent cell.

Modern Interpretation: Species Consistency

The genetic make up of the cell of the organism that belong to the same species is the same.