General Biology: Characteristics of Life and Cell Theory

Flashcards reviewing the definitions of life, the characteristics of living organisms, the historical discovery of the microscope and cell, and both classical and modern cell theory postulates.

Biology

The science of life or living matter in all its forms and phenomena, derived from the Greek words "bios" (life) and "logos" (study). It deals with living organisms and vital processes ranging from unicellular creatures to human beings.

Metabolism

A chemical reaction that changes food molecules to energy, allowing living organisms to carry out life processes such as growth, reproduction, and environmental response.

Homeostasis

A state of equilibrium or balance maintained by living things, exemplified by temperature regulation such as sweating when internal temperature is high and shivering when it is low.

Zacharias Janssen (1580–1638)

Inventor who developed the first compound microscope in 1595 by placing lenses at each side of a tube to magnify objects.

Robert Hooke (1635–1703)

Scientist who built a microscope in 1665, examined a thin slice of cork, observed tiny compartments, and named them "Cellula" (which became known as cells).

Cellula

The term coined by Robert Hooke in 1665 to describe the tiny compartments observed in a thin slice of cork, which eventually became known as cells.

Anton van Leeuwenhoek (1652–1723)

Known as the Father of Bacteriology and Protozoology; in 1667 he created a microscope with much higher magnification and observed white blood cells, red blood cells, yeast cells, sperm cells, and bacteria cells.

Matthias Jakob Schleiden (1804–1881)

A botanist at the University of Jena, Germany, who proposed in 1838 that all parts of the plant organism are composed of cells.

Theodore Schwann (1810–1882)

A professor of physiology who stated in 1839 that all animal organisms are composed of cells.

Rudolf Ludwig Karl Virchow (1821–1902)

Scientist who recognized in 1858 that diseases in organs and tissues arise from affected cells and stated "Omnus cellula e cellula" (all cells come from pre-existing cells).

Omnus cellula e cellula

A Latin phrase stated by Rudolf Ludwig Karl Virchow meaning "all cells come from pre-existing cells."

Final Postulates of Cell Theory

The three classical postulates establishing that: (1) All organisms are made up of cells, (2) The cell is the basic unit of life, and (3) Cells arise from pre-existing cells.

Spontaneous Generation

The disproven concept that life comes from non-living matter, which is refuted by the cell theory postulate that cells arise only from pre-existing cells.

Hereditary Information (Modern Cell Theory)

Genetic information passed from cell to cell during cell division, ensuring each new cell is a genetic copy of its parent cell.

Chemical Composition of Cells (Modern Cell Theory)

The principle that all cells share the same basic chemical makeup at their core, containing water, inorganic ions, and carbon-containing molecules.

Energy Flow (Modern Cell Theory)

The principle stating that energy flow occurs within cells, meaning that all metabolic and biochemical processes take place inside cells.