Cell Theory Timeline Flashcards

Study Notes

Cell Definition

Cells are the smallest functional unit of life, essential for all living organisms.

Robert Hooke

English scientist known for observing cork under a microscope and naming the structures he saw "cells," which were actually cell walls of dead tissue.

Anton Van Leeuwenhoek

Dutch scientist who discovered single-celled organisms in pond water using a high power simple microscope; also examined blood cells and sperm but did not pursue further studies.

Henri Dutrochet

French scientist who proposed that "the cell is the fundamental unit of organization." He conducted significant research on respiration and photosynthesis in plants and contributed to the understanding of osmosis.

Robert Brown

English scientist who discovered and named the nucleus, studied cytoplasmic streaming, and coined the term "Brownian motion" to describe the random movement of particles in a fluid.

Matthias Schleiden

German scientist who established that all plant tissues are composed of cells, forming a foundation of cell theory.

Theodore Schwann

German scientist who stated that all living things are made of cells and their products, co-authoring cell theory with Schleiden. He introduced the term "metabolism."

Rudolf Virchow

German scientist who famously stated that "cells come from preexisting cells," providing a counter to the theory of spontaneous generation.

Spontaneous Generation

An ancient belief that living organisms could arise from decaying organic matter, exemplified by the notion that aphids could emerge from dew on plants.

Experiments to Disprove Spontaneous Generation

Francesco Redi demonstrated that maggots do not arise from meat in sealed jars.
Louis Pasteur used pasteurization to show that microbes are not generated from broth, effectively debunking spontaneous generation.

Cell Theory

Composed of three main tenets:
- All organisms consist of one or more cells, which can be unicellular, multicellular, or colonial.
- The cell is the basic structural and organizational unit of life; metabolism occurs within cells, which share similar chemical activities.
- Cells arise from preexisting cells, supporting the idea that all life originated from a single cell evolving over millions of years.

Modern Amendments to Cell Theory

Energy flow and metabolism occur in all cells.
Cells contain hereditary information transmitted during cell division.

Exceptions to Cell Theory

Viruses are controversial; some consider them living, yet they are not made of cells.
The origin of the first cell remains an unanswered question.
The Miller-Urey experiment simulated early Earth conditions, showing that complex organic compounds could form from simple inorganic materials.

Description

Explore the key concepts and figures in cell theory with these flashcards. From the definition of a cell to the contributions of Robert Hooke and Anton Van Leeuwenhoek, test your knowledge on foundational ideas of biology. Perfect for students wanting to grasp the history of cellular biology.