Questions and Answers
What is a cell?
The smallest functional unit of life
Who was Robert Hooke?
What significant discovery did Anton Van Leeuwenhoek make?
What did Henri Dutrochet conclude about cells?
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What did Robert Brown discover?
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What was Matthias Schleiden's contribution to cell theory?
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What did Theodore Schwann contribute to cell theory?
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What principle did Rudolf Virchow assert?
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Define spontaneous generation.
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Match the scientist with their contribution to disproving spontaneous generation:
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What does cell theory state about organisms?
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What are modern amendments to the cell theory?
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What are some exceptions to cell theory?
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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.
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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.
