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Modern Biology Theories

I have read my text and I still do not totally understand the four theories that contribute to Modern Biology. I would appreciate if you could give me a brief outline of the theories, including the theorists, the dates, and the basic concepts of the theories.

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Theories Contributing to Modern Biology

Modern biology is based on several great ideas, or theories:
1. The Cell Theory
2. Gene Theory
3. Homeostasis
4. The Theory of Evolution by Natural Selection

The Cell Theory

Robert Hooke (1635-1703), one of the first scientists to use a microscope to examine pond water, cork and other things, referred to the cavities he saw in cork as "cells", Latin for chambers. Mattias Schleiden (in 1838) concluded all plant tissues consisted of cells. In 1839, Theodore Schwann came to a similar conclusion for animal tissues. Rudolf Virchow, in 1858, combined the two ideas and added that all cells come from pre-existing cells, formulating the Cell Theory. Thus there is a chain-of-existence extending from your cells back to the earliest cells, over 3.5 billion years ago. The cell theory states that all organisms are composed of one or more cells, and that those cells have arisen from pre-existing cells.

Gene Theory

James Watson (L) and Francis Crick (R), and the model they built of the structure of DNA. In 1953, James Watson and Francis Crick developed the model for deoxyribonucleic acid (DNA), a chemical that had (then) recently been deduced to be the physical carrier of inheritance. Crick hypothesized the mechanism for DNA replication and further linked DNA to proteins, an idea since referred to as the central dogma. Information from DNA "language" ...

Solution Summary

This solution explains the four theories that contribute to Modern Biology (e.g. The Cell Theory, Gene Theory, Homeostasis, and the Theory of Evolution by Natural Selection). Specifically, it briefly outlines the theories, including the theorists, the dates, and the basic concepts of the theories.

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