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| | Encyclopedia :: encyclopedia : Biology (Site not responding. Last check: ) |
 | | Nevertheless, the biological sciences are characterized and unified by several major underlying principles and concepts: universality, evolution, diversity, continuity, homeostasis, and interactions. |
 | | The most salient example of biological universality is that all living things share a common carbon-based biochemistry and in particular pass on their characteristics via genetic material, which is based on nucleic acids such as DNA and which uses a common genetic code with only minor variations. |
 | | The first group consists of those disciplines that study the basic structures of living systems: cells, genes etc.; the second group considers the operation of these structures at the level of tissues, organs, and bodies; the third group considers organisms and their histories; the final constellation of disciplines focuses on their interactions. |
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