Chapter 1 - CHAPTER1 Mostlivingorganisms...

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CHAPTER 1 Most living organisms - Consist of one or more cells - Contain genetic information - Use genetic information to reproduce themselves - Are genetically related and have evolved - Can convert molecules obtained from the environment and use it to do biological work - Can regulate their internal environment Cell theory - Cells are the basic structure and physiological units of all living organisms - Cells are both distinct entities and building blocks of more complex organisms - All cells come from preexisting cells - All cells are similar in chemical composition - Most of the chemical reactions of life occur within cells - Complete sets of genetic information are replicated and passed on during cell division Natural Selection - Leads to adaptations: structural, physiological, or behavioral traits that enhance an organism’s  chances of survival and reproduction in its environment. Biological information is contained in a genetic language common to all organisms - Genome: sum total of all the DNA molecules (long sequences of four difference subunits called  nucleotides) in the cell; genomes contain cell’s instructions or “blueprints”; all cells of a multi- cellular organism contain the same genome, but different cells have different functions and form  different structures, so different types of cells express different parts of their genome; genome  consists of thousands of genes  - The sequence of nucleotides contain genetic information - Genes: specific segments of DNA which contain the information the cell uses to make proteins; if  nucleotide sequence of a gene is altered, it’s likely that the protein that gene encodes will be  altered   “mutation” o Mutations: alternations of genes; occur spontaneously; a change in the properties of a protein  which alters its function in a beneficial way   raw material of evolution - Proteins: molecules that govern the chemical reactions within cells; proteins make up much of an  organism’s structure - Book analogy: nucleotides of DNA = letters in alphabet; protein molecules = sentences that they  spell; combinations of proteins that constitute structures and control biochemical processes =  paragraphs;   structures/processes   that   are   organized   into   diff   systems   w/   specific   tasks   (XX  digestion/transport) = chapters of the book; organism = complete book; natural selection = author/ editor of all books in the library of life Cells use nutrients to supply energy and to build new structure - Nutrients:   supply   living   organisms   with   energy   and   raw   materials   for   building   biological  structures; cells take in nutrient molecules + break them down to smaller chemical units  
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This note was uploaded on 08/10/2010 for the course BIS 2A BIS 2A taught by Professor Gerhart during the Spring '10 term at UC Davis.

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Chapter 1 - CHAPTER1 Mostlivingorganisms...

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