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Unformatted text preview: LS2 Chapter 1: Studying Life 1.1 What is biology? A. Biology is the scientific study of living things B. All living things diversified from the same ancestor 4 billion years ago C. Most living things 1. Consist of one or more cells 2. Contain genetic information 3. Use genetic information to reproduce themselves 4. Are genetically related and have evolved 5. Can convert molecules obtained in from the environment into new biological molecules 6. Can extract energy from the environment and use it to do biological work 7. Can regulate their internal environment D. Living organisms consist of cells 1. Cell theory a. Cells are the basic structural and physiological units of all life b. Cells are both distinct entities and building blocks of more complex organisms c. All cells come from preexisting cells d. All cells are similar in composition e. Complete sets of genetic information are replicated and passed on during cell division 2. Spontaneous generation: the idea that life emerges from non-life E. The diversity of life is due to evolution by natural selection 1. Species: a group of organisms that are morphologically similar and can breed successfully 2. Adaptation: Structural, physiological, or behavioral trains that enhance and organisms chance of survival 3. Natural selection: any trait that increases an organisms' ability to reproduce would be favored and increase in the population F. Biological information is contained in a genetic language common to all organisms 1. Genome: sum total of all DNA molecules in the cell 2. DNA: molecules made of long sequences of four subunits called nucleotides 3. Genes: specific segments of DNA which contain the information cells use to make proteins 4. Proteins make up much of an organisms structure and are the molecules that govern the chemical reactions within cells 5. All cells of a multicellular organisms contain the same genome, yet cells have different structures and have different functions 6. Therefore, different types of cells must express different parts of their genome 7. Alteration of genes is called mutation 8. Mutations are spontaneous and can be caused by outside factors 9. Sometimes, a mutation can improve the function of an organism G. Cells use nutrients to supply energy and to build new structures 1. Cells take in nutrient molecules and break them into smaller chemical units 2. Breaking bonds releases energy that can be used for work (mechanical/ synthesis) H. Living organisms control their internal environment 1. Organisms made of more than one cell have an internal environment that is not cellular 2. The cells are bathed in extracellular liquids from which they receive nutrients and excrete wastes 3. Assemblies of similar cells are organized into tissue....
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- Spring '08