Bio 172 Exam 1 Flashcards Portage learning

Anton van Leeuwenhoek -first to view single-celled "animalcules" in pond water -Shows paramecium, and also looked at human blood and sperm cells Theodor Schwann -organisms are composed of cells Rudolf Virchow -cells come from preexisting cells Cell Theory -All organisms are composed of cells (cells are the structural unit of life) -Cells are the functional unit of life •cells are the smallest entities that have all the properties of life •each cell is (or can potentially generate) an entire organism -all cells are fundamentally similar •structure and organization •metabolic strategies •hereditary information -all cells come from pre-existing cells Francesco Redi -disproved spontaneous generation with the rotting meat and maggots example phylogeny -the evolutionary relationship between cells can be determined comparing genetic information Thermophiles -many thrive at 90˚C, a few at 110˚C Halophiles -happy in high salt environment acidophiles thrive at pH 2.0 fact -an observation that has been repeatedly confirmed hypothesis -a testable statement that can be used to build more complex explanations law -a descriptive generalization; does not explain why something happens-just describes it theory -an overarching explanation that is well-substantiated and that can incorporate facts, laws, inferences, and tested hypotheses covalent bond -when two atoms share pairs of valence electrons nonpolar covalent bond -electrons are shared equally polar covalent bonds -electrons not shared equally