Lecture 2I. Why isn’t a viruses the smallest unit of life?A. Virus might have genetic information that is enclosed however they lack necessary components to make them units of life1. they can not reproduce on their own2. they must infect other cells to live and reproduceII. Spontaneous GenerationA. Redi1. Though that maggots probably came from other flies2. worked woth eukaryotes3. Experimentsi. had 3 jars that all had mean in them a. a jar with no lidb. a jar with guaze over the coverc. a jar that was sealed with a lid4. Conclusioni. Maggots come from flies that lay their eggs on the meatB. Pasteur1. Preformed further experiements to disprove the idea of spontaneous generation2. Experiementi. worked with swan neck flask that contain non-sertile broth that was heated and sterilzedii. over time dust and microgranisms gathered at the bend in th enck of the flask and the liquid remained sterile over timeiii. tilited the flask so it made contact with the microgranims in the bend of the flask and over time the liquid was no longer sterile and microorganism grew in the liquid3. Conclusioni. spontaneous generation doesn’t occur air paricles and bacteria lead to the growth in the brothIII. Types of CellsA. Eukaryotic Cells1 . Contain a nucleus2. Plant and Animal Cells3. Membrane bound nucleus where the genetic information of the cell is housedB. Prokaryotic Cells1. Do not contain a nucleus2. very small3. Bactera and Archea CellsIV. Theory of Natural Selection (Charles Darwin)A. Scientist Darwin and Wallace proposed the idea that all living species had one common ancestor1. There is diversity among species because of evolution that has occurred over time giving species the diversity that it has todayi. This supports the idea that populations evolve over time and not individuals B . Conditions Necessary for Natural Selection to occur1. their must be a differentiable inheritable traits among individuals in a population 2. the trait that these individuals possess must enhance their survival or reproduction rates/opportunityi. traits that will become more common among the population* the cell theory and natural selection are ways that diversification among species have occurred and it implies that all organism stem from a common ancestor on the tree of life*V. Tree of LifeA. Three Domains 1. Bacteriai. Most of lifes diversity and so most of its deep evlotionary is microbialii. single cellediii. lacks membranes2. ArcheaI. closely related to Eukaryotesii. Lack membrane organellesiii. Extremeophilesa .Halophilesb. Acidophilesc. Thermophiles3. Eukarayai. plants ii. animalsiii. protistsiv. fungiv. can be single celled vi. Membrane bound organelles * Species that are closely related(close on the tree of life) they will have rRNA sequences that are more similar then those of species that are more distantly related  small units of rRNA sequences can be used to generate a phylogenetic(group) tree that will show evolutionary relationshipsB. Ribosomal RNA1. used in gene sequencing is used to establish evolutionary relationships among organisms i. Possible because organism with similar rRNA sequencing share a common ancestor2. the greater the variation in rRNA sequencing the less common ancestors there are between the organismC. Node- represents the common ancestor of all organisms that are aliveD. Archaea and bacteria have similar cellular organization evenhough archaea and eukaryotes are more closely relatedE. Eukaryotes and Archaea are closely relatedbecause their molecular machines function in similar ways1. specifically DNA replication2 Transcription3. Translation VI. How Scientist Think abut QuestionsA. Fact-an obersvation that has be repeatedly confrimedB. Hypothesis- a testable statement that can be used to builb more complex explanationsC. Law-a descriptive generalization; does not explain why something happens just describes itD. Theory – and overarching explanation that is well sustained and has withstood several experimentsVII. Scientific MethodA. Make ObservationsB. Form Hypothese1. null hypothesisC. Make PredictionsD. ExperimentE. Revise Hypothesis if NecessaryF. Perform more experiements and if they support hypoetstes it becomes a theory * Hypotheses and theoris can be supported or falsified based on data obtained fromexperimental prelication but it can never be provenVIII. Chemistry ReviewA. Basic Atomic Structure 1. Composition of Atomsi. Protonsa. postiviley charged particlesii. Neutronsa. neutral particlesiii. ElectronsA. negatively charged particles2. Protons and neutrons compose the nucleus3. Electrons can be found in surrounding orbitaksi. regions within the atom where electrons are more then likely to befoundB. Peridoic Tables1. Atomic Numberi. number of protons that is chacteristc of each element2. Elementi. atoms with the same atomic number that have the same chemicalproperties3. Isotopesi. forms of elements with different number of neutrons4. mass numberi. the number of protons and and neutrons of the most commonisotopeC. Electron Arranagement around the Nucleus1. Electrons move around atomic nuclei in regions known as orbitalsi. each orbital can hold up two electrons2. Orbitals are grouped into levels called electron shellsi. electron shells are numberedii. the electrons in the outmost cells are valence elctrons3. elements commonly founf in orgainism habe at least one unpaired valenceelectronsi. the number of unpaired electrons in an atom is its