TAMU BIOL 111 FLETCHER FINAL EXAM WITH VERIFIED SOLUTIONS ALREADY GRADED A+

describe the basic functions all life forms must accomplish -response to environmental stimuli & maintain homeostasis -uptake and processing of nutrients/energy -regulation -growth and reproduction compare and contrast eukaryotic and prokaryotic cell types Prokaryotes: -circular chromosomes, no nucleus, no organelles, 3.5 bya -DNA concentrated in nucleoid Eukaryotes: -linear chromosomes, nucleus, organelles, 1.5 bya -DNA concentrated in nucleus Both: -cellular function takes place in cytoplasm -have plasma membrane & cell wall (optional in eukaryotes) Brainpower Read More Previous Play Next Rewind 10 seconds Move forward 10 seconds Unmute 0:00 / 0:00 Full screen explain the importance of designing controlled experiments cancels the effects of unwanted variables describe the levels of biological organization from cell to biome atom -> molecule -> organelle -> cell -> tissue -> organ -> organ system -> organism -> population -> community -> ecosystem -> biosphere compare/contrast discovery science and hypothesis-driven science Discovery Science: -Describes natural structure & processes -Uses inductive reasoning (specific to general) Hypothesis-driven science: -Inquiry that asks a specific question -Uses deductive reasoning (general to specific) - If...Then... compare/contrast the concepts of hypothesis and scientific theory Hypothesis: -Tentative answer to a well framed question -Must be testable -Must be falsifiable -Can never be proven, only supported or refuted Theory: -A tested and confirmed explanation for observations of phenomenon -Broad in scope -Generates new hypotheses -Supported by a large body of evidence -Constantly being challenged, tested, and modified as new information is obtained explain the 2 main point of darwins "on the origin of species" 1) Descent with modification: Genetics 2) Natural selection: Ecology draw a diagram of an atom and label the parts Nucleus: Positively charged protons, no charge neutrons Electron Cloud: Negatively charged electrons explain how the structure of atoms changes as you move through the periodic table -As the atomic number increases so does mass, number of protons, -Moving down the periodic table adds a valence shell -Moving right adds valence electrons explain how isotopes differ from each other and how they can be used in biology -Isotopes of a given element differ in the number of neutrons in the nucleus, but have the same number of protons -Isotopes can be used in biology as a research tool (Ex: over time carbon-14 decays to nitrogen-14, and researchers compare the amount of carbon-14 in the atmosphere to the amount in fossil remain to determine the age of fossils) describe the relationship between electronegativity and chemical bonds -The stronger an atom attracts electrons in its bonds, the stronger its electronegativity and vise-versa compare and contrast ionic and covalent bonds -Covalent: share electrons, weak bond -Ionic: take electrons, very strong bonds -Both: involve valence electrons, form chemical bonds compare and contrast nonpolar and polar covalent bonds -Nonpolar: atoms have similar electronegativities, share electrons equally -Polar: atoms have unequal electronegativities, share electrons unequally -Both bond type and molecule shape determine polarity explain the importance of weak bonds/interactions for biology -Weak bonds allow for dynamic and easily reversible interactions -Reinforce the shapes of large molecules -Helps molecules reversibly adhere to each other predict the outcome of altering components of a reaction that was in chemical equilibrium -The concentrations of both reactants and products undergo additional changes after altering to return back to equillibrium explain how hydrogen bonds affect the structure and behavior of water -Bonds result from the polarity of water molecules -There is no net charge to a water molecule (slight positive on hydrogen, slight negative on oxygen) -Bonds constantly form/break as the molecules move past one another define hydrophobic and hydrophilic -Hydrophobic: do not mix with H2O(non-polar) -Hydrophilic: mixes with H2O (polar) calculate quantities/concentration of molecules and atoms (solution concentrations, pH, convert units) -Solution concentrations: molarity(M)=mol/L Steps 1) Calculate the molecular weight of your molecule 2) Calculate the number of grams needed to get the requested number of moles per L 3) Calculate the number of grams needed to get the requested molarity in the final volume -pH=potential hydrogen, low in acid (more H+ ions), high in base (more OH- ions), each pH unit represents a 10x difference in H+ concentrations, always adds to 14 -converting unit, use conversion factors and dimensional analysis define acid, base, weak acid, and weak base -Acid: any substance that increases the hydrogen ion concentration of a solution -Base: any substance that reduces the hydrogen ion concentration of a solution -Strong acid/base: dissociate completely in water -Weak acid/base: the binding and release of hydrogen ions is reversible explain how buffers work -Buffers are substances that minimize changes in concentrations of H+ and OH- in a solution -Consists of weak acid-base pair that reversibly combines with hydrogen ions (accepts/donates H+ ions to/from solutions depending on acid or base) explain why carbon is important for life -The key component of macromolecules -Can form covalent bonds with up to 4 different atoms -Makes possible the great diversity of organic molecules -Carbon is fixed form the atmosphere by photosynthesis - compare and contrast structural isomers, cis/trans (geometric isomers) and stereoisomers -Structural isomer: Differ in covalent arrangement of bonds -Geometric isomer: Differ in spatial arrangement around double bonds, trans (configuration where carbons are on opposite sides of double bonds), cis (configuration were carbons are on same side of double bonds) -Stereoisomers (Enantiomers): Have 4 different groups bonded to an asymmetric carbon, cannot superimpose (mirror images) identify common functional groups in a compound 1) Methyl: -CH3, unreactive but important in shape of many organic molecules 2) Hydroxyl: -OH 3) Sulfhydryl: -SH 4) Carbonyl: >C=O 5) Carboxyl: -COOH 6) Amino: -NH2 7) Phosphate: -OPO3^2- explain how the structure of a carboxyl group allows it to function as an acid The covalent bond between oxygen and hydrogen is so polar that hydrogen ions tend to dissociate reversibly name the 4 macromolecules of life -Carbohydrates -Proteins -Nucleic Acids -Lipids describe the difference between polymers and monomers and which macromolecules are classified as polymers -Polymer: Built from monomers, built from covalent bonds -Monomer: Individual subsets/building blocks, specific sets for each class, 40-50 common monomers -Macromolecules classified as polymers are carbohydrates, nucleic acids, and protein, lipids are not technically polymers