2 Science Methods Steps used to solve a problem Observation Questioning and stating problemsHypothesizingExperimenting – including a control and experimental groupIV – independent variable—the condition that is changed by the scientistDV – dependent variable—what is measured or observed during an experimentTables and GraphsIV on x-axis andDV on y-axis of a graphEx) Effects of pH on Tadpole SurvivalIV – pHDV-Number of TadpolesScenario:John’s lab group compared the effect of different-aged grass compost on bean plants. The group hypothesized that older grass compost would produce taller bean plants. Three flats of bean plants (25 plants/flat) were grown for 5 days. The plants were then fertilized as follows: Flat A: 450 g of 3-month old compost, Flat B: 450 g of 6-month old compost, and Flat C: 0 g of compost. The plants received the same amount of sunlight and water each day. At the end of 30 days, the group recorded the height of the plants (cm).Independent Variable –Dependent Variable –Control Group –Constants –
3 Characteristics of Life All living things exhibit several basic life characteristics:Cellular organization*unicellular – one celled (Example: Eubacteria, Archaebacteria, Protist)* multicellular – many celled with levels oforganization (cellstissuesorgans systems organism)Reproduction*asexual – offspring are genetic clones of parent (Ex: Binary Fission)*sexual – offspring have genetic variation from parentsMetabolism* energy is required for life processes* autotrophs make their own food (photosynthesis/chemosynthesis)* heterotrophs eat other organisms for food (cellular respiration)Examples: Herbivores, Omnivores, Carnivores, DecomposersHomeostasis* maintenance or regulation of body conditions such as body temperature, blood sugar level, water balance (Ex: Humans sweat to lower body temperature)Heredity* DNA – deoxyribonucleic acid – is the genetic material that codes for proteins of all organisms. The genetic code is “universal”Response to stimuli* responding to the biotic (living) and abiotic (nonliving) factors in the environment are key to survival (Ex: birds fly south in the winter)Growth and Development* growth – increase in the amount of living matter either by cell division (mitosis) or cell enlargement* development – any change from conception to death - embryonic, puberty, agingEvolutionary Adaptation* adaptations – structures, behaviors, or processes that aid in an organisms survival are passed on from parent to offspring. (Survival of the Fittest)
4 ChemistryOrganisms are composed of organic compounds – carbon containing compounds that can be very large macromolecules (Atom ---> molecule --- compound macromolecule)Each macromolecule starts with a monomer & uses them to build a polymerFour main types:Carbohydrates – composed of monosaccharides primarilyglucose(monomer) that builds Disaccharides & Polysaccharides, functionas main energy source and build cell wall of plants2. Lipids – composed of fatty acids joined to glycerol (monomers), may contain phosphate group to form a phospholipid, includes fats & steroids - functions as stored energy, insulation, waterproofing, & builds cell membranes3. Proteins – composed of long chains of amino acids (monomer - 20 different types) called a polypeptide – functions include structural components, enzymes, antibodies 4. Nucleic acids – are composed of nucleotides (monomers) either DNA or RNAMetabolism is the chemistry of life – all metabolism is controlled by the action of enzymesEnzymes are proteins that function to speed up chemical reactions in the cell. They have a specific 3D shape and interact with a specific substrate which binds at the active site. Enzymes are reusable and are notChanged during a chemical reaction.They can be denatured (permanentchange of the 3D shape) at extremetemperature and pH.Enzymes are catalyst – they speed upa reaction without being used up(reused over & over)
5 ChemistryCovalent Bonds - Formed when two atoms share one or more pairs of electronsIonic Bonds – chemical bond formed when atoms lose or gain electrons , atoms that lose electrons are called positive ions (cations), atoms that gain electrons are called negative ions (anions), Because positive and negative electrical charges attract each ionic bonds form Chemical reactions - The amount of energy needed to start the reaction is called activation energy - The net release of free energy during a reactions is called an exergonic (exothermic) reaction - a net absorption of free energy are called endergonic (endothermic) reactionsExothermic Endothermic Solute is the substance dissolved in the solution - particles may be ions, atoms, or moleculesSolvent is the substance in which the solute is dissolved - water is the universal solventDissociation of water - H2O H+ (hydrogen ion) + OH- (hydroxide ion)Acids = Number of hydrogen ions in solutions is greater than the number of hydroxide ionsBases = Number of hydroxide ions in solution is greater than the number of hydrogen ions
6 EcologyEcology – is the study of interactions between organisms and the environmentLevels of OrganizationBiosphereBiomesEcosystem CommunityPopulationOrganismWe study an organisms habitat (where they live), niche (their role in the habitat), and trophic level (their feeding level)Populations – are members of the same species living in the same place at the same time with the potential to interbreedPopulation growth – exponential (J-shape) and logistic (S-Shape)* Limited by factors like disease and competition that are density-dependent or by density-independent factors like natural disaster.* Carrying capacity is seen in logistic growth – the maximum number the environment can supportCommunity Interactions* Competition – intraspecific (same species) or interspecific (diff sp)* Symbiosis –*parasitism --One benefits & the other is harmed*commensalism--One species benefits, the other is unaffected*mutualism--Both species benefit* Succession – both primary (bare rock) and secondary (soil)Ecosystem Level – food chains and webs and matter recycling
7 Cells Cell theory - 3 parts 1) cells are basic unit of life 2) cells come from existing cells3) all organisms are composed of cellsProkaryotic versus EukaryoticA) simple-unicellular A) complex (uni- or multicellular)B) has no nucleus B) has a MB nucleusC) has no MB organelles C) has MB organellesD) includes bacteria D) includes protists, fungi, plants, and animalsOrganelles – compartments for carrying out specific jobs / chemical reactions1) chloroplast – photosynthesis 7) lysosome--digestion2) mitochondria – cellular respiration 8) Endoplasmic Reticulum-(smooth3) ribosomes – protein synthesis rough); Transports lipids and4)vacuoles-storage proteins5) nucleus – contains DNA and 9) golgi bodies-modifies and controls cell actions packages proteins for export6) nucleolus – site of ribosome formationPlant versus AnimalA) has cell wall A) no cell wallB) has chloroplasts/plastids B) has no plastids/chloroplastsC) has large vacuole C) has small vacuolesD) no centrioles D) hasCentrioles
8 Cellular Transport Plasma membrane controls homeostasis (balance) Structure – composed of a phospholipid bilayer withembedded proteins “gates”Function – acts as a selectively permeable boundaryaround the cellTypes of Passive Transport – no energy required1) Diffusion – moves substances from high to low concentrations down their concentration gradient2) Osmosis – the diffusion of water from high to lower water concentrations down its concentration gradientEx) cell in salt water – shrivels Ex) cell in fresh water swells3) Facilitated diffusion – movement of a substance down its concentration through a transport protein channelActive Transport – requires energy – moves substances against the concentration gradient from low to high concentrations
9 PhotosynthesisThe process used by producers to convert sunlight to chemical energy in glucoseOverall equation: 6CO2 + 6H2O C6H12O O2Occurs in the palisade layer of leaves (yellow layer under the upper epidermis) in meosphyll cellsLarge numbers of chloroplasts are found in these mesophyll cells.Chloroplasts are the cellular site of photosynthesis. The light reaction of photosynthesis occurs on the inner membrane called the thylakoid. The dark reaction (aka Calvin Cycle) occurs in the stromaGas exchange takes place through stomataPigments absorb light energyChlorophyll, Carotenoids, Tannins, Anthocyanins, XanthophyllsInput(Reactant)Output (Product)Light reaction(Light-Dependent)LightWaterOxygenATPNADPHDark Reaction(Light-Independent, AKA Calvin Cycle)ATP, Carbon Dioxide, NADPHGlucose
10 Overall equation: C6H12O6 + 6O2 6CO2 + 6H2O + 38 ATP Cellular RespirationCellular respiration is the process by which organisms break down food to release its energy. This energy is then stored in ATP (Adenosine triphosphate)Three parts to ATP1) adenine (Nitrogenous base)2) ribose (5-Carbon sugar)3) 3 phosphates (high energy)ATP/ADP cycle – when energy is needed for cell work, ATP loses a phosphate to become ADP—when energy is strored ADP adds phosphate to become ATP againOverall equation: C6H12O O2 6CO2 + 6H2O + 38 ATPRespiration can be aerobic or anaerobicAerobic AnaerobicO2 required no O2 requiredmost organisms are aerobes few anaerobes (yeast/bacteria)38 ATP produced ATP produced (much less!)3 steps – glycolysis, Krebs cycle, steps – glycolysis and electron transport fermentation (alcoholic and lactic acid)Glycolysis is the first step of both anaerobic and aerobic, and glycolysis occurs in the cytoplasm of the cellIf no oxygen is present after glycolysis (anaerobic), then fermentation occursIf oxygen is present after glycolysis (aerobic), then the Krebs cycle and electron transport chain will occur in the mitochondria (produces most of the ATP)
11 DNA, RNA, and Protein Synthesis DNA and RNA are composed of nucleotidesDNA RNADeoxyribose Sugar Ribose SugarA, C, G , Thymine A, C, G, UracilDouble helix Single helixCodes for proteins/RNA Copy of DNA infoReplication – the process used by cells to copy DNA – enzyme unzips DNA and each side of the ladder acts as a template for the building of the new half. Use the N-base paring rules : A-T ; C-GEX) TACGGAC (old strand)ATGCCTG (new strand)Transcription – the process of making RNA from DNAEX) TACGGAC (template DNA strand)AUGCCUG (RNA built)3 Types of RNA have a role in protein synthesis1) mRNA – messenger-blueprint for how to build a protein2) tRNA – transfer - carries amino acids to ribosome3) rRNA – ribosomal – makes up a ribosomeTranslation – the process ofof building a protein by matchingCodons in mRNA to anticodonsof tRNA (use codon chart)Purine(A & G)Pyrimidine(T, U & C)
12 Reproduction Reproduction is a fundamental characteristic of life Propagates your species2 form: asexual and sexualAsexual Sexual____________-1 parent parents (usually)-No gametes Fusion of gametes-Offspring are genetically identical Offspring genetically uniqueto the parent (clones)-Fast, efficient, less energy Slower, less efficient, more energy-No variation Huge amounts of variation-Stable Environment Changing EnvironmentAsexual Strategies1) binary fission2) budding3) fragmentation/fissionSexual strategies1) Internal fertilizationCopulation (vagina/penis) –sperm meets egg in female2) External fertilizationSpawning – eggs and spermreleased into the environmentusually aquaticIn humans fertilization occursin the fallopian tube.
13 Cell DivisionHaploid – having one set of chromosomes (n) – gametes – sperm/eggDiploid – having two sets of chromosomes (2n) – body cells – one set is maternal and one is paternalThe cell cycle – Interphase – growth, Mitosis – division of nuclear material and Cytokinesis-division of cytoplasmMitosis creates diploid cells and is for the purpose of tissue repair and growth in animalsDNA coils to form chromosomes during cell divisionStages of the cell cycle (see diagram)Interphase, Prophase, Metaphase,Anaphase, Telophase, CytokinesisMeiosis – cell division that creates 4 haploidcells called gametes – aka – reduction divisionMeiosis involves 2 divisions – Meiosis Iand Meiosis IIMeiosis I has some special events:In Prophase I homologous chromosomespair up and crossing over occurs. Thisrecombination increases geneticvariation for the speciesMetaphase I – Homologous Pairs line upAnaphase I – Homologous pairs are separatedMeiosis II is similar to mitosisAnaphase II—sister chromatids separate
14 Note 9:3:3:1 phenotypic ratio Simple GeneticsGregor Mendel worked with pea plants to learn the basic patterns of inheritance.Phenotype – what the organism looks likeGenotype – the gene combination – either Homozygous (TT or tt)or Heterozygous (Tt)Allele-2 versions of a gene (dominant or recessive)Monohybrid Cross – follows 1 trait through several generationsP(parental) TT x ttT T T tt geno- all Tt T geno – ¼ TT, ½ Tt, ¼ ttt pheno – all tall t pheno – ¾ Tall; ¼ short(3:1 ratio)Other important monohybrid crossesT t T tT geno- ½ TT; ½ Tt t geno – ½ Tt; ½ ttT pheno – all Tall t pheno– Tall; ½ shortDihybrid cross – follows two traits—FOIL method to find gametesTtTTTtttTtTtttNote 9:3:3:1 phenotypic ratio
15 Complex Genetics R R R r r geno- all Rr r geno- ¼ RR; ½ Rr; ¼rr Incomplete Dominance – intermediate/blended phenotype (you see a mix)Ex) snap dragons Red (RR) X White (rr) all PinkR R R rr geno- all Rr r geno- ¼ RR; ½ Rr; ¼rrr pheno-all pink r pheno- ¼red; ½ pink; ¼ whiteCodominance – both parental phenotypes show up in offspringEx) Chickens Black x White Black and White feathersMultiple Allelism/Codominance – trait with 3+ allelesex) A, B, O blood typesSex Linkage (sex-linked)– genes carried on sex chromosomesEx) hemophilia, color blindness Cross shows acarrier female and a normal male. For a female toinherit the trait the father must have it and themother must at least be a carrierPolygenic Inheritance – traits controlledby many genes Ex) Height, hair colorAneuploidy – condition caused byhaving abnormal chromosome number.Ex) Down’s Syndrome aka Trisomy 21Monosomy-only 1 chromosomeTrisomy-three chromosomesPolysomy-4 or more chromosomesRrRRRrrr
16 DNA Technology Today, DNA techniques include: 1) DNA Extraction – the opening of cells to separate/isolate DNA from other cell parts2) Cutting DNA – large DNA molecules are cut into smaller fragments using restriction enzymes. These enzymes recognize and cut DNA at specific sequences.3) Separating DNA – DNA fragments can be separated and analyzed using gel electrophoresis. This process allows scientists to compare genomes of different organisms, separate genes, and create DNA “fingerprints”4) Sequencing DNA – this process allows scientists to determine the sequence of N-bases in DNA.5) Recombinant DNA – scientists can cut DNA from two sources with the same restriction enzyme and combine them. This is used in genetic engineering. This process has been used to create human proteins used to treat disease, create pest-resistant crops, and for many other purposes.6) Copying DNA – polymerase chain reaction (PCR) has been developed that makes many copies of a small amount of DNA.
17 EvolutionCharles Darwin – proposed that organisms (species or populations) change over timeOccurs by Natural Selection – “survival of the fittest”Lines of evidence1) fossils (geologic time)2) Homologous Structures –same basic structure formed fromsame embryonic tissue3) Analogous Structures – samebasic functions due to sameenvironmental pressures4) Vestigial Structures – structuresthat have lost function ex) appendix5) Embryology – embryos of variousspecies appear identical6) Biochemistry – DNA and protein amino acid sequence comparisonsAdaptive radiation – an ancestralspecies radiates or diverges into manyspecies. Ex) Galapagos FinchesOrigin IdeasEndosymbiont theory – eukaryotic cells formed when prokaryotic cells beganto live together permanently ; Shown in diagram below (theory that explains why mitochondria has DNA)Speciation- formation of new species caused because of: reproduction isolation, behavioral isolation, geographic isolation, temporal isolationHomologousVestigial
18 ClassificationCarolus Linnaeus – developed 7 categories of classificationAlso developed binomial nomenclature – naming using the genus and species names to refer to an organism – named in LatinExample: Humans: Homo sapiens or Homo sapiens (First word [genus] is capitalized, Second word [species] is not). Scientific names should either be underlined or italicizedClassification tools include dichotomous keys – a series of paired statements that lead to the name of an organism1a) Object has no sides Go to 21b) Object has sides Go to 32a) Object is oblong oval2b) Object is symmetrical circle3a) Object has 3 sides triangle3b) Object has 4 sides Go to 44a) Object has 4 equal sides square4b) Object doesn’t have 4 equal sides . . rectangle
19 Kingdoms http://www.ric.edu/ptiskus/Six_Kingdoms/Index.htm How are organism placed into their kingdoms?1) Cell type, complex or simple2) Their ability to make food3) The number of cells in their bodyFive Kingdom SystemMonera – all prokaryotic includes the bacteriaProtista – most are unicellular, eukaryotic, and aquaticFungi – all eukaryotic heterotrophs that act as decomposersPlantae – all eukaryotic autotrophsAnimalia – all eukaryotic heterotrophs that must eat other organisms for foodIn Six Kingdom system the Kingdom Monera has been divided into the Archaebacteria and the EubacteriaArchaebacteria – are extremists that live in hot, acidic, saline, or other harsh environmentsEubacteria are “true” bacteria that come in 3 shapes1) round (coccus)—like grapes2) rod (bacillus)3) spiral (spirillus)
20 Plants Plant cell structure – cell walls, large vacuole, chloroplasts PhotosynthesisClassification – 4 groups1) Nonvascular – no true roots/stems/leaves – ex) mosses (Bryophytes)2) Seedless vascular plants – Ferns3) Vascular with seeds in cones – Gymnosperms (pines, fir, spruce)4) Vascular with seeds in fruits – Angiosperms – flowering plantsTypes of Vascular TissueA) Xylem – transports water from roots to leavesB) Phloem – transports sugars from leaves to rootsReproductive Life Cycle – called Alternation of Generations (haploid to diploid)Self-Pollination—plant pollinates itselfCross Pollination—one plant pollinates another plantTropism-- growth responses to stimuli
21 Animals Usually reproduce by sexual reproduction Animal cell structure – no cell wall, small vacuoles, no plastids, centriolesClassification – 2 main groupsVertebrates InvertebratesPhylum Chordata 9 Phyla3 classes of fish Arthropods – insects (6 legs)Amphibians (exoskeleton) - arachnids (8 legs)Reptiles crustaceansAves (birds) Mollusks – have shell created byMammals structure called mantelHuman Anatomy – Look through the chapters in your book regarding anatomy.* Neurons* Heart* KidneysAnimal Behavior – responses that allow an organism to respond to stimuli1) Innate Behavior – instincts, inherited, inborn behaviorsex) circadian rhythms – daily patterns of activity – including feeding behaviors - nocturnalex) annual rhythms – yearly patterns of activity – including courtship, estivation, hibernation, migration2) Learned Behavior – based on experienceex) imprinting – recognition of parentsex) Trial and error learningex) Conditioning (Pavlov’s dog) – learning by association3) Social Behavior – division of labor as in a termite or ant colony
22 BiologistsRobert Hooke – discovered and named the cell with crude microscopeAnton van Leeuwenhoek - saw “wee little beasties” living cells for the first timeGregor Mendel – is the father of genetics – discovered the basic patterns of inheritance in pea plantsCharles Darwin – is the father of evolution theory – proposed that organisms that are most fit or best adapted to their environment are more likely to survive – called Natural SelectionJames Watson and Francis Crick – discovered the double helix structure of DNA by examining an x-ray made by Rosalind Franklin and Maurice WilkinsLouis Pasteur – helped disprove abiogenesis or spontaneous generation by creating a s-neck flask and showing that microorganisms spoil foodSpallanzani – discovered that nutrient solutions helped grow microorganisms and experimental study of bodily functions and animal reproductionKettlewell– studied evolution of peppered moth; Moths were originally light-colored for camouflage purposes (increased their survival). After the Industrial Revolution, trees were darkened, so the fittest moths for survival were the dark colored (natural selection)Redi – best known for work with maggots to disprove spontaneous generation—he challanged Needham’s workNeedham – botonist who experimented to provide proof of spontaneous generationLamarck – evolutionist—theory of acquired characteristics—organisms acquired whatever was needed to survive in the environment (Ex: giraffe neck)
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