Mrs. Stahl



The pictures were obtained from various websites. Most web addresses are below the pictures if you would like to use them or look at them. The Goal of Science: 1) deals only with the natural world2) to collect and organize information3) propose explanations that can be testedScience - using evidence to learn about the natural world; a body of knowledge Always begins with observations.Data- information gathered from observations.Quantitative- numbersQualitative- descriptiveThe Scientific Method:2054225topMake an ObservationAsk a QuestionHypothesisExperimentationAnalyze resultsConclusionRepeatIf you analyze your results and find that your hypothesis was incorrect or false, try again. Reconstruct / fix your hypothesis and start over!If your results are correct and your hypothesis is true, report your results and get published!!! Woohoooo Why is it important to replicate or duplicate your results?Instrumental errorPersonal errorSample size is too small or it isn’t a good mixInconsistency and inaccuracyExperimental design is flawed or messed up.Measurement errorHypothesis- prediction based on prior knowledge or a tentative explanation for an observation, phenomena, or scientific problem.Inference- logical interpretation based on prior knowledge. Theory- proposed explanation for a wide range of observations that has been supported by a wide range of observations. Ex- Theory of Evolution. Scientific law- Backed up by a large amount of proven research and has never been disproven. Example- Newton’s Laws of Motion Variable- things that may change in your experiment. Independent Variable- manipulated variable. This is what the experimenter has control over and can change. For example- time, amount of something like a chemical, amount of sunlight.Dependent Variable- the observed variable in an experiment. The data that is collected or the change caused because of the independent variable. For example- plant heightControlled Variable- Variables that remain the same. For example- same amount of water, same amount of sunlight, same size pot.Graphs- y-axis= Dependent Variable. x-axis = Independent VariableTypes of Microscopes Light Microscope - the models found in most schools, use compound lenses to magnify objects. The lenses bend or refract light to make the object beneath them appear closer. Common magnifications: 40x, 100x, 400xStereoscope - this microscope allows for binocular (two eyes) viewing of larger specimens. Scanning Electron Microscope - allow scientists to view a universe too small to be seen with a light microscope. SEMs do not use light waves; they use electrons (negatively charged electrical particles) to magnify objects up to two million times. Scans the surface and is too strong for living organisms.Transmission Electron Microscope - also uses electrons, but instead of scanning the surface (as with SEM's) electrons are passed through very thin specimens. This allows for a detailed internal look!Characteristics of all Living Things:Made up of cells- Unicellular- single or one celled= Prokaryotes like bacteriaMulticellular- many cells= Eukaryotes like Plants and AnimalsCells-> tissues-> organs-> organ systems-> organismReproduction- Asexual- one parent, offspring is genetically identical to the parent.Budding= HydraFragmentation= Sea starBinary Fission= BacteriaSexual- two parents, gametes (sperm and egg). Offspring are genetically different.Metabolism- chemical process that breaks down or builds up materials. Autotrophs- make their own food through photosynthesis and chemosynthesisHeterotrophs- eat other organisms. Cellular Respiration.Homeostasis- maintenance or regulation of internal body conditions. Body is at a balance- temperature, blood sugar levels, and water balance. DNA- deoxyribonucleic acid- the genetic material that codes for proteins of all organisms.Response to Stimuli- responding to factors in the environment. Abiotic- non-living such as water, sand, temperatureBiotic- Living such as plants and animals. Growth and Development- Growth- increase in the amount of living things through cell division or cell enlargement.Development- Changing from conception to death. Baby-> olderEvolution- Change over time. Adapting to survive- behaviors, structures, processes that increase its chances of survival that are passed on from parent to offspring. BiochemistryAtom- smallest basic unit of matter.Element- one particular type of atom that cannot be broken down into simpler substances. Ex- OxygenCompound- substance made up of atoms of different elements. Ex- H2O = water.Molecule- two or more atoms held together by covalent bonds. Protons- Positively charged particles. In the nucleus.Neutrons-Neutral / no charge. In the nucleus. If you are asked to find the PEN of an element:Atomic number equals the number of protons and electrons in a neutral atom. There are 6 protons and 6 electrons.Atomic Mass is the sum of protons and neutrons. Therefore if you know you have 6 protons there must be 6 neutrons because 6 + 6 =12Electrons-Negatively charged particles. In the electron cloud = outer rings. 2-8-8-18-32 when an atom gains or loses and electron.Ionic Bond- oppositely charged ions= opposites attract (+ / -). Ex- Na+Cl-. Outermost energy level needs to be full with the maximum number of electrons in that level in order to be stable. Bond- atoms share a pair of electrons. Strongest bond. Hydrogen Bonds: attraction between a slightly positive hydrogen and slightly negative oxygen. Weakest bond. Properties of Water:Properties of Water TableProperty of WaterExplanation of PropertyPhenomenon / ExamplesCohesionWater molecules stick togetherWater droplets on a car, drops of water on a pennyAdhesionWater molecules stick to other substances.Water sticking to the sides of a graduated cylinder.Surface TensionThe amount of force required to break the surface of the water.Spider walking in water or paper clips floating on the water.Capillary ActionWater molecules stick to tubes of small diameter.Plants transport water from roots to leaves. Also water going up a straw.High Specific HeatWater resists changes in temperature. Water has to absorb a lot of heat energy to increase temperature. Boiling or melting point. ** Solvent / Solute= the solvent is the substance that is present in the greatest amount and is the substance that dissolves the solutes. Solute is the substance that dissolves. Ex- Solvent = water and the solute= Kool-Aid packet. All organisms are made up of organic compounds / carbon based molecules / macromolecules.Polymer- many monomers bonded together. Monomer- one subunit 4 types of carbon based molecules:Carbohydrates- Major source of energyStarches, cellulose, and sugars (starches= potatoes and pasta)Composed of monosaccharide’s primarily glucose.Polymers= polysaccharides= starches, glycogen, and cellulose.Monomers= monosaccharide’s= glucoseMade up of carbon, oxygen, and hydrogen with a 2:1 ration of hydrogen to oxygen.Plants and animals use carbs for the manufacturing and structuring within the cell.Circular structureProteins-Building blocks of proteins are amino acids (20 different)Ribosome’s make proteins.Nitrogen containing compoundsPolymers- Proteins (polypeptide bonds) Monomers- Amino Acids (peptide bonds)Responsible for the composition of enzymes, hormones, antibodies, and structures (muscles)Molecular structure looks like a chain. R group represents the different amino acids. Each one has a different R or side group. Lipids- Fats and oils = water insoluble (cannot dissolve in water)Made up of carbon, hydrogen, and oxygenComposed of glycerol and fatty acids. Can include steroids.Provide insulation, store energy, cushion internal organs, and are found in biological membranes.Saturated= filled with hydrogen, Unsaturated= not filled with hydrogenMolecular structure looks like a long chain with an excessive amount of hydrogen’s! Nucleic Acids- DNA and RNADirect the instruction of proteinsGenetic information an organism receives from its parentsMonomer- nucleotides (a sugar, phosphate, and nitrogenous bases)Polymer- Nucleic acids (DNA and RNA)Made up of nucleotides. Molecular structure looks somewhat like a “U.” Your DNA makes up “U.” Metabolism is the chemistry of life and is always controlled by enzymes!!!ENZYMES!!!* Speeds up rates of reactions, also known as a catalyst.* Lowers activation energy.* Proteins that function to speed up chemical reactions in the cell. * Have specific shape and interact with a specific substrate which binds at the active site.* Regulate nearly every biochemical reaction in the cell. * Different reactions require different enzymes. * Provide energy for cells; build new cells, aid in digestion, and breakdown complex molecules. * Factors that affect enzymes= pH, temperature, and quantity. theory:Cells are the basic unit of life.All organisms are made up of cells.All cells come from pre-existing cells. ProkaryoticEukaryoticNo nucleus or membrane bound organellesDNA is suspended in the cytoplasm and is circularSingle Celled, smaller, less complexCells WallsEvolved 3.5 bya / CyanobacteriaEx- Bacteria Has a nucleus with membrane bound organellesNucleus stores the genetic material and is linearMulticellular or unicellularLarger, more complexPlants and animalsEvolved 1.5 myaBoth Microscopic in sizeComposed of similar building blocksCell MembraneCytoplasmLoaded with ribosome’sHave DNA first to identify cells and name them.Leewenhoek- observed cells in greater detail because he had a better lens.Schleiden- first to note that plants are made up of cells.Schwann- stated that all living things are made of cells.Virchow- proposed that cells come from pre-existing cells. Cell Organelles: Label them!!!!Label the Plant and Animal Cell71.__________________________8.____________________________________2.__________________________9.____________________________________3.__________________________10. ___________________________________4.__________________________11.____________________________________5.__________________________12.____________________________________6.__________________________13.____________________________________7.__________________________14.____________________________________A.______________________________I.________________________________B.______________________________J.________________________________C.______________________________K.________________________________D.______________________________L._________________________________E.______________________________M._________________________________F.______________________________N.__________________________________G.______________________________H.______________________________ / Animal / BothCell MembraneRegulates what enters and leaves the cell membraneBothCell Wall Outer surface that supports and protects the cell. Plant OnlyCytoskeletonHelps the cell maintain its shape and helps some cell parts move about the cell.MicrotubulesIntermediate FilamentsActin FilamentsBothCentriolesShort cylinders that may aid in cell reproduction, but unsure.Animal OnlyCentrosomeMicrotubule organizing center that surrounds the centrioles.Animal OnlyLysosomesVesicles that breakdown and digest old cell parts.Animal OnlyVesicleMembrane bound sac that stores and transports substances (think- endocytosis and exocytosis)BothCytoplasmJellylike fluid that surrounds all of the organelles. Helps transport nutrients, etc throughout the cell as well as serve as a protective cushion.BothGolgi ApparatusProcesses, sorts, packages, and delivers proteins and carbohydrates into vesicles for export out of the cell.Membrane contains enzymesBothMitochondriaSupply energy to the cellConverts food into energy (glucose into ATP)Have their own ribosome's and DNA Site of Cellular or Aerobic RespirationBothRibosomesMake proteins and carry out protein synthesis.BothOrganelleFunctionPlant / Animal / BothSmooth ERNo ribosomesLots of folds, inner membrane= lumenMakes proteins and lipidsControls calcium levels in musclesBreaks down drugs and alcohol BothRough ERCovered in ribosomesAttached to the nucleusProduces, transports enzymes and proteins throughout the cell. BothNucleusControl Center of the cell.Storehouse of DNABothNuclear EnvelopeDouble membrane around the nucleus Protects the nucleusHas pores around it for molecules to pass in and out BothNucleolusDense region in the middle of the nucleusRibosome's are made hereBothNuclear PoreAllows things to move in and out of the nucleus. BothVacuoleFluid filled sacsFull of water, nutrients, and waste that is on its way out. Both CiliaHair like projections that aid in movement.AnimalFlagellaTail like projection that aids in movement. BothChloroplastCarry out photosynthesis by capturing and converting solar energy. Has chlorophyll . PlantCentral VacuoleFluid filled sac used for storage of materials needed by the cell such as water, food, enzymes, and inorganic molecules. PlantPlants have a:Animals have:Cell wall1. Lysosomes (evident in cytoplasm)Central Vacuole 2. Centrioles / CentrosomeChloroplast 3. Cilia (rare in plants)Cell membrane- Composed of a phospholipid bilayer, proteins, cholesterol, and glycoproteins. Semi-permeable membrane that allows certain things into the cell while others are not allowed. * Also called the plasma membrane- control homeostasis* Selectively permeable bilayer= heads and tails. They are the gates to the membrane.Hydrophilic phosphate / glycerol heads= water loving and they face the outsideHydrophobic fatty acid tails= water fearing and they face the inside towards each other. Integral protein = help regulate movement of molecules that are too big to pass through the semi-permeable membrane. Channel Proteins- form small openings for molecules to easily diffuse through. Often used in passive transport. Transport or Carrier Proteins- provides a binding site on the surface of the protein where the molecule can be grabbed and pulled into the cell. They typically change shape when they bind to a target molecule. Glycoproteins= cell recognition, attachmentGlycolipids= protective, cell recognition, provide energyPeripheral proteins= attachment points between the cells and enzymes. Cholesterols- helps strengthen the membrane. Proteins Functions:TransportReceptionCommunicationCellular TransportTwo Types: Passive and ActivePassive Transport- NO ENERGYActive Transport – REQUIRES ENERGY* Movement of substances across the plasma membrane without the use of the cell’s energy.* Goes with the concentration gradient (like swimming with the current).* Diffusion- movement from an area of high concentration to low concentration.* Osmosis- diffusion of water across the cell membrane from areas of high to low concentration. Remember SALT AND SUGAR SUCKS WATER. Where ever the concentration is the highest, that is where the water will go. is the same inside and outside the cell. Homeostasis. Hypertonic- Concentration is greater outside the cell, causing the water to move out of the cell which makes the cell shrivel.Hypotonic-Concentration is greater inside the cell causing the water to flow into the cell resulting in swelling or even rupture. * Facilitated Diffusion- movement of a substance down its concentration gradient through a transport protein. * Movement of substances across the plasma membrane that requires the use of the cell’s energy and carrier / transport molecules.* Goes against the concentration gradient (like swimming upstream).* Moving from high to low concentration.* Membrane pumps- using enzymes to move substances through the proteins in the cell membrane. Ex- most common is the sodium potassium pump.*Endocytosis- large particles are brought into the cell by the cell membrane wrapping around them, pinching off, and forming a vesicle with the molecule. * Exocytosis- Transports materials out of the cell.; Cell membrane is a huge part of this because it regulates what enters and leaves your cells. * Maintains internal conditions such as body temperature, respiration, nutritional balance* Cells communicate needs to each other by sending chemical messages that tell the hypothalamus gland in the brain that a change needs to be made in the interstitial fluid (solution that bathes the cells).* Homeostasis changes all the time, day and night.* Negative feedback (change in a system causes a response that tends to return the system to its original state) = Glucose / insulin levels in cells. Insulin is a natural occurring hormone in the pancreas and when you eat your body turns those carbohydrates into glucose and the insulin opens up those doors in your cells to let the glucose in so that your cells can get back to normal / homeostasis. * Positive feedback= Blood platelets / blood clotting. Wants to accelerate or speed up the process. When you cut yourself and break the blood vessels you want the area to clot rapidly so that you don’t bleed to death. Biochemical Reactions Photosynthesis: Sunlight is the ultimate source of energy for all living things. Process by which producers / autotrophs convert sunlight to chemical energy in the form of glucose. Occurs in the chloroplast where chlorophyll is made in the thylakoid membrane (grana) Occurs in the cytoplasm of prokaryotes. Stroma is the fluid portion where the Calvin Cycle takes place.Functions:Biochemical Process2. Plant Cells only3. Plant growth and development4. Builds plant cell walls= cellulose5. Helps regulate the Earth’s environment6. Removes CO2 from the air 6CO2 + 6H2O + energy --> 6O2 + C6H12O6 (MEMORIZE)(Reactants are to the left of the arrow and products are to the right of the arrow).Light dependent reaction-> Relies on the sunlightStep 1-> Energy is absorbed from sunlight via chlorophyll and other pigments. Energy is transferred to the electrons which enter the ETC. Step 2-> Water molecules are broken down by enzymes and oxygen is released as waste. Step 3-> Electrons jump from protein to protein down the ETC and their energy is used to pump the Hydrogen ions from outside to inside the thylakoid membrane (against the concentration gradient = ACTIVE TRANSPORT) Step 4-> Energy from sunlight continues to be absorbed, energizing electrons and pushing them along the ETC.Step 5-> Electrons are then added to the molecule NADP+ (functions like ADP) to produce NADPH (functions like ATP). Step 6-> Hydrogen ions diffuse through a protein channel. Step 7-> ATP is produced. ADP is changed into ATP when hydrogen ions flow through ATP synthase (enzyme).Light independent reaction-> Uses the ATP from light dependent reactions. ATP is crucial because without it the reaction would not happen. Does not need sunlight Occurs in the stroma and produces sugars Energy sources are ATP and NADPH Energy that is needed for a series of chemical reaction is called the Calvin Cycle, named after the scientist- Melvin Calvin.A molecule of glucose is formed as it stores some of the energy captured from sunlight. Carbon dioxide molecules enter the Calvin cycleEnergy is added and carbon molecules are rearrangedA high-energy three-carbon molecule leaves the cycle1. CO2 is added to the 5 carbons that are already there making a 6 carbon sugar.2. Energy is added. ATP and NADPH (energy carriers) are used from LDR to split the six carbons into 2 groups of 3, and to keep the cycle going.3. Three carbon molecules exit. After they both exit they bond together to form glucose.4. Three carbon molecules are recycled and changed back to five carbon molecules by energy from ATP. It takes two turns of the Calvin Cycle to produce 1 molecule of glucose. Respiration: Releases chemical energy from sugars and other carbon based molecules to make ATP when oxygen is present. Animals use cellular respirationPlants use photosynthesisBreakdown food-> ATPAerobic-> Need OxygenAnaerobic= no oxygenTakes place in the Mitochondria It all starts with GLYCOLYSIS- After you eat and the food is broken down into glucose then the glucose needs to get broken down by glycolysis (2-3 carbon chains, ATP), which takes place in the cytoplasm and is anaerobic. Makes a small number of ATP molecules. Makes 4 ATP, BUT it uses 2 to split up the carbons, therefore only 2 ATP molecules enter the mitochondria. Series of reactions converts the three-carbon molecules to pyruvate / pyruvic acid. Pyruvate (naturally made during metabolism) and NADH are used for cellular respiration.Part 1- The Krebs CycleMain function- transfer high energy electrons to molecules that carry them to the ETCOccurs in the matrix of mitochondriaAlso known as the Citric Acid Cycle because it’s the first molecule formed. Step1- Pyruvate is broken down into 2 carbon molecules and CO2 is released as a waste product. NADH is producedStep 2- Coenzyme A bonds to the 2 carbon molecule made from pyruvate and enters the Kreb’s Cycle.Step 3- Citric Acid is formed- the two carbon molecule binds with a four carbon molecule to make a six carbon molecule which is called citric acid. Step 4- Citric acid is broken down, NADH is made, CO2 is given off as a waste product.Step 5- Five carbon molecule is broken down. Four carbon molecule, ATP, and NADH are formed. NADH leaves the Krebs cycle Step 6- Four carbon molecules are rearranged. High energy electrons are released. NADH and FADH2 (electron carrier) are made Part 2- Electron Transport ChainTakes place along the inner membrane of the mitochondriaMade up of proteinsProteins use energy from NADH and FADH2 to pump hydrogen ions against the gradient (active transport)Step 1- Proteins take electrons. They take 2 NADH and 1 FADH2. Step 2- Proteins use energy from the electrons to pump the hydrogen ions through the inner membrane and the hydrogen ions build up on the inside of the membrane. Step 3- ATP is produced. Flow of hydrogen ions helps make the ATP. ATP synthase adds phosphate groups to ADP to make the ATP molecules. For each pair of electrons that passes through 3 ATP molecules are made. Step 4- Oxygen enters and water is formed. Water is given off as a waste product END RESULT- CO2 and pyruvate (from Kreb’s)H2O from the ETCNet gain of about 38 ATP molecules are made from 1 glucose molecule in an optimal environment. On average the ATP created is 36 ATP!2 glycolysis2 from Kreb’s Cycle32- 34 from the ETCATP- Adenosine TriphosphateOur main energy currency.Molecule that transfers energy from the breakdown of food molecules to cell processes. Cells use ATP to: 1.Carry energy 2. Build molecules 3. Move materials by active transportMade up of the sugar ribose, adenine, and three phosphatesThird bond is unstable so it is easily broken. When 3rd is removed it’s releasing energy and turns into ADP.ATP Process:Step 1- The energy carried by ATP is released when a phosphate group is removed from the molecule. The third bond is unstable and is easily broken.Step 2- Reaction takes place and the energy is released for cell functions, meaning the third phosphate fell off.Step 3- ATP (high energy) then becomes ADP (lower energy molecule) because it just lost a phosphate.Step 4-The molecules get broken down and energy gets added.Step 5- Phosphate is added and it’s back to ATP!Importance- The foods that you eat don’t contain ATP.The food needs to be digested and broken downEverything that you eat has a different calorie amount (measures of energy), therefore different foods produce different amounts of ATP.The number of ATP produced depends on what you eat- Carbohydrates, proteins, or lipids.Carbohydrates yield- 36 ATP per glucose molecule broken downLipids yield 146 ATPFermentationWhen cells do not have enough oxygen in a timely manner the cells continue to produce ATP until oxygen is available again. Glucose is broken down2 types: 1. Lactic Acid Fermentation- muscle cells. 2. Alcoholic fermentation- plant cellsAerobic RespirationAnaerobic RespirationRequires oxygenRelease of energy from the breakdown of glucoseEnergy released is used to make ATP-> provides energy for bodily processes.Takes place in almost all living things.No oxygenBreakdown of food substances in the absence of oxygen with the production of a small amount of energyProduces less energyFermentation Seen as an adaptation for organisms that live in environments that lack oxygen. Chemosynthesis Habitats- hydrothermal ventsAnaerobic bacteriaLive in environments without oxygenChemotrophsEnergy comes from chemical like methane and hydrogen sulfideDNA, RNA, and Protein Synthesis acids are made up of nucleotides (phosphate group, sugar, and nitrogenous base)Found in 1953 by Watson and Crick. DNA- Deoxyribonucleic AcidRNA- Ribonucleic AcidDouble stranded, twisted ladder, double helixControls the production of proteins / RNAStays in the nucleusSugar= deoxyriboseNitrogenous Bases= adenine guanine, thymine, and cytosineBase Pairs= A-T and C-G (they always pair up together- known as Chargaff’s Rule. They match up because they are roughly the same amount in each organism). ReplicationSingle strandedLeaves the nucleus to carry out functions in the cytoplasm.Copy of DNA info. Sugar= RiboseNitrogenous bases= adenine, uracil, guanine, cytosine (instead of thymine we have uracil)Base Pairs= A-U and C-GThree major types- Ribosomal rRNA, messenger mRNA, and transfer tRNA Transcription and TranslationDNA Replication- the process used by cells to copy DNA – an enzyme unzips the DNA by breaking the hydrogen bonds, and each side of the ladder acts as a template for the building of a new strand. The tiny sections are called genes. Sequence of bases determines sequence of amino acids in proteins.Helicase (Enzyme)- unzips the hydrogen bonds that hold the nitrogenous bases together.DNA Polymerase (Enzyme) – brings the two strands back together again once they have replicated. Example of old strand= TACGGACExample of new strand= ATGCCTG the process of making RNA from DNA.Remember the T is replaced with U!!!Example of the DNA strand = TACGGACExample of the RNA built= AUGCCUG Three types of RNA:mRNA- messenger- it’s the blueprint for how to build a protein. Carries messages to the ribosomes. tRNA- transfer- carries amino acids to ribosomes. Remember amino acids are the building blocks of proteins! rRNA- ribosomal- makes up a ribosome. * RNA polymerase is the enzyme responsible for bonding the nucleotides together in a chain to make new RNA. that converts mRNA into a polypeptide = proteins! The process of building a protein by matching codons in mRNA to anticodons of tRNA. Codons= sequence of three amino acids nucleotides that code for a specific amino acid (remember there are 20). Anticodons- set of three nucleotides that are complementary to an mRNA codon. Example= the anticodon for CCC is GGG. Held together by covalent bonds= very strong!SugarPhosphateHydrogen Bonds- they break when the DNA needs to replicate. CGATBase Pairs make up the rungs of the ladder and they always attach to the sugars not the phosphates!!!A-TC-G ReproductionAsexual ReproductionSexual Reproduction1 parentGenetically identical offspringNo gametesFast, efficient, less energy = advantagesNo variation and susceptible to population wipeout = disadvantagesBinary fission- one bacterium becomes 2 through growing and splitting.Budding- growth off the side of the parent like hydras and spongesFragmentation like a worm. Regeneration like a sea star. Arm falls off and re-grows.2 parentsFusion of gametes-> sperm and eggOffspring are genetically differentSlower, less efficient, and more energy = disadvantagesHuge amounts of variation and can adapt to changing environments = advantagesInternal fertilization= sperm meets eggs inside the female.External fertilization= spawning-> eggs and sperm are released into the water.Meiosis= 4 genetically different haploid cells. Cell DivisionProcess of copying and dividing the entire cell.Results in daughter cells being produced.Mitosis results in 2 identical daughter cells.Meiosis results in 4 genetically different haploid cells.Haploid- having one set of chromosomes (n) gametes- sperm / egg. Haploid number =23Diploid- having two sets of chromosomes (2n)- body cells- one set is from mom and one is from dad. Diploid number = 46Cell Cycle- A regular pattern of growth, DNA replication, and cell division that occurs in eukaryotic cells.5 main stages: First three are Interphase.1. Gap 12. Synthesis3. Gap 24. Mitosis5. CytokinesisInterphase- First Stop and the longest phaseGap 1 or G1 Synthesis or S Phase Gap 2 or G2 Cell growth Cells increase in size and organelles increase in number Critical checkpoint to make sure that the DNA is perfect and that there are no imperfections. Copies the DNA- DNA Replication, Transcription and Translation occur here. By the end the cell’s nucleus contains two complete sets of DNA. Additional growth Critical checkpoint to make sure that the DNA is not damaged and that the cell is adequate size. Mitosis- division of the cell’s nucleus. Terminology:Chromosomes- long continuous strand of DNAHistones- A group of proteins that your chromosomes are associated with.Chromatin- loose combination of DNA and proteins, looks like spaghettiChromatid- one half of the duplicated chromosome.Centromere- the center where sister chromatids are held together.Telomere- the ends of DNA molecules and they prevent the chromosomes from accidently attaching to one another as well as gene loss. Prophase- chromosomes are duplicated and spindle fibers form. Nuclear membrane breaks down.Metaphase- chromosome line up along the cells equator between the spindle fibers.Anaphase- chromosomes are pulled apart to opposite sides of the cellTelophase- nuclear membrane reappears, spindle fibers disappear, and chromosomes disperse. division of the cytoplasm.2 identical daughter cells are the end result has two types of cells:Somatic Cells or Body cellsGerm Cells or Sex CellsMakes up most of your body and tissues.Ex- heart, kidneys, eyeballs, etc.DNA in your body cell is not passed on to your children. Cells in your reproductive organs.Ovaries and testes that develop into sperm and eggs= your gametes. DNA is spread to your child. Autosomes and Sex Chromosomes:23 pairs of chromosomes = 46 total in humansGet 23 from mom and 23 from dadEach pair = homologous chromosome = means having the same structure.Homologous Chromosomes- two chromosomes, one from mom and one from dad, which have the same length and general appearance.The chromosomes have copies of the same genes but they may differ.Autosomes are chromosome pairs 1-22 and are not related to the sex of an individual.Sex Chromosomes:Pair number 23In Humans- XY= male, and XX= femaleThey are not homologousX chromosome is larger and carries more genes than the Y, which is smaller and carries fewer genes.Karyotype- picture of all of your chromosomes Results in 4 genetically different Haploid CellsTwo rounds: Meiosis 1 and Meiosis 2Meiosis 1- divides the homologous chromosomesMeiosis 2- divides the sister chromatids Reduces chromosome number and increases genetic diversitySex Cells or gametes that are dividing. 1-Homologous pairs formChromosomes trade genesNuclear membrane breaks downCentrioles move to opposite sidesSpindle fibers assembleLongest phaseCROSSING -OVER Metaphase 1-Homologous chromosomes are aligned in the middle by spindle fibers.23 chromosomes line up along each side of the equator- some from mom and some from dad. Each side of the equator has chromosomes from both parents.Anaphase 1-Homologous chromosomes separate to opposite sides of the cell.Sister chromatids remain attached together. Telophase 1-Spindle fibers fall apartNuclear membrane may reformCell undergoes cytokinesis End result= 23 unique duplicated chromosomes from both parentsProphase 2-Nuclear envelope breaks downCentrosomes and centrioles move to opposite sides of the cell. Spindle fibers form Metaphase 2-Spindle fibers align chromosomes along the cells equator.Anaphase 2-Sister Chromatids are pulled apart from each other to opposite sides of the cell.Telophase 2- Nuclear Membranes form around chromosomesSpindle fibers fall apartCell undergoes cytokinesis Results in 4 genetically different haploid cells. ................
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