AP Bio notes Big Idea 3

Gene Pool- A collection of all the genes in the population Genetic Drift- describes random fluctuations in the numbers of gene variants in a population -occurs more frequently in small populations -often a trait is completely lost Bottleneck Effect- A drastic reduction in the population size and the change in allele frequency Founder Effect: occurs when a few individuals become isolated from a larger population -New species Barriers to Reproduction: Prezygotic- Impede mating -Habitat isolation -temporal isolation -Behavioral isolation -Mechanical isolation -Gametic isolation Postzygotic- Prevent hybrid zygote from developing into viable adult -Reduced hybrid viability -Reduced hybrid fertility -Hybrid breakdown Allopatric- Different environments Sympatric- Genetic recombination in sexually reproducing organisms can result in variation -Horizontal Gene Transfer Great American Interchange Many new species arise from a common ancestor Occurs when a few organisms make way to new, distant areas Environmental change to extinctions to new niches for survivors Adaptive Radiation: evolution of a group of diversely adapted species upon introduction to a new environment Hawaiian plants descended from ancestral tarweed from North American 5 million years ago Sexual selection: Form of natural selection- certain individuals more likely to obtain mates Sexual dimorphism- differences between 2 sexes Intrasexual- selection within same sex Intersexual- mate choice Miller and Urey- Tested Oparin- Haldane hypothesis Simulated early earth conditions Produced amino acids NH4, CO2, CH4, H2O Endosymbiotic Theory- Lynn Margulis Mitochondria and plastids formed from small prokaryotes living in larger cells Evidence: Replication, circular DNA (No histones) Ribosomes to make proteins Enzymes similar to living prokaryotes Two membranes Tempo of evolution Gradualism Common ancestor Slow constant change Preserving Genetic Variation Diploidy: hide recessive alleles that are less favorable Heterozygote advantage: Greater fitness than homozygotes SS= Sickle cell AS= Heterozygous AA= Homozygotes Where is sickle cell disease most prevalent? Why? People of African descent because people in Africa are more prone to malaria so the sickle cells are a lot harder to infect with malaria. What do the alleles stand for? Is it rare? No Archaea, Eubacteria, Fish, Amphibians, Reptiles, Mammals, Aves Systematics: Classifying organisms and determining their evolutionary relationships - Taxonomy- classification - Phylogenetics- evolutionary history Fossils Morphology Molecular evidence Clade- Group of species that includes an ancestral species 3 domains: Bacteria:+/-, good or bad, peptidoglycan Archaea: Cannot make us sick, extremophiles, Eukaryotic: Nucleus, multi celled Archaea differ from eubacteria many key structural, biochemical, and physiological characteristics Peptidoglycan in cell wall Prokaryotes thrive in habitats that are too cold, too hot, too salty, too acidic, to alkaline for any Eukaryotes Halophiles- salt Thermophiles- Hot/sun Barophile- High pressure Acidophiles- Acid Polyextremophile- Deinococcus radiodurans- Can survive many harsh environment, DNA repairing mechanism Origin of life- 3.5-4 BYA- Cyanobacteria Origin of life of Photosynthesis- 3 BYA Origin of Eukaryotes- 2 BYA Multicellular life- 1 BYA Origin of animals- 600 MYA Heterotroph hypothesis- Chapter 4- Cell structure Scopes Light: -Visible light passes through specimen -Refracts light so specimen is magnified -Magnify up to 1000x -specimen can be alive -color Electron: -Focuses a beam of electrons -Magnify up to a milli times -nonliving -Black and white Cell fractionation- take apart cells, separate major organelles Prokaryotic- No nucleus No organelles other than ribosomes Small size Eukaryotic- Membranes, nucleus Cells must be small to maintain a large surface Large S.A. allows rates of chemical exchange between cell and environment Surface area- Small Intestine Villi Ribosomes Composed of rNA & protein Large subunit+small subunit Free ribosomes: float in cytosol, produce proteins used within cell Bound ribosomes: attached to ER make proteins for export from cell Endoplasmic Reticulum is like the liver Golgi Apparatus :synthesis and packaging of material for transport Cis = receives Trans = ships vesicles Lysosomes Intracellular digestion; recycles cell’s materials Contains hydrolytic Vacuoles Storage of materials Mitochondria- Site of cellular respiration C 1=E 2=A 3=E 4=E 5=B 6=C Chloroplasts -Site of photosynthesis - Thylakoid disks in stout hacks Peroxisomes Breaks down fatty acids Involves production of hydrogen peroxide Cytoskeleton Network of protein fibers Support, motility, regulate biochemical activities Microtubules Protein=tubulin Largest fibers Tracts for organelle movement Forms spindle for mitosis Component of cilia Microfilaments Protein=actin Smallest fibers Cell movement Intermediate Filament Actin and Tubulin Fix position of organelles. Cilia and Flagella Flagella: Long and few, propel through the water Extracellular Matrix Outside plasma membrane Composed of glycoproteins Strengthens tissues and transmits external signals to cell> stem cells Tight Junction When two cell membranes are virtually impermeable to fluid Helps stabilize cell structure Prevents molecules from moving into cells Highest % in the bladder, liver Gap Junction A specialized intercellular connection between a multitude of animal cells Directly connects the cytoplasm of two cells which allows various molecules and Ions to pass freely between cells Involved in cell to cell communication Desmosome A cell structure specialized for cell to cell adhesion Very random Allows water and ions to pass Found a lot in skin and intestines Most abundant in the muscle cells The Cell membrane Phospholipids Hydrophilic Fatty acids tails Hydrocarbons Arranged as a bilayer Polar=unevenly charged Non Polar=evenly charged Water Glucose Ions Urea Non Polar CO2 O2 Polar hydrophilic heads Within membrane Non polar amino acid outside=polar amino acids Peripheral proteinLoosely bound to surface of membrane ATP- Adenosine Ribose Phosphate Organisms are endergonic Energy coupling Use exergonic reactions to power endergonic Adenosine TriPhosphate When the bonds break- Spring loaded, releases a lot of energy ATP- ADP -Phosphorylation Enzyme that phosphorylates= Kinase Building Polymers from Monomers- connecting amino acids Cell to cell signaling- turns on and off certain enzyme activities and transcription of proteins Oxidative Phosphorylation- Changing ADP to ATP NADH!!!!! ATP Synthase Glycolysis- Step one of cell respiration Glycolysis is in cytosol Link reaction is in cytosol The Krebs cycle is in matrix Electron transport chain is in intermembrane 10 reactions convert glucose (6c) to 2 pyruvate Produces 4 atp and 2 NADH Consumes 2 ATP Yields 2 ATP and 2 NADH Phosphorylate glucose Phosphate came from pep Lactic acid Fermentation DNP Oxidation of pyruvate- Link reaction or transition step Releases 2 co2 Reduces 2 AND-2 NADH Produces 2 acetyl CoA Acetyl CoA enters Krebs cycle 2x (yield=2C sugar+NADH+Co2) AKa citric acid cycle In Mitochondrial matrix 8 step pathway Each catalyzed by specific enzyme Step wise catabolism of 6C Citrate molecule Evolved later than glycolysis Bacteria 3.5 billion years ago Free O2 2.4 billion years ago Eukaryotes 1.5 billion years ago Aerobic respiration Oxaloacetate forms citrate How much per turn. 2 turns per molecule of acetyl CoA 2 CO2 3 NADH 1 ATP 1 FADH2 ENDED UP WITH 4 ATP after Krebs cycle End result of Krebs cycle is to hold onto electron carriers, NADH and FADH2 Electron transport chain Series of proteins built into inner mitochondrial membrane Along cristae Transport proteins and enzymes Transport of electrons down ETC linked to pumping of H+ to create H+ gradient Yields about 36 ATP from Electrons stripped from H atoms to H+ Electrons passed from one electron carrier to next in mitochondrial membrane Transport proteins in a membrane pump H+ across inner membrane to intermembrane space What is the final electron acceptor? Oxygen Che Osmosis The diffusion of ions across a membrane Chemiosmosis uses CO, Sulfur, Oxygen Peter Mitchell Proposed chemiosmotic hypothesis What happens if O2 is unavailable ETC backs up Cells run out of energy and you like die Ribozymes Plants need O2 to respire Heterotroph- eat other stuff Autotroph- photosynthesis Heterotroph- Oxidation= exergonic Autotrophs- reduction= endergonic CO2+H2O=H2CO3 What is a plant? Need to get building block atoms from the environment C,H,O,N,P,K,S,Mg 1st Photosynthetic Bacteria Cyanobacteria- Chloroplasts Red and Brown Algae Land plants COOKSONIA Sunlight- leaves CO2- Stomatal= gas exchange H20- Uptake from roots Nutrients- N,P,K,S,Mg,Fe… Uptake from roots Light dependent- Photolysis (light photons split water in granum) Light independent- Calvin cycle- in the stroma Makes glucose Chlorophylls and other pigments Embedded in thylakoid membrane Photosystem- collection of chlorophyll Photosynthesis gets energy by absorbing wavelengths of light -Chlorophyll a - absorbs best in red and blue wavelengths and least in green. 2 photosystems in thylakoid membrane Act as light gathering molecules Photosystem 2 Chlorophyll a Photosystem 1 Chlorophyll b Electron transport chain of photosynthesis 4 proteins -Etc uses light energy ATP and NADPH PS 2 absorbs light Enzyme extracts electrons from H2O and supplies them to chlorophyll Splits H2O O combines with another O to form O2 Where did the O2 come from? Radioactive tracer= O18 6CO2 +6H2O + light energy - C6H12O6 + 6O2 O2 from water goes to oxygen O2 goes from CO2 goes to glucose Noncyclic Photophosphorylation Noncyclic is better than Cyclic (Bacteria are Cyclic, can’t make NADPH, not as efficient) Light reactions elevate electrons in 2 steps PS2 PS1 PS2 generates energy as ATP PS1 generates reducing power as NADPH From light reactions to Calvin Cycle Calvin cycle occurs in Chloroplast Stroma (Light independent) G3P=pyruvate Calvin cycle Carbon fixation (important!!!) Turns Co2 into solid releases O2 Most important enzyme Rubisco (RuBp) Reduction- Building Pyruvate by Rubisco + CO2 Regeneration of Ribulose- Need more Rubiscot, uses ATP 3 Molecule of CO2 makes one molecule of G3P How many CO2 molecules are needed to make glucose? 6 Glyceraldehyde-3-P End product of Calvin cycle Energy rich 3 carbon sugar C3 Photosynthesis makes pyruvate G3P can become anything the plant needs Calvin Cycle 1- carbon fixation 2- reduction 3- regeneration of rubisco Accounting 3 turns of calvin cycle= 1 G3P 3 CO2- 1 G3P 6 Turns of Calvin cycle = 1 C6H12O6 6 CO2 Light reactions Produce ATP Produce NADPH Consumed H2O Produced O2 as byproduct Calvin Cycle Consumed CO2 Produced G3P Regen ADP Regen NADP Light Reaction 1=H2O+Light energy- ATP + NADPH +O2 Produces ATP Produces NADPH Calvin Cycle= CO2 + ATP + NADPH- C6H12O6 + ADP + NADP Builds sugar CO2 + H2O + light= C6H12O6 + O2 258 Billion tons captured C4 and CAM Plants Tonoplast, Stomata (Time), Spines---- Desert plant adaptations Closed Stomata leads to -O2 build up -Co2 is depleted is calvin cycle Inefficiency of RuBisco -Carbon fixing enzyme - CO2 is the optimal substrate - Reduction of RuBP -Building sugar When O2 concentration is high- Photorespiration NH3 is a toxin in plants and NH3 is made during Photorespiration Loss of Carbons to CO2 Can lose 50% of carbon fixed by Calvin Cycle C4 plants Physically separate carbon fixation from Calvin cycle Different cells to fix carbon vs where Calvin cycle occurs Store carbon in 4C Different enzyme to capture Co2 PEP Different leaf structure CAM Plants Separate carbon fixation from calvin cycle by time of day C4 and CAM plants make more food and clean the air PEP Carboxylase Store as 4C Compound (Malate) Vascular Bundle is the Xylem and Phloem CAM (Crassulacean Acid Metabolism) BIG IDEA 3 Mitosis and Meiosis: Basic Cell Division: Mitosis Produce cells with same info Exact copies Same amount of DNA/number or chromosomes Same genetic info Repair Growth Regeneration Reproduction Asexual reproduction Single celled eukaryotes Yeast protists Number 23 is a sex chromosome and doesn't do much other than gender 1-22 are autosomes Homologous chromosomes Both chromosomes of a pair carry matching genes Miosis Special cell division for sexual reproduction Makes sex cells Prophase 1 Crossing over Chiasmata is where crossing over occurs Crossing over Cross over- Endonuclease Breaking of DNA- Polymerase Refusing of DNA- Ligase Extra credit!!!!!! Telomerase Meiosis-fertilization-mitosis+development Oogenesis Eggs in ovaries halted before Anaphase 1 Meiosis 1 completed during maturation 1 egg and 3 polar bodies 3 polar bodies goes into apoptosis DNA=Deoxyribonucleic Acid Phosphate PO4- Ribose Base (A,T,C,G) Nucleotide codes for protein Codon: a 3 digit letter sequence that codes for amino acid Beneficial or deleterious mRNA codon chart Wobble effect- third letter is changed or mutated can be a new amino acid or not work AUG- start Errors in Mitosis lead to disease(cancer) Errors in Meiosis lead to pre-congenital disease Nondisjunction Anuy Klinefelter's- genetics at least one extra X chromosomes to a standard human karyotype Turners syndrome: Females born with only 45 chromosomes; missing one x chromosomes Cystic Fibrosis: A mutation in the CFTR gene An autosomal recessive genetic disorder Affects mostly the lungs but also the pancreas, liver, and intestine TH Morgan- discovered chromosomes- grandson of francis scott key Frederick Griffith Deadly bacteria =S Harmless=R DNA is Universal Horizontal gene transfer Avery, McCarty and MacLeod First experimental evidence that DNA was the first genetic material Inject protein into bacteria Injected DNA into bacteria Hershey and Chase Bacteriophage Chargaff DNA comp c=g a=t Structure of DNA- Watson and Crick Developed the double helix Replication of DNA Base pairing suggests that it will allow each side to serve as a template for a new strand Dispersive Conservative Semi conservative Meselson and Stahl Label parent nucleotides in DNA strands with Heavy Nitrogen Label new nucleotides with lighter isotope\ The central Dogma DNA continued from gene to protein Lack of an enzyme Tay Sachs PKU Albinism Beadle and Tatum One gene: one enzyme hypothesis RNA- Single stranded Transcription- Making mRNA Transcribed DNA strand= template strand Untranscribed DNA strand = coding strand RNA polymerases RNA polymerase 2 Transcribes genes into mRNA Okazaki fragments Splicing results in bio variability/ mutations Error results in non functional protein results in diseases Immune system is where splicing takes place (MHC) lets white blood cells make any protein Translation from nucleic acids to amino acids Nirenberg and Khorana - but together letters/codon chart Start- Aug Stop- UGA, UAA, UAG TRNA- 31 kinds -TRNA clover leaf shape -anticodon on bottom Aminoacyl TRNA synthetase- Bonds amino acid to tRNA Ribosomes- Facilitate coupling of tRNA anticodon to mRNA or enzyme Ribosomal RNA and proteins make it up A site- holds tRNA carrying next amino acid to be added to the chain P site- holds tRNA carrying growing polypeptide chain E site (exit site)- empty tRNA leaves ribosomes from exit A- initiation P- elongation Operons- Prokaryotic gene expressions Prokaryotes have no nucleus Transcription and translation happen at the same time Transient- the bacteria needs to act quickly to adapt to new food sources Gene regulation in Bacteria Cells vary amount of enzymes by regulating gene transcription , turn genes on or off Jacob and Monod: Lac operon First to describe operon system Operon Genes grouped together with related functions Promoter RNA polymerase binding site Operator DNA binding site of repressor protein Repressor protein Binds to DNA at operator site Blocking RNA polymerase Blocks transcription Inducible breaks stuff down catabolism Repressible makes stuff Repressible operon: tryptophan Anabolism- makes stuff Repressible operon- stops making stuff - enzyme on repressible turns off Anabolic is making stuff Inducible operon catabolic -enzyme on inducible turns on Makes stuff to break stuff down Eukaryotic Gene expression: Control Points Gene regulation Turn genes on and off quickly Adjustable levels of enzymes for synthesis and digestion Regulate body as a whole Growth and development Specialization Most coordinate the body as a whole rather than serve the needs of individual cells H.G.H and Insulin- negative feedback Labor- positive feedback The control of gene expression can occur at any step in the pathway from gene to functional protein Packing and unpacking DNA- Packed too tight, can’t express gene. Packed loosely, can express DNA coiling and folding Double helix Nucleosomes Chromatin fiber Looped domains Nucleosomes- 1st level of DNA packing Histone proteins 8 protein Positively charged amino acid Bind tightly to negatively charged DNA- PO4- Transcription mRNA processing- Splicing mRNA transport- Where the mRNA goes Translation- Can stop making protein Protein processing- Designating where protein goes and what it does Protein degradation- Chromatin Heterochromatin- darker DNA= tightly packed Euchromatin- Lighter DNA= loosely packed Methylation of DNA- Blocks transcription factors No transcription Genes turned off Permanently inactivated genes Acetylation of histones unwinds DNA Loosely wrapped around histones Genes turned on Transcription initiation Promoter Binding of RNA polymerase and transcription factors Enhancer Distant control sequences of DNA Bonding of activator proteins Enhanced rate of transcription Operator= bacteria Enhancer= Eukaryotes Post-transcriptional control Alternative RNA splicing Introns get spliced so exons can be expressed Regulation of mRNA degradation Add poly(a) tail to 3’ add cap to 5’ RNA interference Small interfering RNA Bind to mRNA Binds to a promoter to turn it off Opposite of enhancer Control of translation Blocks translation of mRNA to protein Protein processing Targeting for transport Protein degradation Ubiquitin tagging- death tag Proteasome degradation Mendel- Law of dominance Segregation indep assortment 3 to 1 Phenotype- Description of an organism's physical trait Genotype- description of makeup Law of segregation Alleles segregate Metaphase 1 Each gene has 2 alleles, 1 of which is dominant to the other Incomplete dominance Heterozygote shows an intermediate Blended phenotype Codominance 2 alleles affect the phenotypes equally and separately Pleiotropy Most genes are pleiotropic One gene affects more than one phenotypic character Acromegaly Achondroplasia 0` Gel Electrophoresis- A method by which DNA,RNA, or proteins are separated in a gel Small- The fastest Biotechnology Bacterial genome Haploid Naked DNA No histone proteins 4 million base pairs Transformation Bacteria are opportunists Pick up naked foreign DNA Import bits of chromosomes from other bacteria Plasmids Small supplemental circles of DNA Self replicating Carry extra genes Can be exchanged between bacteria Vector is a plasmid Restriction enzyme Evolved in bacteria to cut up foreign DNA Restriction enzymes cut at restriction sites Electrophoresis Identify traits Diagnostic Forensics Evolution Non coding dna- Introns Restriction Fragment Length polymorphism Dna that is unique to you 1987 P.C.R Polymerase chain reaction- Amplify DNA Template strand DNA Polymerase Nucleotides- ATP, GTP, CTP, TTP Primer Plasmids -building custom plasmids DNA Hybridization Finding short sequences of DNA using a labeled Probe Complementary to part of gene of interest Labeled radioactive P32 DNA libraries Cut up all of nuclear DNA from many cells of an organism Clone all fragments into many plasmids at same time Reverse transcriptase Hiv DNA Library- Genome in a plasmid Reverse Transcriptase RNA- DNA Mating with yeast- Identify their mates by chemical signaling A signal transduction pathway is a series of steps by which a signal on a cell's surface is converted into a specific cellular response Quorum sensing- cells of many bacteria species secrete small molecules that can be detected by other bacterial cells and influence gene expression- Paracrine- nearby Morphogen gradient Autocrine signaling- Cancer cells, apoptosis Juxtacrine- Plasmodesmata and gap junction, quorum sensing Long-Distance signaling Nervous system in Animals Electrical signals through neurons Endocrine system in Animals Uses hormones to transmit messages over long distance Plants also use hormones Some transported through vascular system Others are released into the air Epinephrine released from adrenal glands Cell receptor receives message Glycogen turns into glucose G- protein- 7 domains Involved in transmitting a signal to the nucleus of a cell through its cell membrane Binding of GTP activates it… binding of GDP deactivates it Involved in everything Receptor tyrosine kinases 2 receptors are involved to form a dimer Can actually 10 or more proteins Most involved in growth or metabolism Ion channel reception - very important in the nervous system - Signal triggers the opening of an ion channel - depolarization (action potential) - triggered by neurotransmitter Acetylcholine- Ca dopamine/serotonin cAMP- Cyclic IP3- Soluble NO CA+- Involved in muscle contraction Pathogenesis - Komodo Dragon starfish DAP Response- Many outcomes Blotting takes 30 min Scaffolding proteins Can increase the signal transduction efficiency Long distance signaling Intracellular signaling includes hormones that are hydrophobic and can cross the cell membrane Reuptake inhibitor- depression ADG VS Cortisol negative feedback Apoptosis Cell is dismantled and digested Caspase- breaks down cells Why? We don't need this anymore Osteoblast- makes bones Osteoclast- destroys G- proteins are diseases!!! Ion channels- movement Scaffolding protein Viagra Inhibits hydrolysis of c BIG IDEA 4 Anatomy- Structure Physiology- How we use it Animal form and function are correlated at all levels of organization Cells of growing embryo differentiate into 3 tissue levels Endoderm, mesoderm, ectoderm Hierarchical Organization of body of body plans Organelles-cells-tissues-organs-organ systems Four main types of tissues- Epithelial Covers the outside of the body and lines the organs and cavities within the body Connective Binds and supports other tissues Cartilage, tendons, ligaments, bone, blood, adipose Muscle Controls body movements Skeletal, smooth, cardiac Nervous Senses stimuli and transmits signals throughout the animal Neurons, glia Cuboidal Epithelium- kidneys Stratified squamous epithelium- mitosis, cancer GLIA is the powerhouse of the brain Thermoregulation Endothermic- makes energy Ectothermic- Gives it away Insulation Circulation Adaptations Cooling by evaporative Behavioral responses Antifreeze Basal Metabolic rate- Endotherm Standard metabolic rate- Ectotherm Tropism- How a plants responds Auxin- The plant hormone auxin Gibberellins- Plant hormones that regulate growth Cytokines a class of small proteins and hormones that are involved in plant growth Barrier White blood cells Immunity Complement system Attack bacterial and fungal cells Form a membrane attack complex Basal cells interleukin -1- fever B- cells- bring protein to surface T cells- kill Myeloid- Neutrophil- kill anything Antigens can be good or bad Lymphocytes B cells In bone marrow Plasma cells Immediate production of antibodies Memory cells Long term immunity T cells Mature in thymus Humoral- fluid Antibodies proteins that bind to a specific antigen Must be specific T helper cells show antigens 7 Acquired immunity vs passive immunity A.P.C cells and M.H.C Antigen presenting cells Full immune response takes 10 to 17 days DNA rearrangement and somatic mutation vertebrates can produce millions of B and T cells Vaccinations are for viruses Immune system exposed to harmless version of pathogen Triggers active immunity Jonas Salk Developed Polio that gave you 99% chance of survival Iron Lung Passive immunity Obtaining antibodies from another individual Paternal immunity Antibodies pass from mother to baby across placenta or in mothers milk Injection of antibodies- serum Short term immunity T cells Cell mediated response Immune response to infected cells Defense against “non self” cells types - Helper T Cells- alerts the immune system Killer T cells Thymus is used to hold T Cells CD4 cells low count is aids Major histocompatibility (MHC) proteins- Only reason we can make antibodies antigens - glycoproteins MHC proteins constantly carry bits of cellular material from the cytosol to the cell T Cell Response- Retroviruses and Autoimmune Disease Adaptive immunity- getting sick and making antibodies Vaccines Passive- mothers milk Key attributes of the immune system- Specificity- antibody specificity Diversity- MHC Memory- B cells Ability to distinguish self vs non self- Failure results in autoimmune disease Lytic vs Lysogenic cycle- Lysogenic cycle ends in cell death Lytic cycle- making copies M.H.C- splicing, mutating Perforin- death tag cell HIV and AID HIV- virus infects helper T cells Helper T cells don’t activate rest of immune system CD4/CCR5- receptors for aids YOU HAVE TO T9 4 =AKE A.Z.T KINSHASA- Bonus!!!- Town where HIV was traced back to. Acquired ImmunoDeficiency Syndrome Death from other infections Delta 32- Bonus!!! The gene responsible for not having either CD4 or CCR5- Where aids attaches to. No CD4 or CCR5, to Aids AIDs is Reverse Transcriptase RNA- DNA then DNA-RNA Components of a mammalian nervous? Brain, spinal cord Who has a nervous system? Coral to human CNS- central nervous system Autonomic Parasympathetic Resting and digestion Sympathetic Fight or flight response PNS- Peripheral nervous system Somatic Skeletal muscles Afferent- sensory Efferent- motor Why a nervous system? -Fast -accurate -reset quickly Hypothalmus Neuron- nerve cell Many entry points for signal One path out Transmits signal Synapse- space in between neurons Myelin sheath degradation= MS 3 kinds of neurons Sensory (1) Motor (3) Interneurons (2) Starts with sensing something, gets sent to brain, locomotion Transmission of a signal Start the signal Propagate the signal Reset the system All or nothing response NA+ CL- Ions that neurons use Anions (negative) More concentrated in the cell CL-, charged amino acids Cations (+0 More concentrated in the extracellular fluid NA+ 3 NA goes in 2 CL goes out Cells have voltage Membrane is polarized Resting potential of -70 mV Has to get up to -55 mV Nerve impulses travel in a wave Wave moving down neuron= Action potential Change in charge opens voltage gated channels ie ion channels Stimulus- nerve is stimulated Reaches threshold potential- -55mV Charge reverses on neuron Cell becomes depolarized Reseting K channels open K channels open more slow than NA channels K ions diffuse out of cells Charge reverse back at that point Negative inside, positive outside Wave= nerve impulse, or action potential Brain- finger tips in milliseconds Afferent vs efferent Afferent- sensory neurons Efferent- Motor Neurons Sodium potassium pump Antiporter Requires ATP 3 NA+ out 2 K+ in Batrachotoxin Arrow frog Snakes release Nerotic Cytotoxins Resting potential Stimulus reaches Depolarization NA+ channels open K+ channels closed 4. Na+ channels close K+ channels open 5. Repolarization, reset 6. Undershoot K+ channels close slowly 2 milliseconds!! Acetylcholinesterase Enzyme which breaks down acetylcholine neurotransmitter Myelin sheath Axon coated with Schwann cells Insulates axon Speeds signal Saltatory conduction 330 MPH How come cells with the same DNA differentiate into different kinds. Regeneration Oogenesis Unequal meiotic divisions 1 egg 3 polar bodies Fertilization- Fusing of egg and sperm to for a zygote in fallopian tube Cleavage- repeated mitotic divisions of zygote Unequal divisions establishes body plan Morphogen creates a gradient zygote - morula - Gastrulation- ectoderm Outer body tissues Skin nails, teeth mesoderm Middle tissues Blood and lymth, bones Inner lining Digestive system. Neurolation Formation of notochord and neural tube develop into nervous system Organogenesis- development of the organ system -placenta forms.- Allows for exchange across membranex Chorion- releases water when birth coming Amnion- Chorionic villus sampling- used to make karyotype Oogenesis Fertilization Zygote Cleavage Gastrulation Neurulation Organogenesis AP Bio Notes- Breathe By:Hanna Scali We need a respiratory system to take in O2- for aerobic cellular respiration and to make ATP, 20% Need CO2 out- waste production from krebs cycle, 16% Gas exchange- O2 and CO2 exchange between environment and cells- 800 mL of water needed Needs moist membrane and needs high surface area Gills in a fish are actually called operculum Water carrying gas flows in one direction and blood flows in the opposite direction Blood should flow out of the mouth of the fish and pumped to the gills The process that fish breathe is called the countercurrent exchange Advantage of terrestrial life- air is much lighter than water and therefore easier to pump, O2 and CO2 can diffuse much faster Disadvantages- keeping large respiratory surface moist causes high water loss Tracheae- air tubes branching throughout body, gas exchange by diffusion across moist cells lining in terminal ends, not through open circulatory system Caterpillars use spiracles(little holes in their sides) to get air in 1) pharynx 2) tracheae 3) bronchus 4) bronchiole 5) alveoli- gas exchange across thin epithelium of millions of alveoli Negative pressure breathing- breathing due to changing pressure in lungs Breathing in increases the pressure and breathing out decreases it and doesn’t take energy Excretion and Water balance Kangaroo rat- does not drink Superworm turns into a bug American toad- absorbs it Two evolutionary paths Regulate internal environment Maintain relatively constant conditions Conform to external environment Allow internal conditions to fluctuate Thermoregulation- temp control Osmoregulation- water control Overcoming limitations of diffusion Evolution of exchange system for Distributing nutrients Removing wastes Excretory system Respiratory system Integumentary system Osmoregulation Water balance Hypotonic Water flows into cells and salt cell Saltwater Hypertonic Water loss from cell Land Dry environment Conserve water May also need to conserve salt Carbs= CHO Intracellular waste products Lipid=CHO Proteins= CHON N= Nitrogen ORCA WHALE- Bonus question???? Ammonia= NH3 Very toxic Very soluble Must dilute it and get rid of it fast Nitrogen waste Aquatic organisms Can afford ammonia Terrestrial Need to conserve water Urea Terrestrial egg layers Need to conserve water Need to protect embryo in egg Uric acid Least toxic Urea= larger molecule= less soluble= less toxic 2NH2+CO2 Kidney Filter solutes out of blood Reabsorbs H20 Excrete waste Egg laying land animals Nitrogen waste disposal No place to get rid of waste in egg Need even less soluble molecule B Cycles in Ecology Organism Population Community Ecosystem Biosphere Ecosystem- All the organisms in a community plus abiotic factors Ecosystems are transformers of energy and processors of matter Ecosystems are self sustaining Energy flows Capture energy, transfer energy, cycle nutrients N2-- NO3- NO2 Eutrophication Deforestation breaks the water cycle Ground water is not transpired to the atmosphere Anoxic- lack of o2 Repairing the damage The Greenbelt Movement Planting trees in Kenya Restoring a sustainable ecosystem Population ecology Food chain Trophic levels Feeding relationship Start with energy from sun Captured by plants Efficient transfer of energy Abiotic- sunlight -precipitation - soil Biotic- prey Competitors predators Dependent are biotic Abiotic are independent Intrinsic factors- Adaptations DNA Population Group of individuals of same species in the same area at the same time Population spacing Size of population Monoculture At risk populations Critically endangered species- dozens or none left Population spacing clumped - packs- wolves Uniformed- territory- penguins Random- scavengers Population size Birth Death Immigration Emigration Stable= B+I= D+E Growth=(B-D) + (I+E)> 0 Declining= B+ I < D + E Sex ratio- 1 to 1 How many females to males Generation time Age Age structure Survivorship curve and invasive species Demography Factors that affect growth and decline of populations Vital stats and how they change Belding ground squirrels 1- High death rate in post reproductive years- Humans, whales 2- Constant mortality rate throughout life span- Birds, hydra 3- Very high early mortality but the few survivors live long- oyster, sea turtles PARENTAL INVESTMENT K selected species -late reproduction - few offspring - Invest in a lot in raising - Coconut, primates R selected species Early reproduction Many offspring Little parental care K=Type 1 R=type 2 Kestrel Falcons- The cost of larger broods to both male and female parents Large brood size is bad Exponential growth rate Characteristic of population without limiting factors Introduced to a new environment or rebounding from a catastrophe Introduced species Non native species Transplanted populations grow exponentially in new are Out compete native species Loss of natural controls Lack of predators, parasites, competitors Reduce diversity Examples Afro honey bee Gypsy moths zebra s Mussel Filter feeders Toxins bioaccumulate to birdies and such Invasive species and carrying capacity Lamprey- sucky sucky Carrying capacity- Maximum population size that can support with no degradation of habitat Measuring population density Individuals in a population? Niche An organism’s niche is its ecological role Competitive Exclusion No too similar species can occupy the same niche Resource partitioning Interspecific relationships- symbiotic interactions -competition(-/-), compete for limited resources -predation/parasitism(-/+) -mutualism(+/+), ex. lichens (algae and fungus) -commensalism(+/0), ex. barnacles attached to whale Mimicry Batesian mimicry- harmless species mimics a harmful model King snake is harmless while coral snake is Mullerian mimicry- two or more protected species look like each other, “group mentality”, group defense, usually they are both toxic or poisonous, ex. Cuckoo bee and yellow jacket Keystone species and ecological succession Aposematic- warnings, species come to resemble each other Species diversity- how many diff species Composition- dominant species Most biomass are chemosynthetic bacteria But mostly producers Keystone species Influential ecological role Exert important regulating effects Keystone species increases diversity AMERICAN BEAVER Ecological succession is recovery Pioneer species Secondary succession- Existing community cleared KEELING CURVE- Bonus Animal behavior- Innate vs learned Animal behavior Fixed action patterns and imprinting Behavior- Movement Pheromones Electricity Behavior- everything an animal does and how it does it Innate- inherited, instinctive Automatic No learning curve Learned Ability to learn is inherited, but the behavior during animals lifetime Variable and flexible Proximate causes Immediate stimulus and mechanism How and what questions Ultimate causes Evolutionary significance How does behavior contribute to survival Proximate is what Ultimate is why ETHOLOGY Pioneers in the study of animal behavior Karl von Frisch- The Waggle Dance NIko Tinbergen Konrad Lorenz Fixed Action pattern (FAP) Sequence of behavior essentially unchangeable and usually conducted to completion once started Sign stimulus Supernormal stimulus Responding more to a larger sign stimulus Some birds like fake eggs Taxis6 Change in direction Automatic movement towards or away from a stimulus Phototaxis Chemotaxis Kinesis Change in rate of movement in response to stimulus Migration is complex innate behavior Magnetite Associative learning- learning to associate a stim with a consequence Operant conditioning- trial and error learning Skinner box Habituation: loss of response to stimulus ¨cry wolf¨ Decrease in response to repeated occurrences of stimulus Enables animals to disregard unimportant stimuli Example: the lion and the leaves, iguana and waves, and marmot with humans Social behaviors Communication by song Bird song- species identification and mating ritual Mixed learned and innate Insect song Mating ritual and song innate 2. Agonistic behaviors Threatening and submissive ritual HFPHJF