Yumi's Grade 11 Biology Exam Notes PDF

Grade 11 University Biology 2 Unit 1 - Plants: Structure and Function...........................................................................

Grade 11 University Biology 2 Unit 1 - Plants: Structure and Function.....................................................................................................8 Introduction to Plants:............................................................................................................................. 9 Five Plant Characteristics..................................................................................................................9 Adapting on land - (Earliest organisms: Plant-like protists lived in water)...................................... 9 Non-vascular Plants.......................................................................................................................... 9 Vascular Plants.................................................................................................................................. 9 Seed Producing Plants.......................................................................................................................9 Flowering Plants............................................................................................................................... 9 Monocots, Dicots and Vascular Bundles:.............................................................................................. 10 Monocotyledons..............................................................................................................................10 Dicotyledons................................................................................................................................... 10 Vascular Bundles.............................................................................................................................10 Xylem..............................................................................................................................................10 Phloem............................................................................................................................................ 10 Roots and Stems:................................................................................................................................... 11 Roots................................................................................................................................................11 Two Root Types...............................................................................................................................11 Four Functions.................................................................................................................................11 4 Zones............................................................................................................................................ 11 Stems............................................................................................................................................... 11 Two Stem Types.............................................................................................................................. 11 Four Functions.................................................................................................................................11 Leaves:...................................................................................................................................................12 Four Functions................................................................................................................................ 12 Deciduous Leaves/Needles............................................................................................................. 12 Leaf Structure..................................................................................................................................12 Plant Tissues:......................................................................................................................................... 13 Plant Growth................................................................................................................................... 13 Plant Tissues....................................................................................................................................13 Dermal Tissue (Example: Leaves).................................................................................................. 13 Ground Tissue - 3 Types................................................................................................................. 13 Bonus - Meristems (2 Types).......................................................................................................... 13 Transport of Water and Minerals in Xylem........................................................................................... 14 Transpiration - Cohesion - Adhesion - Tension theory of water movement................................... 14 Transpiration................................................................................................................................... 14 Behaviour of Water- Hydrogen bonding.........................................................................................14 Plant Hormones..................................................................................................................................... 15 Plant cells send signals for:............................................................................................................. 15 Four major classes...........................................................................................................................15 Plant Tropism - Plant grows response to stimuli in environment................................................... 15 3 Seed Growth and Development............................................................................................................. 16 Structure of Mature Seed................................................................................................................ 16 Seed Development.......................................................................................................................... 16 Dormancy - Dormant period last many years................................................................................. 16 Germination.................................................................................................................................... 16 Support............................................................................................................................................ 16 Seed Adaptations - Seed Dispersal................................................................................................. 16 Unit 2: Genetic Processes 2A.....................................................................................................................17 Introduction to Genetics - V3................................................................................................................ 18 Genetics and Inheritance................................................................................................................. 18 DNA and Chromosomes................................................................................................................. 18 Genes and Traits..............................................................................................................................18 Haploid and Diploid Cells...............................................................................................................18 Vocab...............................................................................................................................................18 Cell Cycle and Meiosis..........................................................................................................................19 Interphase Step 1: Growth 1............................................................................................................19 Interphase Step 2: Synthesis........................................................................................................... 19 Interphase Step 3: Growth 3............................................................................................................19 Mitosis.............................................................................................................................................19 Cytokinesis......................................................................................................................................19 DNA Structure....................................................................................................................................... 20 DNA, Nucleotides and Antiparallel Strands................................................................................... 20 Nucleotide (base of nucleic acid)....................................................................................................20 Developing DNA Model................................................................................................................. 20 Karyotype.............................................................................................................................................. 20 Summary - (Before fertilization).....................................................................................................20 Meiosis...................................................................................................................................................21 Review of Chromosome Patterns....................................................................................................21 Meiosis............................................................................................................................................ 21 Meiosis Stages.................................................................................................................................21 Meiosis Forms Gametes..................................................................................................................21 Gametogenesis, Genetic Variation and Mutations.................................................................................22 Gametogenesis................................................................................................................................ 22 Genetic Variation.............................................................................................................................22 Independent Assortment................................................................................................................. 22 Crossing over.................................................................................................................................. 22 Non-disjuction Chromosomal Mutations........................................................................................22 Structural Chromosomal Mutations................................................................................................ 22 4 Unit 2B: Inheritance Patterns Unit 2B.....................................................................................................23 Mendelian Genetics Terminology..........................................................................................................24 Vocab...............................................................................................................................................24 Alleles............................................................................................................................................. 24 Phenotype and Genotype................................................................................................................ 24 Mendel’s Laws.......................................................................................................................................24 1) Law of Segregation.....................................................................................................................24 2) Law of Independent Assortment.................................................................................................24 Monohybrid Crosses..............................................................................................................................25 Generations..................................................................................................................................... 25 Fertilization..................................................................................................................................... 25 Medel’s Observations......................................................................................................................25 Punnett Squares...............................................................................................................................25 Test Crosses.....................................................................................................................................25 Dihybrid Crosses................................................................................................................................... 25 Steps for dihybrid cross...................................................................................................................25 Co-dominance, Incomplete Dominance, Sex Linkage.......................................................................... 26 Incomplete Dominance................................................................................................................... 26 Codominance.................................................................................................................................. 26 Sex Linkage.....................................................................................................................................26 Multiple Alleles, Polygenetic Inheritance............................................................................................. 27 Combinations.................................................................................................................................. 27 Genes and Immune system............................................................................................................. 27 Human Blood Groups..................................................................................................................... 27 ABO System................................................................................................................................... 27 Blood Types/Blood Transfusions...........................................................................................................27 Note:................................................................................................................................................27 Simple Patterns of Inheritance & Pedigrees.......................................................................................... 28 Simple Inheritance Patterns............................................................................................................ 28 Pedigrees......................................................................................................................................... 28 Autosomal Dominant Inheritance Pattern.......................................................................................28 Autosomal Recessive Inheritance Pattern.......................................................................................28 Unit 3: Diversity of Living Things Unit....................................................................................................29 Taxonomy - Classification of Living Organisms...................................................................................30 Taxonomy - How closely related.................................................................................................... 30 Three Types of Evidence.................................................................................................................30 Domain............................................................................................................................................30 Kingdom..........................................................................................................................................30 Dichotomous Keys................................................................................................................................ 31 Determining Species....................................................................................................................... 31 5 Binomial Nomenclature.................................................................................................................. 31 Prokaryotic/Eukaryotic Cells Compared............................................................................................... 31 Virus: Living or Not.............................................................................................................................. 32 Physical Structure........................................................................................................................... 32 Virus Goal → Reproduce................................................................................................................ 32 Helpful Viruses................................................................................................................................32 Lytic Cycle: Viral Reproduction..................................................................................................... 32 Sneaky Viruses - Some are lysogenic - Stay long time...................................................................32 Unit 4: Evolution........................................................................................................................................ 33 Introduction to Evolution.......................................................................................................................34 Biological Evolution....................................................................................................................... 34 Microevolution................................................................................................................................34 Macroevolution............................................................................................................................... 34 Darwin and the Theory of Evolution..................................................................................................... 35 Scientific Contributions to Theory of Evolution................................................................................... 36 Pre-Darwinian Times...................................................................................................................... 36 Evidence for Evolution.......................................................................................................................... 37 Biological evolution........................................................................................................................ 37 5 Main Categories of Evidence for Theory of Evolution:...............................................................37 1) Biogeography..............................................................................................................................37 2) Fossil Record.............................................................................................................................. 37 3) Anatomy Homologous Structures...............................................................................................37 4) Comparative Embryology...........................................................................................................37 5) Molecular Biology...................................................................................................................... 37 Evolutionary Adaptations...................................................................................................................... 38 Adaptation - enhances organism's fitness, increases chance of survival/successful reproduction. 38 Evolution of Complex Adaptations:............................................................................................... 38 1) Structural Adaptations:............................................................................................................... 38 2) Physiological Adaptations:......................................................................................................... 38 3) Behavioural Adaptations:........................................................................................................... 38 5 Mechanisms affecting populations; microevolution/changes to allele frequencies in population... 39 1) Mutations.................................................................................................................................... 39 2) Genetic Drift............................................................................................................................... 39 3) Gene Flow...................................................................................................................................39 4) Non-random Mating................................................................................................................... 39 5) Natural Selection........................................................................................................................ 39 Mechanisms of Microevolution - Natural/Sexual Selection..................................................................40 Darwin’s 5 points → Natural Selection Conditions........................................................................40 4 Types of Natural Selection........................................................................................................... 40 6 1) Directional Selection.................................................................................................................. 40 2) Stabilizing Selection................................................................................................................... 40 3) Disruptive Selection....................................................................................................................40 4) Sexual Selection..........................................................................................................................40 Macro-evolution - Speciation................................................................................................................ 41 Two main paths by speciation......................................................................................................... 41 Reproductive isolation.................................................................................................................... 41 Two mechanisms.............................................................................................................................41 Six types of pre-zygotic barriers:.................................................................................................... 41 Two types of post-zygotic barriers:.................................................................................................41 Two processes which divergent speciation occurs:.........................................................................41 Evolution Occurs in Patterns................................................................................................................. 42 4 Major types:................................................................................................................................. 42 1) Divergent Evolution....................................................................................................................42 2) Convergent evolution..................................................................................................................42 3) Coevolution.................................................................................................................................42 4) Extinction....................................................................................................................................42 Rate of Evolutionary Change.......................................................................................................... 42 Unit 5: Internal Systems: Structure and Function..................................................................................43 Introduction to Internal Body Systems.................................................................................................. 44 Organisms....................................................................................................................................... 44 Tissues.............................................................................................................................................44 Organ...............................................................................................................................................44 Organ System.................................................................................................................................. 44 Anatomy..........................................................................................................................................44 Physiology.......................................................................................................................................44 Human Digestive System...................................................................................................................... 45 Parts of Digestive System............................................................................................................... 45 Accessory Organs............................................................................................................................46 Mechanical/Chemical Digestion............................................................................................................47 Steps for digestion:..........................................................................................................................47 Food Polymers................................................................................................................................ 47 Enzymes.......................................................................................................................................... 47 Carbohydrates................................................................................................................................. 47 Proteins............................................................................................................................................47 Lipids.............................................................................................................................................. 47 Introduction to Respiratory System....................................................................................................... 48 Upper Respiratory System Structures............................................................................................. 48 Lower Respiratory System Structures.............................................................................................48 Human Respiration................................................................................................................................ 49 7 Fours main steps..............................................................................................................................49 Structures of Mammalian Circulatory System...................................................................................... 50 Three Main Structures.....................................................................................................................50 3 Major Cycles/Loops..................................................................................................................... 50 Three Types of Blood Vessels......................................................................................................... 50 Blood............................................................................................................................................... 50 The Heart - Structure and Function....................................................................................................... 51 Heart Structure................................................................................................................................ 51 Co-ordination of Heartbeat............................................................................................................. 51 Three Steps to Heartbeat................................................................................................................. 51 Blood Pressure................................................................................................................................ 51 Normal blood pressure.................................................................................................................... 51 8 Unit 1 - Plants: Structure and Function 9 Introduction to Plants: Five Plant Characteristics Multicellular eukaryotes Autotrophs; chloroplasts for photosynthesis Non-motile Cell walls made of cellulose Responds to environment Adapting on land - (Earliest organisms: Plant-like protists lived in water) Protective for leaves and stems not drying out System of vessels transporting water, nutrients and wastes in roots stems and leaves Capturing energy from light by using stems and leaves a system to hold up plant Non-vascular Plants No system of vessels Mosses, liverworts and hornworts evolved from green algae 500 mya Need moist surface to swim together for reproduction Lack true leaves, roots or stems All water, nutrients and waste move between cells by osmosis and diffusion Growth is limited Make spores not seeds Vascular Plants Vascular tissue or vessels transports materials between different parts of plan Has true roots to anchor them and absorb water and minerals Photosynthetic and absorb gases from atmosphere Spores reproduction Seed Producing Plants Have seeds to improve reproductive success Reproduce sexually without water Seeds contain fully developed embryo: food supply and water-proof seed coat Gymnosperms produce naked seeds: cones Flowering Plants Produce flowers to improve reproductive success Angiosperms produce flowers (Monocot and dicots) Protect fruit, attract animals to distribute seeds Pollen fertilizes ovary that develops into fruit surrounding and protecting seeds 10 Monocots, Dicots and Vascular Bundles: Monocotyledons Herbaceous/soft-stemmed: Orchids, grasses, wheat, and rice Woody/Tough stemmed: Bamboo, palms and sugar cane Dicotyledons Herbaceous/soft-stemmed: Potatoes, squash, salad greens and legumes Woody/Tough stemmed: Trees and shrubs - maples, oaks and roses Angiosperms - same plant parts, vascular bundle patterns different - affect roots, stems, leaves Vascular Bundles 2 types of vessels - Xylem and Phloem Xylem FLong tracheids that are dead cells Water and minerals from soil into roots by osmosis Water evaporates from leaves by transpiration Carried up the stems from roots to leaves and flowers Phloem Sieve tube elements that are living cells Sugar water carried up and down by translocation Carries sugar between plant cells Monocots Dicots Seeds Single cotyledon Two cotyledons Leaves Parallel veins Branched veins Flowers Petals multiples of 3 Petals multiples of 4 or 5 Stems Scattered vascular bundles Ring-like vascular bundles Roots Fibrous roots Taproot 11 Roots and Stems: Roots Two Root Types Monocot - Fibrous and networked Dicot - Tap roots Four Functions Anchors the plant Absorb water and minerals from soil through osmosis Protect soil from erosion Xylem carry water up to plant 4 Zones Maturation - Root hairs, xylem, phloem Elongation - Allows root to deepen which soil Meristematic region - Cell production Root Cap - Protects meristematic region Root hairs - Extensions of epidermis, greatly increase surface area Stems Two Stem Types Monocot - Scattered vascular tissue Dicot - Outer ring vascular tissue Annual - Must grow from seed every year, green stems Perennial - Grow once, keeps growing, wooden stems Four Functions Hold leaves up to light Transport water and dissolved minerals in xylem Transport dissolved sugar in phloem Specialized stems Stolons - Strawberries have runners for asexual reproduction Rhizomes - Irises have underground stem buds for asexual reproduction Tubers - Starch storage like potatoes 12 Leaves: Four Functions Trap light energy for photosynthesis and produce glucose for cellular respiration Gas exchange (CO2 and O2) Water lost by transpiration by leaves Provide food, shade, habitat and oxygen Formula photosynthesis - 6CO2 + 6H2O → C6H12O6 + 6O2 Deciduous Leaves/Needles Deciduous - wide to capture light energy, flat for surface area for gas exchange by diffusion Needles - Thick/waxy coat saves water, photosynthesis all year, low wind resistance Leaf Structure Cuticle - Waxy layer protect leaf and reduce water and gas loss Epidermis - Provide strength, transparent for sunlight, a cell layer thick, low; stomata/guard cells Palisade Cells - Under epidermis, large numbers of chloroplasts with chlorophyll, main site of photosynthesis, long box for light enter at top, gases diffuse in/out at bottom Stomata/Guard Cells - Small hole at bottom, designed for gas exchange, water transpire out Spongy Mesophyll - Loosely packed cells near bottom, large air spaces for gases to diffuse, water vapour move into spaces between cells and escape through stomata Vascular bundles - Found in veins of leaf Xylem - Water up to all plant cells, minerals up to all leaf cells Phloem - Carries glucose from leaf out to other plant cells 13 Plant Tissues: Plant Growth Primary - Results of plant length, apical growth, entire growth for 1st year of life Secondary - Results of increased diameter, lateral in second/subsequent years of life Plant Tissues Plant anatomy contains specialized tissue for: Absorption, Transport, Storage, Photosynthesis, Reproduction 3 Types: Epidermal/Dermal, Vascular, Ground Dermal Tissue (Example: Leaves) Outer protective covering Epidermis experience primary growth, replaced by periderm in secondary growth Cells are tightly packed Many Plants have trichomes/hairs Many forms, all plant parts Function: Absorption, protection, secretion Ground Tissue - 3 Types Makes up bulk Fills space between dermal and vascular tissue Contains most of internal, nonvascular regions Parenchyma - (Parent - Holds together with cell wall) Thin, flexible cell wall Large vacuoles Only cells that engage in mitosis Filled with chloroplasts, chlorenchyma Collenchyma - (Celery - Uneven thick walls) Thickened cell walls, unevenly thick Provide support/plasticity in stems/leaves during rapid growth Alive at maturity, like parenchyma Sclerenchyma - (Second - secondary cell wall) Thick support Dead at maturity, shells of nuts and spine of cacti Bonus - Meristems (2 Types) Apical - Regions at root and shoot tips, begin within seeds once germinate - divide and elongate Lateral - Regions other, for complete/incomplete tissue within roots/stems, diameter growth 14 Transport of Water and Minerals in Xylem Transpiration - Cohesion - Adhesion - Tension theory of water movement Transpiration Water vapour concentration higher inside leaf than outside, water diffuses out of leaf through stomata Creates tension in mesophyll, draws water from xylem of nearest vein into extracellular space surrounding mesophyll cells Remove water from veins, establish water tension in xylem, column drawn up from root Behaviour of Water- Hydrogen bonding Results in cohesion (sticking of molecules together) Narrower tube, greater the tension water column can stand Maintenance of water column occurs through adhesion of water to walls of tube Does not require energy Water moves passively toward a more negative water potential region Transpiration contributes to plant’s temperature regulation 15 Plant Hormones Hormones are chemicals that travel throughout plant causing target cells to respond: Controls - plant growth or development, plant responses to environment Plant cells send signals for: Trees to drop leaves Start new growth Fruit to ripen Flowers to bloom Seeds to sprout Four major classes Gibberellins Promote embryo growth, development of vascular tissue, stem growth Cytokinins Promote cell division, cell differentiation, delay aging of fruit and leaves Ethylene Fruit tissues, fruits ripen, produce more ethylene, accelerating ripening process Abscisic Acid Mainly made in mature leaves, block growth hormones, Inhibits growth of: germinating seeds, growth of buds, plant stems Auxin In stem tip promoting cell elongation, move to darker side, tip to lighter side Plant Tropism - Plant grows response to stimuli in environment Phototropism Response to light, bends towards light Geotropism Response to gravity, grow down with gravity, shoots up against gravity Thigmotropism Response to touch, vines wrap around trees 16 Seed Growth and Development Seeds - Flowers responsible for protect and distribute, embryo sac form seed coat and fruit Structure of Mature Seed Testa/Seed Coat - Protects seed Endosperm - Tissue providing starch for embryo Epicotyl - Above cotyledon; creates shoots/leaves Hypocotyl - Below cotyledon; creates roots Micropyle - Water opening Embryo/cotyledon Hilum/radicle - “eye” of seed, grows root from radicle Seed Development Embryo slowly forms roots and shoot Monocot; single cotyledon, Dicot; double cotyledon Cotyledon - contain all, or additional nutrient-rich material called endosperm Dormancy - Dormant period last many years Slow biological activity - metabolism falls, dehydration, vacuoles deflate, food hardened Contains living embryo Protected by seed coat Germinate when appropriate temperature and moisture Germination Seed/Coat absorb water, embryo grows Seed coat ruptures; root/shoot emerge Root grows downward, shoot upward Growth due to certain chemicals/effect of gravity Support Cotyledons raised out of soil photosynthesis to produce food and energy Cotyledons buried support development until plant support itself Seed Adaptations - Seed Dispersal Fruit - Both digested and undigested, some don’t germinate till passed through Animal Helpers - Seed-Eating Rodents; squirrels hide and bury acorns Flight - Explode when mature from pods or fruits Wing-like structure for flight, Water plants create air pocket for float and disperse 17 Unit 2: Genetic Processes 2A 18 Introduction to Genetics - V3 Genetics and Inheritance Passed from generation to generation Sexually reproducing, inheritance traits determine genetic variation, for evolution DNA and Chromosomes DNA is identical to all plants/animals Order of Nitrogen bases in DNA makes organisms unique, double helix shape Chromosomes; coiled DNA, deoxyribonucleic; huge molecule, carries genetic info Genes and Traits Gene; Short segment of DNA control expression of trait Instruction to make protein; form all cell structures and enzymes Hormones are proteins, critical transporting material across membranes Genetic traits controlled by one gene, body shape controlled by many genes Haploid and Diploid Cells Somatic/Human Body - 46 chromosomes/23 pairs, diploid, 2 copies, mitosis Gametes/Sex cells - Ovaries/Testes, 23 chromosome, haploid, 1 copy, meiosis Vocab - Autosomes; First 22 pairs of chromosomes - Sex chromosomes; 23rd pair of chromosomes - Somatic cells; Every cell except sperm and egg - Tetrad; Pairs of corresponding HoC - Polar bodies; provide nutrients to egg, carries excess genetic info 19 Cell Cycle and Meiosis Cell Cycle and Interphase Interphase (G1, S, G2; growing and replicating chromosomes) Mitosis and Cytokinesis Interphase Step 1: Growth 1 Makes new molecules, grows larger, new long or short depending on type/health Interphase Step 2: Synthesis More DNA, chromatin; uncoiled chromosomes replicated/duplicated Forms double stranded, sister chromatids; same genes, centromere Interphase Step 3: Growth 3 More molecules and grows larger Mitosis Short part, sister chromatids evenly divide, opposite ends, growth/repair tissue Prophase, Metaphase, Anaphase, Telophase Cytokinesis Divides all cytoplasm/organelles, forms new cell membranes 20 DNA Structure DNA, Nucleotides and Antiparallel Strands Deoxyribonucleic acid DNA make genetic instructions for cell parts and functions 1953, James Watson, Francis Crick, developed double helix DNA 2 strands of nucleic acids Antiparallel 2 nucleic acid strands held by hydrogen bond between nitrogen bases Rule: Complementary base pairing; Adenine - Thymine, Cytosine - Guanine Nucleotide (base of nucleic acid) Sugar Phosphate group One of four nitrogen bases; Adenine (A), Guanine (G), Cytosine (C), Thymine (T) Developing DNA Model Resalind Franklin; x-ray crystallography were two antiparallel sugar phosphate backbone Watson/Crick built double helix models Karyotype - Picture of particular set of chromosomes, diagnose genetic disorders - Gene; part of chromosome, control particular trait, Allele; variation of gene - Homologous; pairs of chromosomes identical in length, alleles found same gene HoC n - number of haploid chromosomes in organism Summary - (Before fertilization) - Haploid; Unreplicated (n) (example) - Diploid; Unreplicated (2n) (In interphase) - Diploid; Replicated (4n) (Before metaphase) 21 Meiosis Review of Chromosome Patterns End of mitosis’ telophase has unreplicated copy, interphase; uncoil to chromatin/replicate Meiosis How sex cells/gametes are made; gametogenesis Number of chromosomes is reduced by half, haploid make diploid zygote Meiosis I; reduction division, one diploid → 2 haploid; separate HoC Meiosis II; haploid cell divide → separating sister chromatids Meiosis Stages Prophase I - Nuclear membrane dissolve, centrioles move, 4 sister chromatids form tetrad Metaphase I - Tetrad line (2x) at equatorial plate, spindle fibres from centrioles to centromeres Anaphase I - Spindle fibre pull HoC to opposite ends, reduction division Telophase I - Nuclear membranes might reform, cytoplasm divide into haploid daughter cells Prophase II - Centrioles replicated, move opposite poles, new spindle fibres attach Metaphase II - Single line equatorial plate Anaphase II - Spindle fibres separate sister chromatids, move to opposite ends Telophase II - Cytoplasm separates, four haploid cells Meiosis Forms Gametes Males; spermatogenesis form four sperm cells Female; Oogenesis form one egg, three polar bodies (not used for reproduction) 1 egg cell (all Cytoplasm), 3 polar bodies; only haploid copy of chromosomes Mitosis Meiosis Starting # cells 1 diploid 1 diploid Where Body or somatic cells Ovary or testes Ending cells Genetically identical Genetically different Ending # cells 2 4 End cells 2n n Haploid or diploid Diploid Haploid Cycle Yes No 22 Gametogenesis, Genetic Variation and Mutations Gametogenesis Spermatogenesis - Male form sperm, diploid primary spermatogonia form two haploid secondary spermatocytes, form four haploid sperm Oogenesis - Diploid oogonium germ cell form ovum/two or three haploid polar bodies Fertilization - Haploid sperm enters haploid egg, form diploid zygote, first somatic cell Genetic Variation Four methods increasing genetic variation: - Independent Assortment - Crossing Over - Non-disjunction Chromosomal Mutations - Structural Chromosomal Mutations Independent Assortment Chromosomes segregate independently, beneficial to sexually reproducing organisms, increase genetic variation in gametes Crossing over Occurs meiosis prophase I, homologous chromosomes overlap/exchange portions of chromatids Non-disjuction Chromosomal Mutations Pairs don’t separate properly during anaphase I Sister chromatids don’t separate during anaphase II Monosomy (missing) Trisomy (extra) Polyploidy (extra sets, mainly plants) Structural Chromosomal Mutations Crossing over fail in meiosis I Deletion (Removal segment) Duplication (Repeats segment) Inversion (Reversal) Translocation (movement segment to non-homologous chromosome) 23 Unit 2B: Inheritance Patterns Unit 2B 24 Mendelian Genetics Terminology Vocab - Hereditary; Passed down - Polygenetic; more than one origin/source - Agglutination; clots/clumps - Monozygotic twin; twins where exact same genetic information - Dizygotic twin; twins fertilized by two separate sperm cells Alleles - Alternate form of genes - Dominant; hereditary trait, always expressed/seen - Recessive; hereditary factor, not usually expressed - Homologous Dominant (TT), Homologous Recessive (tt), Heterozygous (Tt) - TT/tt; purebred Phenotype and Genotype - Genotype; genetic makeup of organism - Phenotype; Particular physical appearance Mendel’s Laws 1) Law of Segregation a) Inherited traits are determined by pairs of genes b) Each genes separated into separate gametes 2) Law of Independent Assortment a) Inheritance of one trait NO affect inheritance of another trait’s allele b) Homologous chromosomes randomly line up on the equator and then separate 25 Monohybrid Crosses Generations 1) First generation; parent/P1 2) P1/parent’s offspring; first filial/F1 3) F1/first filial’s offspring; second filial/F2 Fertilization - Cross fertilization; pollen fertilizes different plant - Self-fertilization; pollen fertilizes same plant Medel’s Observations - When dominant/recessive alleles both present, only dominant expressed - Each pair of alleles segregates meiosis, formation of sex cells - Each parent contributes one allele during fertilization → gametes are haploid - Pure-bred plant self-fertilizes, all offspring receive identical allele copies Punnett Squares 1) Show parent alleles 2) Show possible genotypes for offspring 3) Ratio of phenotypes/genotypes Test Crosses - Determine genotype of individual showing dominant trait Dihybrid Crosses - Made when phenotypes/genotypes with TWO independent alleles are analysed - Both heterozygous gametes gives phenotype 9:3:3:1 ratio Steps for dihybrid cross 1) Determine gametes using FOIL 2) Determine offspring genotypes by crossing parent gametes 3) Ratio of phenotypes/genotypes 26 Co-dominance, Incomplete Dominance, Sex Linkage Incomplete Dominance - When two alleles are equally dominant, heterozygous produce new phenotype - Mixed of both alleles - A capital letter used for both dominant/recessive, difference showed as “exponent” Codominance - Both alleles expressed at same time - Combination of both alleles - A capital letter used for both dominant/recessive, difference showed as “exponent” Sex Linkage - Genes located on sex chromosomes - X-chromosome much larger, more genes than Y-chromosome - If sex linked trait is recessive - Female only express if homozygous recessive - Male will express if from mother, none from father - Sex linked showed with X, different showed as “exponent”, and Y (for males) 27 Multiple Alleles, Polygenetic Inheritance Combinations - Di-allelic genes make 3 genotypes (AA, Aa, aa) - Genes with 3 alleles make 6 genotypes - Genes with 4 alleles make 10 genotypes - Genes with 8 alleles make 36 genotypes Genes and Immune system - Poly-allelic genes associated with tissue types - Varied genes important for immune system Human Blood Groups - A single determines ABO blood type (Type A, B, AB, O) - Responsible determining type of antigen protein, attached to red blood cell’s membrane - Antigen protein; molecule that stimulates immune system ABO System - Shown by I, IA make antigen A, Type IB make antigen B, i make no antigen - Alleles are representative of antigens on surface of red blood cells - Type A/B codominant, Type O is recessive Blood Types/Blood Transfusions - Immune system recognizes own blood type → self, other blood types → non-self - If incompatible, will result in agglutination of foreign red blood cells - None will agglutinate Type O; carries no antigen, pass as incognito Note: - Type O → Universal donor - Type AB → Universal recipient 28 Simple Patterns of Inheritance & Pedigrees Simple Inheritance Patterns - Autosomes; chromosomes other than sex-chromosomes - Autosomal Inheritance; traits whose genes on chromosomes 1-22 - Autosomal dominant; trait occurs has one or both copies - Autosomal recessive; trait occurs if has both copies Pedigrees 1) Determine Inheritance 2) Let Statements 3) Fill in Pedigree Autosomal Dominant Inheritance Pattern 1) All affected individuals have affect parent 2) Approx. 50% is affected 3) Males/Females are equally likely affected 4) Unaffected children have unaffected offspring 5) Affected should always assume heterozygotes unless otherwise 6) Phenotype appears every generation Autosomal Recessive Inheritance Pattern 1) Males/Females equally affected 2) Affected individual may have unaffected parents 3) All offspring of two affected 4) Phenotype may skip generation X-linked Recessive Inheritance Pattern 1) Tait is never passed from father to son 2) Males more likely affected than females 3) Treat/disease passed from affected grandfather → carrier daughters → half of grandsons 29 Unit 3: Diversity of Living Things Unit 30 Taxonomy - Classification of Living Organisms Taxonomy - How closely related - Classifying groups of organisms based on characteristics - Developed by Carolus Linneaus in 1700s (based on physical characteristics) - Now also genetic and biochemical info - Order → Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species - Species → Individuals that can interbreed, produce fertile offspring Three Types of Evidence 1) Anatomical evidence - Structures are the same 2) Physiological evidence - Proteins/enzymes work the same 3) DNA evidence - Genetically close are genes and proteins Domain - Domain → Bacteria, Archaea, Eukarya - Based on two types of cells → Prokaryotes, eukaryotes - Bacteria/Archaea → Prokaryote cells; lack nucleus and membrane bound organelle, small - Eukarya → Eukaryote Cells; Nuclear membrane protect DNA, organelles Kingdom - Kingdom → Bacteria, Archaea, Protista, Plantae, Animalia, Fungi - Cell types, number of cells, cell wall material, nutrition, reproduction Domain Bacteria Archaea Eukarya Kingdom Bacteria Archaea Protista Plantae Fungi Animalia Example Staphylococcus Sulfolobus Amoeba Maple Tree Mushroom Rabbit archaea # of Unicellular Unicellular Unicellular/ Multicellular Mostly Multicellular Cells Multicellular Multicellula r Cell Wall Peptidoglycan No cell Cellulose/ Cellulose Chitin No cell Material wall no cell wall wall Nutrition Autotrophs/ Autotroph/ Autotroph/ Autotroph Heterotroph Heterotroph Heterotroph Heterotroph Heterotroph Reproduce Asexual Asexual Asexual/ Sexual Sexual Sexual Sexual 31 Dichotomous Keys Determining Species 1) Biological species concept - Successfully breed/produce fertile offspring a) Only for living, sexually reproducing organisms 2) Morphological species concept - Comparing measurements/physically descriptions a) Often for plants, asexually reproducing organisms 3) Phylogenetic species concept - Evolutionary relationships between organisms a) based on DNA studies or fossil evidence Can be show as branching tree diagram, questions start with: 1) Is it multicellular? 2) Does it have tissues 3) Radial symmetry? (Multiple planes identical, ex. Starfish) 4) Bilateral symmetry? (Single plane identical, ex. Cat) Binomial Nomenclature Carolus Linnaeus developed binomial naming system 1) Scientific name consists of genus and species 2) Both words italicized or underlined 3) Genus always capitalized 4) Species always lowercase 5) Both name in Latin 6) Species name must be unique in same Genus Prokaryotic/Eukaryotic Cells Compared Billions of Years Ago Action 4.5 Formation of Earth 3.5 First Prokaryotic Cells 2.5 First Cyanobacteria 1-1.25 First Eukaryotic Cells Classification of organisms based on similarities/differences Cell structure/organization, nutrition, and reproduction → dichotomous key questions 32 Virus: Living or Not - Have nucleic acids/reproduce (inside host) - No have cells - Cannot make proteins - Cannot use energy - Simple group of chemicals (without host), not alive - Not cellular - Cannot grow/develop on it's own - Infect; anything cellular; plants, animals, bacteria - BUT infect very specific Physical Structure Two main components - Capsid; Protein coat, protects virus, outside of virus - Genetic material (RNA/DNA), inside virus - Summary → core of nucleic acid, surrounded by capsid, made up of RNA or DNA Virus Goal → Reproduce 1) Invades cell 2) Gets its DNA into cell 3) Takes over 4) Makes proteins/nucleic acids 5) Assembly of newly synthesized virus particles Helpful Viruses - Used to attack diseases causing bacteria - Bacteriophages; destroy bacteria, not human cells - Insert good genes into people with genetic diseases - Introduce desired traits Lytic Cycle: Viral Reproduction 1) Attach to cell surface, chemically recognizes host 2) Makes proteins/nucleic acids with host’s cells 3) New virus assembled 4) Release new virus particles into infected cell Sneaky Viruses - Some are lysogenic - Stay long time - Insert genome into host cell, long periods of time - May switch to lytic cycle 33 Unit 4: Evolution 34 Introduction to Evolution Biological Evolution - Genetic change in a population of organism over time Microevolution - genetic changes over small number of evolutions, within a species - Natural selection of fittest offspring → adaptation - Changes in allele frequencies, better adapt, happen in a few generations Macroevolution - Change on large scale, takes centuries or millennia - Evolution between species, documented in fossil records - Many small changes or mutations → new designs/developments - Can lead to extinction/rise of new species Numerous micro-evolutionary changes can eventually result in new species by maco-evolution 35 Darwin and the Theory of Evolution Darwin’s Observations 1) Rodents in SA look alike, different from European rodents 2) Fossilized glyptodont → modern armadillo 3) Tortoises, finches, plants on Galapagos looked like nearest mainland 4) Each Galapagos finch specialized in different food, beak size, shape 5) Traits passed from parents to offspring, much genetic variation in offspring Organisms gradually develop and change into more complex organisms Thomas Malthus’s proposal → populations produced far more offspring than resources - Competition for food, water, space → weakness, starvation, death by disease Natural Selection → Only offspring fittest for environment would survive and reproduce Populations underwent descent with modification due to natural selection, explain evolution: 1) Offspring produce more offspring than can survive; competition for resources 2) A lot of genetic variation in a population, variation can be inherited 3) Better suited more likely to survive/reproduce 4) Evolutionary change slow, gradual process Scientific theory → Explanation of large concept pulling together many related observations 36 Scientific Contributions to Theory of Evolution Pre-Darwinian Times Aristotle (circa 400 BCE) - Believe in Natura (Scale of Nature), arrange on scale more complex, no evolution/change Carolus Linnaeus (1707-1778) - Binomial nomenclature system of taxonomy Georges-Louis Leclerc de Buffon (1707-1788) - One of first to challenge evolution, Earth may be over 6000 years George Cuvier (1768-1832) - Paleontologist, rocks depper had much different fossils than present, no evolution - catastrophism; Earth was a place catastrophes happened, different animals emerged James Hutton (1726-1797) - Gradualism; geological changes are slow/gradual, long periods of time Charles Lyell (1797-1875) - Uniformitarianism; geological processes have not changed Jean Baptiste Lamarck (1744-1829) 1) Use/disuse - parts of body used regular basis become larger/stronger, not used deteriorate 2) Inheritance of acquired characteristics - passed onto offspring 3) All species evolve overtime, species evolves response to environment, passed gen to gen 37 Evidence for Evolution Biological evolution - Genetic change in population of organism over time 5 Main Categories of Evidence for Theory of Evolution: 1) Biogeography 2) Fossil Evidence 3) Anatomy 4) Comparative Embryology 5) Molecular Biology (DNA/proteins) 1) Biogeography a) Geology, study past/present geographical distribution of species, similarity areas 2) Fossil Record a) Chronological, transitional; links between prehistoric, vestigial; once useful 3) Anatomy Homologous Structures a) Similar parts/common ancestor/origin, different functions now 4) Comparative Embryology a) Structures appear during embryonic development; common ancestry 5) Molecular Biology a) Comparing DNA; amino acid sequence depend nitrogen base sequence on DNA 38 Evolutionary Adaptations Adaptation - enhances organism's fitness, increases chance of survival/successful reproduction Animal Struggle: Food, water, protection against weather, predators, disease, accidents Plant Struggle: Water, light, minerals, against weather, disease, eaten Adaptations arise: - Organisms become adapted through natural selection Evolution of Complex Adaptations: - Evolved over time as result of series of small micro-evolutionary adaptive changes - Result of natural selection; chance variations arose particular times in history Three types of adaptations: 1) Structural Adaptations: a) Anatomical i) Changes in shape/arrangement of particular features b) Mimicry i) One species resemble another species c) Cryptic colouration i) Difficult to spot d) Two categories; i) Homologous structures ii) Analogous structures 2) Physiological Adaptations: a) Changes in biochemical functions inside organisms 3) Behavioural Adaptations: a) How organisms respond to environments 39 5 Mechanisms affecting populations; microevolution/changes to allele frequencies in population 1) Mutations 2) Genetic Drift a) Bottleneck Effect b) Founder Effect 3) Gene Flow 4) Non-Random Mating a) In-Breeding b) Assortative mating 5) Natural Selection a) Stabilizing selection b) Directional selection c) Disruptive selection d) Sexual selection 1) Mutations a) Important if mutated DNA in gamete, passed to offspring; may provide advantage 2) Genetic Drift a) Chance changes in allele frequencies → small population size b) Bottleneck Effect i) After disaster c) Founder Effect i) Individuals separate from large to new 3) Gene Flow a) Gain/loss of alleles → movement of individuals/gametes, immigration/emigration 4) Non-random Mating a) Inbreeding - fewer heterozygotes, more homozygotes b) Assortative - similar partner chosen 5) Natural Selection a) Individuals with favourable traits make better suited for environment i) Survive/reproduce 40 Mechanisms of Microevolution - Natural/Sexual Selection Darwin’s 5 points → Natural Selection Conditions 1) Populations have genetic variations 2) Some genetic variations favourable for survival 3) More offspring produced than can survive 4) Offspring that survive have favourable traits for survival 5) Genetic variability of population changes over time 4 Types of Natural Selection 1) Directional Selection a) One extreme phenotype is favoured → shift in phenotype distribution 2) Stabilizing Selection a) Middle phenotype is favoured 3) Disruptive Selection a) Extreme phenotypes favoured 4) Sexual Selection a) Female → Large ovum, stored energy, zygote growth b) Males → Immense numbers of small mobile sperm c) Sexual dimorphism → One sex displays different physical characteristics d) Competition between males e) Mate choice by females 41 Macro-evolution - Speciation Speciation - Reproductive isolating mechanism → Spilling one species into two different species Two main paths by speciation 1) Transformation a) Species A; many small changes → Species B 2) Divergence a) One/more new species arises from parent species; continuing to exist Reproductive isolation - Gene flow stops, genetic divergens occur → genetically different - Lack gene flow → mutations in different populations be independent - Natural selection/genetic drift within two populations will be different - Allele frequencies change differently in separated populations Two mechanisms 1) Pre-zygotic barriers a) prevent sperm from fertilizing egg 2) Post-zygotic barriers a) prevent zygote from developing → fertile offspring Six types of pre-zygotic barriers: 1) Geographical barriers/allopatric speciation 2) Behavioural barriers 3) Habitat barriers 4) Time barriers 5) Mechanical barriers 6) Gamete barriers Two types of post-zygotic barriers: 1) Hybrid sterility a) offspring are infertile 2) Hybrid inviability a) Chromosomal abnormalities/mutations cause embryo to die Two processes which divergent speciation occurs: 1) Allopatric speciation - population split → two geographically isolated groups, gene flow↓ 2) Sympatric speciation - gene flow altered;chromosomal change → non-random/polyploidy Adaptive radiation - change in environment → organisms diversify rapidly 42 Evolution Occurs in Patterns Macroevolution - large scale evolutionary change 4 Major types: 1) Divergent evolution a) Adaptive radiation b) Allopatric speciation c) Sympatric speciation 2) Convergent evolution 3) Coevolution 4) Extinction 1) Divergent Evolution - evolution toward different traits in closely related species a) Adaptive radiation i) Ancestral species undergoes rapid genetic changes → descendent species b) Allopatric speciation i) Starting population geographically divided, evolve → separate species c) Sympatric speciation i) New species forms beside ancestor species 2) Convergent evolution - Similar traits arise in unrelated species → analogous structures 3) Coevolution - One species adaptations cause further adaptation in mutualistically related species 4) Extinction - First examine by Charles Walcott Rate of Evolutionary Change - Darwin/others thought gradualism - 1972; punctuated equilibrium; long periods with little evolutionary change - Shorter time, many changes → adapt to climate, geology, environment 43 Unit 5: Internal Systems: Structure and Function 44 Introduction to Internal Body Systems Organisms - Cells organized into tissues, organs, and organ systems - Multicellular need nutrients, gases, and remove waste - Respond to internal/external stimuli, maintain homeostasis Tissues - Collection of similar cells performing a function - Four types; epithelial, connective, nervous and muscle Organ - Structure composed of different tissues working together → perform complex functions Organ System - One or more organs/structures working together → major body function Anatomy - Study of body structures; through dissection, separation of parts of body structures Physiology - Study of functions/activities or organisms → physical/chemical processes supporting life 45 Human Digestive System 5 Steps in Digestion 1) Ingestion of food 2) Movement of food 3) Mechanical/Chemical digestion 4) Absorption of nutrients 5) Elimination/egestion → unabsorbed food Mechanical digestion - Physical breakdown; chewing, grinding, tearing, mashing, mixing Chemical digestion - Enzymes to break bonds in food molecules, three categories; carbohydrates, proteins, fats - Carbohydrases, proteases, lipases (end in -ase, prob an enzyme) Gastrointestinal tract, alimentary tract, or digestive tract; close with circulatory, carry nutrients Parts of Digestive System 1) Mouth a) Teeth mechanically break down food b) Tongue mix food with saliva; amylase break down starch, sugars c) Epiglottis; flap structure on back of throat over trachea; no food enter 2) Esophagus a) 25cm long, functions; secretes mucus, move food from throat to stomach i) Muscle movement; peristalsis b) Base is cardiac sphincter; closes to prevent reflux of food 3) Stomach a) J-shaped muscular bag, stores/mechanically breaks down food b) Rugae; folds, mucin; protective coating c) Digestive fluids with enzymes break down proteins/lipids, acid kills bacteria d) Chyme; food in stomach, bottom of stomach; pyloric sphincter 4) Small Intestine a) 7m long, lining coated with villi, microvilli increasing surface area for absorption b) 3 parts; Duodenum, jejunum, ileum c) Nutrients from food go into bloodstream through small intestine walls i) 80% of ingested water, electrolytes/salt ions, vitamins, minerals, ii) Secretes enzymes for carbohydrates, proteins, lipids 46 5) Large Intestine a) 2m long, 3 parts; caecum, colon; Ascending, Transverse, Descending, rectum b) Mechanical digestion c) Chemical digestion; Bacterial digestion; Ferment carbohydrates, breakdown protein/amino acids Accessory Organs 1) Liver a) Produce bile; digest fats b) Process nutrients in blood c) Filters out toxins and waste; drugs and alcohol d) Activates vitamin D, K 2) Gallbladder a) Stores bile, releases into duodenum when food enters 3) Pancreas a) Digestive enzymes digest fats and proteins b) Neutralizes acids entering small intestine c) Insulin; regulates blood sugar 47 Mechanical/Chemical Digestion Steps for digestion: 1) Teeth chew food → increases surface area 2) Bolus; chewed ball of food 3) Peristalsis; wave-like contractions of muscles move food forward → circular contractions 4) Rugae; mechanically press and break food 5) Special peristalsis; rhythmic segmentation mix enzymes into chyme Food Polymers - Large molecule made of repeating monomers; smaller molecules - Chemical digestion break down food polymers into monomers for absorption - Major food polymers; carbohydrates, proteins, lipids Enzymes - Help chemical reactions go faster, less energy - Bonds substrate; specific food molecule - Uses water to break down chemical bonds in food polymers → monomers - Lipases → Glycerol + Fatty acids - Proteases → Amino acids - Carbohydrases → Carbohydrates Carbohydrates - Simple sugars bonded together, Amylase; in saliva break down starch - Others produced by pancreas/small intestine; maltase, sucrase, lactase - Most carbohydrate chemical digestion in small intestine Proteins - Polymers; 20 amino acids monomers - Pepsin; starts in stomach, other proteases produced by pancreas/small intestine - Almost all protein chemical digestion in small intestine Lipids - Polymers made of fatty acids/glycerol monomers - Lipases produced by stomach, rest in pancreas - Bile emulsify/separate lipid drops before lipase breaks bond Absorption and Villi - Monomers absorbed at villi, simple sugars/amino acids directly to capillaries - Fatty acids → lacteal vessels, lymph system, then into vena cava 48 Introduction to Respiratory System Purpose - Gas exchange; oxygen brought to cells, carbon dioxide removed Upper Respiratory System Structures 1) Nose/Nasal Cavity a) Hollow, hairs/mucus secreted traps dirt, air is warmed and moistened 2) Pharynx a) Tube connects nasal/oral cavity to trachea/esophagus, carries food/air 3) Oral Cavity a) Allows air into lungs 4) Epiglottis/Glottis a) Cartilage covers glottis; food enters, opening from pharynx to trachea 5) Trachea a) Carries air from nasal to lungs, flexible tube held by rings of cartilage, b) Covered in mucus and moving cilia; remove dirt particles, protect lungs 6) Larynx a) Voice box; makes sound when air passes through Lower Respiratory System Structures - Right lung; 3 lobes, left lung; 2 lobes, space for heart and encased in pleural membrane 1) Bronchi a) Trachea divides to left/right bronchus b) Held open by rings of cartilage 2) Bronchioles a) Branch off bronchi b) NOT held open by rings of cartilage 3) Alveoli a) Tiny damp hollow sacs covered in capillaries b) Gas exchange by diffusion; CO2 exit blood to alveoli, O2 enter blood from alveoli 4) Diaphragm a) Strong muscle separating thoracic from abdominal cavity b) Contracts along with intercostal muscles → breathing movements 5) Intercostal muscles a) Attached to ribs 6) Pleura a) Singular - pleuron; tissue covering lungs 49 Human Respiration Respiration - all processes supplying O2, to cells of body, remove waste CO2 by exhalation Fours main steps 1) Breathing/Ventilation - physical movements of air to/from lungs a) At rest b) Inspiration/inhalation i) Signal from medulla oblongata ii) Nerve signal cause rib muscles/diaphragm to contract iii) Thoracic cavity sizes increases/lung air pressure decreases iv) Air enters lungs c) Expiration/exhalation i) Muscles relax ii) Pressure on lungs increases iii) Air push out of trachea 2) External Respiration - Alveoli a) Diffuse O2 from air in alveoli to blood in capillaries b) Remove CO2 from blood to lungs 3) Internal Respiration - Capillary a) Diffuse O2 from capillaries into cells b) Remove CO2 back to lungs 4) Cellular Respiration - Mitochondria a) Production of ATP energy molecules b) Mitochondria use oxygen, breaks down glucose → water, ATP, energy, CO2 c) Energy from glucose add phosphate to ADP → ATP; power all chemical reactions Molecules diffuse from high to low concentration through cell membranes Diffusion works well with large surface area to cell volume 50 Structures of Mammalian Circulatory System Function - carry nutrients/waste to/from different places in body Three Main Structures 1) Vessels connect all parts 2) Blood carry dissolved nutrients from and wastes 3) Heart pump blood Mammal - Closed circulatory system, blood stay/pumped through series of vessels, 1 direction 3 Major Cycles/Loops 1) Pulmonary Circulation - Heart to lungs 2) Systemic Circulation - Heart to muscles/organs in rest of body 3) Cardiac Circulation - Heart to heart Three Types of Blood Vessels 1) Arteries a) Oxygenated blood away from heart b) Elastic fibres stretch under pressure 2) Veins a) Deoxygenated blood toward heart, valves, veins contract by muscle along vessel 3) Capillaries a) Link veins/arteries, nutrients/wastes exchange between somatic cells/blood b) Nutrients go from blood to cells, wastes go from cells to blood; diffusion c) Capillary beds; collection of capillaries, wall one cell thick increase diffusion Blood - Transport medium for many substances 1) Red Blood Cells a) Biconcave disc shape without nucleus b) Haemoglobin, hold/carry oxygen to all cells 2) White Blood Cells a) Big nucleus/fight infections b) Two main; i) Lymphocytes; fight infections making antibodies, dissolves them ii) Macrophages; eat, digest micro-organisms → phagocytosis 3) Platelets a) Clot blood 4) Plasma a) 55% of blood, straw-coloured; dissolves/carries non-cellular blood components i) Carbon dioxide, glucose, amino acids 51 The Heart - Structure and Function Heart Structure - Two atria and two ventricles - Right atria/ventricle pump deoxygenated blood, separated by atrioventricular (AV) valve - Left atria/ventricle pump oxygenated blood , separated by mitral valve - Septum; Muscle separating two sides - Semi-lunar valve cover arteries leading away from both ventricles - Superior/inferior vena cava bring blood to right atrium - Right/left pulmonary arteries take blood to lungs - 4 Right/left pulmonary veins bring oxygenated blood back to left atrium - Largest artery in aorta; takes oxygenated blood from heart to body Co-ordination of Heartbeat - Heart made of cardiac muscle - Brain electrical impulses cause atria, then ventricles to contract and rest - Soft sounds → atria contracting, louder sounds → ventricles contracting Three Steps to Heartbeat 1) Atrial systole a) When sino-atrial (SA) node → atria contracts 2) Ventricular systole a) When atrio-ventricular (AV) → ventricles contract 3) Diastole a) Chambers are relaxing Blood Pressure - Pressure exerted on walls of the arteries; 2 numbers to measure 1) Systolic pressure; pressure blood exerts on aorta → blood leaves heart during systole 2) Diastolic pressure; pressure blood exerts on aorta → no blood leaves heart during diastole Normal blood pressure - 120/80 mmHg - 120 mmHg - Systolic - 80 mmHg - Diastolic

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