Summary

These notes discuss cell biology, covering topics such as the different types of cells, their basic structures, and their functions. The document also explains the differences between prokaryotic and eukaryotic cells.

Full Transcript

Module 1 Kingdoms — plants, fungi, protist and animals Mitosis to divide Cell theory All living things are made of cells Similariti...

Module 1 Kingdoms — plants, fungi, protist and animals Mitosis to divide Cell theory All living things are made of cells Similarities Basic structures and functions on own DNA All cells come from pre-existing cells Cell membrane Ribosomes Prokaryotes Cytoplasm Before nucleus Smaller and simpler than eukaryotic cells No membrane bound organelles Name Function Divided into Archaea and Bacteria Cytoplasm -Liquid background Binary fission to divide -Dissolved chemical substances Four main structures -Holding components of cell - Cell membrane -Protects from damage - Cytoplasm -Stores molecules for cellular - Ribosomes process - DNA in large loop (nucleoid) Gives cell shape - Flagellum and possibly villi Nuclear -Separate chromosomes from Membrane rest of cell -Small holes or pores= passage certain materials -Between cytoplasm and nucleus Nucleus -Transparent and colourless -Stores cells DNA -Responsible for growth and reproduction -Produces ribosomes -Control the developments and functioning of cell Ribosomes -Assist in making proteins -Floating around cytoplasm -Attached to rough ER Chloroplast - ONLY in plant -Photosynthesis occurs here -Inside are little green chlorophylls Golgi Bodies -In most eukaryotic cells -Sorting and processing proteins -Determines which proteins allowed out of cell -Take in ribosomes Lysosomes -Digest and remove waste from cell -Surrounded by layers of lipids acting as membrane Mitocondria -POWERHOUSE -Produces ATP -Responsible for creating 90% of Eukaryotes energy needed More complex -Plants only use at night 10-100 um - 2D images Cytoskeleton -Complex network of interlinking - 1,500,000x mag- resolution 2nm filaments and tubules throughout - Sensitive to vibration and electromagnetic cytoplasm fields -Support shape and help facilitate Scanning electron microscope (SEM) movement - Bombards specimen with beam of Centrioles -Pairs in ANIMAL cells electrons -Formation of spindle for mitosis - Does not pass through specimen - Resolution 10nm Cell wall -Structure, support and protection - 3D images -PLANT -Outside membrane Fluorescent microscopes Sample labeled with fluorescent dye- Cell -Provides protection attached to particular structure membrane -Transport nutrients into cell/ toxic Illuminated with high intensity light out 3D image -Surrounds whole cell -Flexible 1mm= DIVIDE 1000= um( micrometer) -FLUID MOSAIC MODEL 1um= DIVIDE 1000= nm (nanometer) Rough ER ROUGH Symbo Name How many Standard Smooth ER -Millions membrane bound l form ribosomes -Folding, quality and dispatch cm centimetre 100- 1m 1.0 x 10-2 proteins mm millimeter 1000- 1m 1.0 x 10-3 SMOOTH -Associated with lipids um micrometer 1,000,000 1.0 x 10-6 -Manufacture, metabolism, steroid production, hormone nm nanometer 1,000,000,00 1.0 x 10-9 production 0 -Detoxification function Vacuole -PLANT Fluid Mosaic Model - Used as food storage -Cell sap= water + dissolved Cell membrane substances - Two molecules thick -Some occupy 80%-90% of cell - Selectively permeable(only certain in or out) -Animal usually small if there - Permeable to small molecules and lipid- -Help isolate wastes soluble molecules -Maintain water balance - Involved in cell recognition and communication Technology Fluid mosaic model - Hydrophilic- phospholipid head Light microscope - Hydrophobic- fatty acid tails Images up to 1500 x depending on lens ( - Phospholipid tails meet in middle ours is 400 x max) Resolution max 200nm - Carbohydrates and cholesterol scattered Nothing living and non living specimens throughout bilayer Light passes through condenser lens- through specimen- light through convex Proteins lens = Image magnified - Scattered or float throughout bilayer - Many functions Electron microscope 1. Transport Uses electron beam instead of light + 2. Enzymes electromagnets instead of glass 3. Cell surface receptors Greater resolution- shorter wavelength 4. Cell surface identity markers Two types 5. Cell-to-cell adhesion Transmission electron microscope (TEM) 6. Attachment to cytoskeleton - Electrons pass through specimen Factors affecting membrane - Greater difference= faster diffusion - High temp= high rate of diffusion Cholesterol- Gives stability to cell without - Small particle= fast rate of diffusion affecting fluidity Facilitated Diffusion Temperature - Temp increase-fluidity increase= less tight pact - Transport proteins - Temp decrease- fluidity decrease= may - Carrier or channel- specific to one or solidify several solutes - Used by some larger molecules, Proteins- some whole way through electrically charged molecules as simple is - Receptor respond only to signals- to slow for them substances - Carrier- facilitated diffusion or active Osmosis transport, may require energy (Sodium Pass through membrane from less- high potassium pump)- changes shape so molecule can move Isotonic Solution - Channel- spanned membrane, allows - Concentration inside= outside direct passage from one side to the other- - Water molecules move in and out can have open and closed states controlled by ATP Hypotonic Solution - concentration inside > outside Solvent vs Solute - Water molecules move into Solvent= substance able to dissolve other - Swells substances Solute= substance that dissolves in Hypertonic solvent - Concentration inside < outside Dilute solution= only small amount of - Water molecules moves out solute - Shrinks Concentrated= large amount of solute Endocytosis Membrane Permeability Engulfs substances from outside in vesicle Impermeable= none- no pores to bring inside Selectively = some - small pores Portion of membrane folds into itself Permeable= all- large pores Takes in nutrients for cellular growth, function and repair pathogens, disposing What determines movement in membrane of old or damaged molecules Size- small= fast Exocytosis Electrical charge- nature molecules Move inside —> outside Lipid solubility- molecules soluble in lipid Vesicle fuses with plasma membrane to move quickly release continents Removes wastes or toxins, cellular Impermeable communication, cellular membrane Water soluble molecules growth/ repair, cell signaling Ions and polar molecules Surface Area to volume ratio How molecules move across cell membranes Either passive or active SA= outside Passive= no energy V= inside Active= energy/ ATP Needs enough surface area to supply volume requirements and remove wastes Diffusion LARGER= BETTER High- low concentration SA/V Solute and solvent particles free to move No barrier Enzymes Role is to control all chemical processes Simple diffusion Intracellular and extracellular - Moves through semipermeable membrane Organic catalysts without transport proteins Responsible for increasing rate of Required by cells are carbohydrates, lipids, reactions that occur proteins and nucleic acids Can be reused Speeds up or brings about chemical Photosynthesis change Carbon dioxide + water = glucose + oxygen Reactions at lower temps Globular proteins- long chains of amino Chloroplast- light energy converted to glucose. acids- folded into specific shape Specific active site= district chem reaction- Stage 1 called a substrate - chlorophyll captures solar energy to make Substrate specific ATP Compounds/substrates changed into other - Photolysis (water splits in H and 02) compounds (join or separate) Induced fit model Stage 2 - Don’t need light - Combine CO with H - Produces glucose - Takes place in the Stroma Aerobic Respiration - 20 separate reactions each catalyzed by specific enzyme Factors affecting enzymes Temperature sensitive (prefers body Cellular Respiration temperature ) Glucose + oxygen = Carbon dioxide + water Activity level slows till optimum level High/low temps cause denaturing- this is Anaerobic Respiration irreversible- change shape or stops - Environment has no oxygen working - Use molecules other than oxygen pH sensitive - EG) Alcohol fermentation used by yeasts Substrate concentration Inorganic and Organic substances Organic Synthesised by living things and contain Carbon, Hydrogen and oxygen Carbohydrates- can be a source of energy, storage or energy and structural components of a cell Lipids- used for energy storage, parts of membrane and components of hormones Proteins- structural role in cells + tissues Proteins eg enzymes also have functional role DNA- chemical information that controls cell activities RNA- assists in manufacture of proteins Inorganic Part of the non-living world Contain carbon and hydrogen in long chains Water Mineral (sodium, calcium, chlorides) Gasses (carbon dioxide, oxygen) Every cell requires large organic molecules as part of its structure and to maintain biochemical processes Module 2 - Connective tissue- Provides support and ensures different parts of body are bound together Types of cells - Nervous tissue- Communication between all parts- highly specialised to pass Unicellular messages - Either prokaryotic or eukaryotic - Muscle tissue- Skeletal, cardiac and - Bacteria, Alge, Fungi, Yeast smooth - First forms of life - Carriers out all life processes Plant tissues - High SA.V which is more efficient - Meristematic - found in roots and shoots - Moist environment for diffusion and - Dermal tissue- outer layer of stems- osmosis waterproofing, protection and control of gas exchange Colonial - Vascular tissue- Xylem and Phloem- - A group of cells working or organism transport working collectively - Ground- Fills around vascular tissue - May be unicellular or multicellular - Can exist independently- multicellular Autotrophs cannot exist on own - Provide own organic and inorganic Multicellular compounds (water, co2, phosphates) - A community of cells working together to - Photoautotrophs- light energy carry out life processes - Chemoautotrophs- Chemical energy - Different specialised cells - Consists of eukaryotic cells Heterotrophs - Made up of smaller cells (SA:V) - Consuming other organisms - Each cells= different function - Nutrients from living enviroment - Require systems to break down and Stem cells absorb nutrients - found in all multicellular organisms - Can divide Non Vascular plants - Can self renew - Plants without vascular system - Specialised functions for intergal transport Embryonic Stem Cells - Need constant water to live (damp areas) - Pluripotent (Immature= can become many - Nutrients by diffusion and osmosis other cells) - Low numbers in adults Vascular plants Vascular system Adult Stem Cells - Transport and distribution of organic - More specialised than embryonic compounds - Thought to raised in a specific area of - Xylem- water and double nutrients and each tissue minerals from soil- roots - Replenish dying cells and damage tissues - Phloem- Thin walled cells that transport sugars and other products Formation of Specialised Cells They differentiate (PROCESS) when they Root systems specialise(FUNCTION) - Anchor plant Develop structures to carry out function - Large SA Originate from stem cells- ability to divide - EPIDERMAL CELLS-Absorb inorganic Cannot survive independently nutrients from soil - smaller than root hair Communication between cells is vital cells- flatten= increased SA - Animals=bloodstream/ nervous - Water-> root tissues (outer epidermal - Plant= chemical/ physical contact layer) -> Vascular stele -> Xylem tissue - Moves via diffusion/ active transport Tissues - Root cells have, no Chloroplast (no photosynthesis) aerobic respiration Animal tissues - Oxygen diffuses into cells from air in soil - Epithelial tissue- covers body surface Shoot System (STEM) - Structural support - Transport pathway - Above ground - Larynx (voice box)= protecting trachea from food aspiration Shoot system (LEAVES) - Trachea= transports air - Photosynthesis - Bronchi= off trachea, 2 - Transpiration- Release water to cool plant, - Alveoli= capillaries mean co2 and o2 can lift water from roots diffuse - Exchange gas- Release oxygen/ co2 - Oxygen + red blood cell = oxyhemoglobin - Cellular Respiration- Day and Night - Diaphragm- muscle below lungs, contacts - Leaves arranged to maximise sunlight and expands= inhale exhale - Large SA for absorption Fish - More efficient as diffusion is lower in Outermost layer (EPIDERMIS) liquids - Single layer - Gills- protected by an operculum - Transparent sun penetrates under - Constant flow of water across gills - Waterproof to prevent evaporation - Capillaries in opposite direction - Contains guard cells that pair around stoma Insects - Tracheal system Middle Layer (MESOPHYLL) - Spiracles- holes in rows both side of body Palisade - Connected to trachea - One or two rows below upper epidermis - Trachea-> tracheoles-> surface of body - Packed with green chloroplasts Spongy Digestion - Between Palisade and lower epidermis - Fewer chloroplasts Chemical digestion - Irregularly arranged + gaps - Enzymes- break down chemical - Enables gasses and water to move compounds into simpler molecules = between cells and stomata absorbed into blood Physical digestion - Cutting/ mashing food by chewing - Break down into smaller parts= increased SA:V so enzymes can work Digestive System Animal cells= heterophic= obtained food from external environment Breaks down and obtains nutrients Types of digestive enzymes - Amylases= carbohydrates Gas exchange - Proteases- proteins Gas must dissolve in water before - Lipases- lipids diffusing Close contact between gas exchange and Human digestive system blood supply Mammals - Gasses exchanged in lungs Mouth Mechanical digestion - Protected by waterproof covering (skin) Teeth break into smaller pieces - SA increased by bronchioles -> alveoli Increase SA:V - Alveoli= lots of tiny blood vessels- SA! Chem- introduce Amylase MAMMALS Oesophagus Connects mouth and stomach - Nasal cavity -behind nose- warming, Pushes food along moisturising and filtering air (hair and mucus) Stomach Chem- particularly high proteins - Pharynx= passageway from nasal cavity Mech- churning food to esophagus and larynx Length of time = diet - Epiglottis= flap above trachea prevents food in windpipe Small Intestine Made of duodenum, jejunum and ileum SIEVE TUBES Absorbs nutrients from food - Long thin cells with pores and perforated Folds called villi- finger like cell walls micovilli - Contain mitochondria and ER Large SA= absorbed quickly - End to end- form channel Transport into capillary or lymph - Share cytoplasm vessels to distribute through body COMPANION CELLS Liver Absored food travels to liver - Alongside sieve Detoxifies blood - Contain nucleus and organelles sieve lack Balances protein, glycogen and - Provide ATP and nutrients that assit in sugar in body loading and unloading of sugars Large Intestine Water and salts absorbed Stomates Undigested materials, bacteria, - Enable gaseous exchange cellular material, some water - Found in plant leaves + some stems and salts exit the system as - Regulate gas exchange faeces - Control water loss by changing size of pore Caecum Lenticels - Main function to absor fluid and salts after - Porous tissue with large intracellular completion of intestinal digestion spaces - Walls are lined with thick mucous - Found in bark of woody stems + roots of dicotyledons flowers Guts - Pathway for direct gas exchange between - Plant cells have toug cellulose cell walls internal tissue and atmosphere - Must be broken down before contents can be released Cuticles - Herbivores use microorganisms that live in - Outermost layer of leaves, fruits, flowers digestive system to read down cellluose in and non woody stems fermentation process - Protects plants against drought, extreme temps, UV, chemical attacks, mechanical Transport system injuries and pest/pathogen infections A system of vessels+ transport medium+ driving mechanism Open and Closed System Open Simple plants (algae) rely on diffusion and active - Blood rather than being sealed, might be transport openly exposed to environment (e.g Advanced plants (Ferns) Vascular tissues digestive tract) - Use Hemolymph (lymph+ blood+ intestinal Distribution of vascular tissues fluid) rather than blood - Found in bundles - Hemocoel- open body cavity- both - Xylem= star/cross with phloem in between digestive and circulatory functions arms - May have arteries to transport blood to - Centre of roots- stem- leave stalk- veins in tissues but do not circulate leaves Xylem - Xylem= xylem tracheids+ xylem vessels+ parenchyma+ fibres - Lignin thickenings laid in rings/ spirals/ other pattens - Prevent walls from collapsing+ osmosis - Fibres support xylem tissue and parenchyma/ storage - Xylem supports reproductive function Phloem Closed - 2 types - Blood contained in vessels at all time- never leave - Heart can be 2,3 or 4 chambered Plasma - Heart pumps under high pressure 90% water 10% proteins - 4 chambered most effective - Arrives substances dissolved or suspended Blood vessels - Carries Arteries Blood cells - Carry oxygenated blood away from heart Plasma proteins- immunoglobulin etc to other organs Nutrients- Amino acids, glucose etc - Thicker walls to withstand pressure Gasses- oxygen, carbon dioxide - Elastic to be able to expand with pulse Waste products- uric acid, area etc - Branch into smaller arterioles Ions- sodium, chloride, calcium etc Veins Hormones - Carry deoxygenated blood to heart Vitamins - Low pressure - Walls thinner, not elastic and lumen wiser Heart - Muscles in tissues contract- propel blood - Pumps blood around body - Valves- prevent blood going backwards - Humans have 4 chambered heart Capillaries - Deoxygenated returns right atrium via - vessels- bring blood close to tissue Superior Vena Cava + inferior vena - Only one layer for diffusion cava—> Right ventricle—> Pulmonary - Structure suited for slowing down flow of artery to lungs blood - Oxygenated returns to left atrium via - Blood remains but any chemical pulmonary vein —> left ventricle —> substance leaves pumped via aorta to all areas of body - Left ventricle = thickest wall since pump Lymphatic system blood to rest of body Network of tissues and organs that rids the body - Blood + body= systemic circulation of toxins, wastes and other unwanted materials. - Blood, heart, lungs=pulmonary circulation Function to transport lymph (fluid containing white-blood cells) throughout the body. Composition of blood - Changes as it moves around body Blood depends on organ it moves through Red Blood Cells (Erythrocytes) - Transport oxygen (Haemoglobin) - Form bone marrow from adult stem cells - As cell matures nucleus go so more hemoglobin can fit (red pigment) - Biconcave and flat at center= more pliable do fit through capillaries - 7 micrometers— lasts 4 months - 46 million per mL of blood White Blood Cells (leukocytes) - Defense of the body - Produced in bone marrow - - Found in tissue- can go through capillaries - 50% bigger than erythrocytes - Have nucleus - 400,011,000 per mL of blood Platelets (thrombocytes) - Clotting blood - Crescent shaped - Half size of erythrocytes - 400000 per mL - Platelets stick to each other and fibres - Platelets break open releasing enzyme thromboplastin- clotting blood - Platelets clump to stop bleeding Module 3 - A frame dropped onto ground at random points in the study area - The more ‘drops’ the better Ecosystems - Average number of organisms per - Combination of all the organisms- living quadrant is calculated non living Abiotic and biotic factors/ parts - Equation is to be used - Act on characteristic of an organism and effect ability of organism to survive and reproduce - As ecosystem changes animals might not An abundance in animals be able to survive and adapt Technique based on a number of assumptions - 2 types of ecosystems - No population change through migration, Aquatic birth or death between sampling periods Terrestrial - All animals are equally able to be caught - Aquatic abiotic= water flow, salinity, temp+ (trap happy/shy) - Terrestrial abiotic= Wind, soil,temp,water + - Marked animals are not prohibited in their ability to move and reproduce/ mix freely Selection pressures - Factors that influence change in survival Changes in population over time - Drives natural selection Cane toads - Random variations make them better - Introduced to Australia 1935 to control the suited to changing environment cane beetle - Biodiversity essential for survival - Produced at rapid rate - Adapted to suit Australia (No predators, Australia feed at night, absorb water through skin) Abiotic- rainfall, temp, landform patterns, - Adapted to move faster- prone to arthritis vegetation - Predators have increased resistance Biotic- distribution/ abundance of organism towards the toxin and reluctance to eat cane toads Abundance and distribution - Red Belly Blacks have gotten smaller to Abundance- how many species in ecosystem reduce ability to swallow frogs Distribution- where it is found Prickly pear Ecology - Introduced to Australia start cochineal dye - Study of living things and their industry environment - Lack of Environmental pressures= spread - Inter-relationships between life forms and rapidly factors - Use different sampling techniques Adaptations - Organisms are adapted to suit their Population trends environment as a result of evolutionary - What abiotic and biotic characteristics change species most suited to - Adaptation is a characteristic that makes an organism suited for its environment Transects - Results as a change via mutation, when - Narrow strip crosses entire area being cells divide studied from one side to other - Accurate easy method Structural adaptations - Plan sketch or profile sketch - How an organism is built - PLAN- Ariel or surface view, scale PLANTS distribution of organisms - Eucalyptus- waxy leaves to minimise - PROFILE- side on view of an area show transpiration of water and exposure to distribution along line sunlight - Useful to deter main changes in ANIMALS vegetation with altitude or aspect - Wombat- muscular shoulders and large claws for digging Measuring abundance of a species Physiological adaptations Quadrant Method - How an organism functions - Used for slow or non moving organisms PLANTS - Salt tolerant plants minimise salt to its by - Reptiles—> mammals increasing water content in the vacuole - Some became extinct other thrived ANIMALS - Penguins convert their diet to a fat layer to Microevolution vs Macroevolution keep them warm - Macroevolution—> millions of years- results in new species Behavioral - Microevolution —> shorter periods - no - How an organism acts and behaves new species but change in past ones- can PLANTS lead to difference in races/ varieties - Venus fly trap gains nutrients via insects ANIMALS Convergent vs Divergent evolution - Pufferfish pumps air into stomach to Convergent frighten predators - Distantly related species that moved to similar environments and similar selection Darwin Finches pressures - Had different beak sizes, colours and leg - Evolve similarly length Divergent - Depended on which island they were on - Ancestral species radiates into number of and the conditions descendent species - Influenced by various selection pressures Charles noted - Variations in populations = heritable Gradual Natural selection vs Punctuated - More organisms born than the Equilibrium environment can sustain Gradualism - Survivors pass of the traits - Population slowly diverge by accumulating changes in characteristics due to Theory of evolution by natural selection pressures Diversity allows adaptations to change in an - Common ancestor environment - Small variations - Living organisms arose from common Punctuated equilibrium ancestor or life form - Occurs in short bursts of rapid change - Differences apply living things change - Then long periods of stability over time Evolution of the Platypus Biological Diversity - Similar features to birds, reptiles and Diversity allows for adaptations mammals - Genetic = Genetic makeup in a species - Genetic evidence monotremes split off - Species = Diversity of species marsupials and mammals - Ecosystem= Variations of ecosystems - Platypus + echidna= common ancestor - Uses electric pulses to sense prey Genetic Diversity - MACROEVOLUTION - Important for population to adapt - No variation is detrimental Evolution - More genetic diversity= chance of survival - Dramatic time scale - Depends on length of generations and Natural selection change in Environmental factors Organisms must possess traits that favor their - Similarities between extinct and modern survival in that environment species - Variability= All populations have random - Supported by genetics, biology and differences paleontology - Heritability= Variation must be inherited - Similarities can be in body parts, cell - Over reproduction= produce more structure, biochemistry, embryo offspring than the ecosystem can sustain development and vestigial structures - Competition= best suited traits thrive nad - Greater similarities = closely related reproduce Biochemical evidence Diversification of life -All living things share same macromolecules - Unicellular —> multicellular (proteins, dna and biochemical processes) - Multicellular —> fish/ amphibians - Biochemistry study of chemicals found in body - Amphibians —> reptiles - Evidence based on fact certain enzymes and - Fauna in Asia and Australia striking chemical processes are found in cells different divide along a line through Balia and Borneo Amino acid sequencing Evidence - Proteins= component of all living things - Distribution of flightless birds suggest - Made up of amino acids common ancestor (Emus, Ostriches) - Sequences are analysed and similarities and differences are identified Fossil evidence - Differences imply evolution - Provide direct evidence - More differences= longer time - Sequence which fossils laid down= order DNA Hybridisation they were formed - Samples are removed - LAW OF SUPERPOSITION - Compared then mixed - Two stands combine= hybrid DNA Microevolution - Tighter the binding= closer matched - The influence of physical and chemical - Heat applied to determine how tight change in the environment in DNA sequencing micro-evolution - Exact order of bases compared with similar fragment Modern day evolution - Piece of DNA then isolated Cane toads - Multiple copies made with dye - Faster cane toads reproduce more- slowly - DNA sequencer graph then print out getting faster sequencing Antibiotic Resistant Bacteria - Share common ancestor= fewer - Antibiotics= chemical differences - Strains of Bacteria developing are nor affected by antibiotics Limitations of biochemical evidence - Changes that occurred in past but reverted might not be identified - Complex, expensive and require specific equipment Comparative anatomy - Similarities and differences in structure of living things Homologous structures (Divergent) - Same basic plan but modifications - Have same origins Analogous structures (Convergent) - Look similar but different - Started off differently but evolve to look similar Vestigial Structures - Parts that no longer serve a function Comparative Embryology - Related species show similarities in development Biogeography - Study distribution of organisms - New species arise when genetically isolated or geographically isolated - Some continents share similar organism though separated by large oceans - Should resemble species they share a habitat with Wallace’s line Module 4 Realized Niche - All aspects including interactions are restricted by other organism Biosphere: Part of earth that contains life Predicting consequences for population in Biotic Impact factors Ecosystems - Organism abundance affect other Predation abundances - Affect distribution and abundance of prey - Interactions might be pos, neg or neutral - Effects- size of ecosystem, number of - Food chain determines neg or pos effect shelters, birth/ death rate, food avavlibilty of the abiotic and biotic system for prey - Effects; food resources, mates, light, Competition nutrients, water - Short term= decrease in population in one or both species Predator/ prey - Long term= degradation of environments, - Feeding relationship decline in diversity or extinction/evolution - Predator obtains food by killing prey Symbiosis - Abundance of predator and prey fluctuate - Increased evolutionary diversity Competition - New species - Usually for resources in environment that - More resilient ecosystems is of limited supply Disease - Competition involves risk to competitors - Any process that adversely affects the but rearwards outweigh risk normal functioning of tissue in organism Animal species - Alter food webs= affected species decline - Competitions may be for mates, food, shelter or hiding places Recent extinctions - Various defense mechanisms Climate change Plant species - Earth dries out after ice age Allelopathy - Rainforests now filed with Eucalypts - Phenomenon where an organism - Hotter= fires and droughts produces one or more bio chemicals that - Animals and plants that survived changed influence germination, growth, survival flora and fauna and reproduction Indigenous people Symbiosis - Used fire to back burn and regenerate - Interaction where two organisms live grasses to attract more animals together and is beneficial to at least one of - More animals for hunting them - Dingos reduced diversity of carnivores OBLIGATE RELATIONSHIP Nutrients - Species depend on each other to live - Low level of nutrients= dry soil MUTUALISM - Smaller animals= sustained on less - Both organisms benefit COMMENSALISM Superposition - One species in benefited, other not - Layers of silt or mud on top of each other harmed nor helped form sedimentary rock Parasitism - Horizontal layers (STRATA) Porosity - Rock layers with same fossil= same time - Host organism feeds on another without killing or harming it Aboriginal history More serious (bacteria) invade hosts body - Rock paintings feeding so it becomes sick and may die - Types and number of animals changed over time Niche - Indicators of climate change Niche is part of the ecosystem where no two species can occupy the same niche. Geological Evidence - Allows reconstruction of timeline of events Two species can occupy the same ecosystem but - Atmosphere changes from anaerobic to different niches. aerobic Fundamental Niche - Prokaryotes increase oxygen - Perfect conditions for organism to live and concentration in ocean reproduce, no competitors, predators or parasites - Precipitate accumulated at bottom forming - Most historic extinctions are on islands, iron rich layer because small habitat loss is devastating - Oxygenation event changed Earth's - Mass extinction= entire families and atmosphere orders are wiped out at same time across the world Paleontological Evidence - Study of fossils Past to inform the future - Fossils are preserved remains, - BIologists estimate rates of extension by impressions or traces any listing habitat loss and disruptions - MICROFOSSILS are tiny remains e.g - Over explorations of resources bacteria or invertebrate shells - Introduced species - Created due to alternating layers of - Disruption of ecological relationships carbonate or silicate sediment, produced - Sclerophyll= ve gittai on with leaves that by the trapping, binding or precipitating of are tough, thick and waxy cuticles minerals - Fossilised soils contain large Biodiversity and the Australian Government concentrations of carbon Important to maintain biodiversity as - CHEMOSYNTHESIS- organisms use Direct economic value (Plant meds) inorganic compounds available from their Indirect economic benefit (honey) environment Ethical right to exist Aesthetic value Ice Core Drilling - Environment Protection And Biodiversity - Annual record of gas and dust in Conservation Act (1999) atmosphere is left in ice - Monitoring threatened species or - Scientists drill into ice- extract gasses ecosystems that provide economic value - Build climate record Greenhouse Effect Arctic snow - Where the sun delivers large amount of - Forms as layers energy to the earth that is absorbed by the - Deeper lays repress ancient events environment both natural and manmade - As snow falls gasses and particles from - They release it back into the atmosphere atmosphere are trapped - Gasses in the atmosphere will reflect the - (Pollen, dust, volcanic ash, radioactive heat back to the surface thus trapping the particles, bubbles ) heat - Best places where temp not rise above 0 - This helps keep earth warm enough to celsius (Greenland, Antarctica) sustain life Dating fossils Enhanced greenhouse effect Relative dating Imbalance from carbon dioxide and oxygen has - Determine if on rock or geological event i occurred- the two combine and causes increased older or younger without knowing its concentration of greenhouse gas specific age Impacts Radiometric Dating - Blocking of infrared light from the ground - Based off content of radioactive isotopes escaping to space - Potassium, Carbon - Disrupted the equilibrium- energy - Unstable isotopes undergo radioactive absorbed not emmited decay - Resulted in global warming - More half live= older Carbon Dating Climate change - All living things absorb carbon from - Long term alteration of temperate and atmosphere, food and natural radiation typical weather patterns - When they die they stop absorbing - Particular location or planet as a whole Carbon-14 and it begins to decay - Primary cause= burning of fossil fuels Gas analysis which emits gas and adds heat - Isotopes of oxygen can be used to give us - Humans are responsible for global a record of ancient water temperatures by warming analisi of ice cores Influences - Solar energy output from sun Extinction - Variations in earth orbit around the sun - Leading cause is habitat loss - Volcanoes realise carbon dioxide - Temp of oceans - Amount of ice cover on continents Human factors - Burning of fossil fuels - Modern agricultural practices - Land clearing Thomas Malthus His theory is that food production will not be able to keep up with the growth in human population, resulting in disease, famine, war and calamity Therefore bringing degraded ecosystems back to life, increases their benefits to society and biodiversity. Typically these ecosystems are missing many species that keeps the ecosystem in balance.

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