Science Exam Review - Lecture notes 1-13 PDF

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SCIENCE EXAM ONE STUDY GUIDE CHARACTERISTICS OF LIFE 

DOGRACER – what does it take to be alive? o DNA – genetic material o o

Organized – subcellular, cell, tissue, organ, organ system, organism) Growth and Development

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Reproduce – asexual or sexual

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Adapt – population changes lead to evolution Cells – made of cells

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Energy – obtain and use; metabolism-sum of chemical reactions in the body Respond – stimulus may be external/internal; homeostasis-process of maintaining stable internal conditions

SCIENTIFIC METHOD AND REASONING     

Observations are what you notice – these are objective Inferences are interpretations of evidence, reactions, ideas, etc Deductive reasoning starts with a general statement or hypothesis, and examines the possibilities to reach a specific, logical conclusion Inductive reasoning makes broad generalizations from specific observations. Basically, there is data, then conclusions are drawn from the data. The Scientific Method o Purpose – what do I want to learn? o

Research – find out as much about your topic as you can

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Hypothesis – predict what the answer to the problem is Experiment – design a test to confirm or disprove your hypothesis

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Analysis – record what happened during the experiment Conclusion – was my hypothesis correct?

MEASUREMENTS, PRECISION, AND ACCURACY  

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100 is not a measurement, requires a label Fundamental Metric Units o Meter, m (length) o

Kilogram, kg (mass)

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Second, s (time) Ampere, A (electric current)

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Kelvin, K (temperature) Mole, mol (amount of substance)

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Candela, cd (intensity of light)

Important Unit Conversions o 1 cm = 10 mm o 1 inch = 2.54 cm

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1 liter = 1000 ml

o 1 kilogram = 1000 g Precision and Accuracy o Precision expresses how reproducible measurements are:  If I make 5 measurements and each measurement gives nearly the same answer, my measurements are highly reproducible or very precise.  If the same 5 measurements give 5 different answers, then my reproducibility is poor and my measurements are not precise.  Random errors cause poor precision. Random errors are errors that pop up randomly with each separate measurement. o Accuracy is a test of my measured result against an external standard or the true and correct value.  These standards are often accurate, reproducible measurements made by many others.  Measurements must be precise before they can be accurate.  Precision does not guarantee accuracy (you could be getting the wrong answer over and over again).  There can be systematic errors that compromise accuracy.  System errors occur with each experiment  Error in experimental design  Error in calibration of the measuring instrument

BIOMES     

Ecology: the study of interactions of living organisms with one another and their physical environment Community: collection of all organisms living together in an area Habitat: collection of all organisms living together in an area Habitat: the place where an organism lives Ecosystem: a largely self-sustaining collection of organisms and their physical environment

FACTORS THAT AFFECT ORGANISMS 

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Biotic/Living Things o Animals o Plants o

Fungus (kind of in between plants and animals)

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Protists Bacteria

o Archaebacteria Abiotic/Non-living Things o Minerals present o

Wind or absence of wind

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How much sunlight How much water

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 Does it freeze or not? Altitude Climate

THE PATH OF ENERGY IN ECOSYSTEMS 

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Energy flows into the biological world from the sun o Producers/Plants/Autotrophs capture sunlight and transform it into chemical energy by photosynthesis o Consumers/Animals/Heterotrophs obtain their energy from consuming plants and other animals Ocean Ecosystems o Shallow Waters The world’s great commercial fisheries occur on banks in the coastal zones  Intertidal region: areas exposed to air when the tides recede  Estuaries: partly enclosed bodies of water, often forming at river mouths and coastal bays o Intermediate salinity o Very fertile o Fishing industry for oysters, shrimp, crawfish, etc Open-Sea Surface  Upper, better-illuminated waters of the ocean  Rich with phytoplankton and zooplankton  Most occur in the top 100 meters, some are photosynthetic , responsible for about 40% of all photosynthesis on earth  Populations are able to increase rapidly  Nutrient turnover is much more rapid than in other ecosystems Deep-Sea Waters  Little light penetrates beyond the top 300 meters  Few KNOWN organisms  Some fish have bioluminescent body parts  Sea anemones use glass-sponge stalks to catch falling particles  Hydrothermal vent systems support a broad array of living organisms  Autotrophic prokaryotes obtain energy by chemosynthesis (like photosynthesis but with chemicals instead)  Extract energy from hydrogen sulfide to manufacture food  Live symbiotically within the tissues of heterotrophic animals Freshwater Ecosystems  Includes lakes, ponds, rivers, and wetlands  Cover only about 2% of earth’s surface  Strongly connected to land ecosystems  Some organisms can only live in freshwater habitats 

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LAND BIOMES

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o A biome is a terrestrial ecosystem that occurs over a broad area. o It is characterized by a particular climate and a defined group of organisms. o More than 90% of described species occur on land Tropical Rain Forests o Experience more than 250 cm of rain a year (>100 inches) o Richest ecosystem on earth – many different species

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Contains at least half of the earth’s species of terrestrial plants and animals

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15-20 degrees North and South of the equator Unfortunately, they are being destroyed by human activity

Savannas/Dry Tropical Grasslands o Rainfall is seasonal: 75-125 cm annually o Many organisms only active in rainy season o On a global scale, savannas are transitional between tropical rain forest and desert o Contains several endangered species Deserts o Dry places with less than 25 cm of rain a year Vegetation is sparse – plants and animals have various means of water conservation  Camels can drink large quantities of water at one time to survive long dry periods Temperate Grasslands/Prairie o Biome that we live in o Temperate regions found halfway between the equator and the poles o

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-40 deg to 70 deg F 10-30 inches of rain

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Very rich agriculture Often populated by herds of grazing mammals

Deciduous Forests o Mild climate with plentiful rains o o

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o o Taiga o o o o Tundra o o o o o o o

Deciduous trees drop leaves in the winter Four distinct seasons Much forest area lost to farms and towns Average rainfall 30 to 60 inches per year. Extens over vast areas of Asia and North America Conifers are trees with needle-like leaves that are kept all year long The taiga climate has an avg rainfall of 12-33 inches Large mammals such as elk, moose, and bears Found in the far north Winter temps do not reach above 20 F and avg is -20 to 30 F Grasslands that are open, windswept, and boggy Little rain or snow Precipitation totals 6-10 inches of rain a year Permafrost exists with a meter of surface Many large animals  Caribou, reindeer

CLASSIFICATION AND THE VARIETY OF LIFE 

Taxonomy: the description, identification, naming, and classification of organisms o Based on similarities and differences between organisms o Relationships between organisms is shown by a hierarchy of taxonomic levels

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The most accepted basic classification scheme has eight taxonomic levels, including six kingdoms arranged in three domains New classification systems are likely to be developed as DNA analysis reveals evolutionary relationships that were previously unknown.

HIERARCHY OF TAXONOMIC LEVELS          

Domain Eucarya Kingdom Animalia Phylum Chordata Class Mammalia Order Primates Family Hominidae Genus Homo Species Sapiens Mnemonic devices: Dear King Philip Came Over For Green Spaghetti Three Domain Classification – based on cell structure and biochemistry o 1 Domain Archaea o o

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 1 Kingdom Archaea 2 Domain Bacteria  2 Kingdom Bacteria 3 Domain Eukarya

 3 Kingdom Protista  4 Kingdom Fungi  5 Kingdom Plantae  6 Kingdom Animalia 1st Domain Archaea o Kingdom Archaea  Prokaryotic organisms (no nuclear membrane)  Often characterized by living in extreme environments  Some of the oldest species of organisms on Earth 2nd Domain Bacteria o Kingdom Bacteria  Prokaryotic organisms  No nuclear membrane  Contains all known pathogenic organisms rd 3 Domain Eukarya o Kingdom Protista

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 Eukaryotes (have nuclear membrane)  Simple organization  Unicellular or Multicellular without specialized tissues Kingdom Fungi  Eukaryotes  Heterotrophic  Multicellular (except yeast)  Cell walls

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Kingdom Plantae

Eukaryotes Autotropic  Mosses, ferns, gymnosperms, angiosperms o Kingdom Animalia  Eukaryotes  Lack cell walls but have cell membranes  Heterotrophic Scientific Nomenclature o Scientific names are given in Latin, following the format of binomial nomenclature (two name)  Genus species  The first name is always capitalized, the second name is always lowercase.  Always in italics Dichotomous Keys o A dichotomous key is device, based on the physical characteristics of an organism, that can be used to identify an unknown organism  

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FOOD CHAINS AND WEBS  

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A trophic, or feeding, level consists of all organisms feeding at the same energy level Food chain: passage of food through ecosystem trophic levels in a linear path o You can have up to six trophic levels, depending on how many layers of carnivores or omnivores you include Food web: complicated path of energy flow o Animals eat at different trophic levels, most ecosystems have paths of energy that are not linear Energy flows through trophic levels o Primary productivity (Net Check) Total amount of light energy converted to organic compounds in a given area per unit time Net primary productivity (After Taxes)  Primary productivity minus energy expended by the photosynthetic organisms to fuel metabolism Biomass 

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 Total weight of all organisms in an ecosystem About one order or magnitude of available energy is lost from one trophic level to the next. This is the reason why food chains generally consist of only 3 or 4 steps Ecological Pyramids o A plant fixes about one percent of the sun’s energy that falls onto its green parts o Successive members of a food chain incorporate ten percent of energy available in the organisms they consume  Therefore, there are far more individuals at the lower trophic levels  The biomass of the lower trophic levels also tends to be greater The Biogeochemical Cycles o Unlike energy, the physical components of ecosystems are passed around and reused (cycling) o In each cycle the chemical resides for a time in an organism, then returns to the non-living environment

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 Carbon cycle  Nitrogen cycle  Phosphorous cycle Water cycles within ecosystems 

Water cycle = hydrologic cycle

WATER CYCLES 

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Organismic o Surface water does not return directly to atmosphere  It is first taken up by plant roots  It returns to the atmosphere by transpiration from the plant leaves o The cycle is broken when forests are cut down  Moisture is not returned to the atmosphere and could create a semiarid desert Groundwater o Occurs in permeable, saturated, underground layers of rock, sand, and gravel called aquifers o Pesticides, herbicides, and fertilizers are key sources of groundwater pollution

THE CARBON CYCLE 

The carbon cycle is begun by plants who use CO2 to build organic molecules o Carbon atoms are returned to the atmosphere by   

Respiration  Most organisms extract energy from food and release CO2 as a by-product Combustion  Burning of wood or fossil fuels releases trapped carbon in the form of CO2 Erosion  When limestone erodes, CO2 is released

THE NITROGEN CYCLE     

The atmosphere is 78% nitrogen gas However, most organisms are unable to use it how it is Some soil bacteria can break the triple bond and bind its N atoms to hydrogen forming ammonia o This process is termed nitrogen fixation Animals eat plants that have taken up fixed nitrogen Nitrogen reenters the ecosystem through animal excretion and decomposition by detritivores and decomposers

THE PHOSPHOROUS CYCLE     

Phosphorous has no atmospheric form and exists mostly as the mineral calcium phosphate Phosphate ions are absorbed by plant roots and used to build organic molecules like ATP and DNA When animals and plants die and decay, bacteria convert organic phosphorous into ions Low phosphorus levels in freshwater lakes limits the overgrowth of algae An excessive increase in phosphorus, or other nutrients, is called eutrophication

ASEXUAL AND SEXUAL REPRODUCTION

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Why do cells divide? o Growth and development o Repair o Reproduction Mitotic Cell Cycle vs Meiosis Sexual Reproduction o Haploid (half of genetic material) produced by meiosis o Mixing of haploid cells to produce offspring with mingled characteristics o

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Eukaryotes

o Mixing of genetic material Asexual Reproduction o No new genetic material

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 Copies or parents  May have some mixing or crossing May be similar to mitosis or nucleus may stay intact Eukaryotes or prokaryotes Little to no mixing

BACTERIA    

Bacteria are everywhere, most are either harmless or helpful Bacteria are prokaryotic which means there are no packaged DNA in the nucleus, it is scattered around Prokaryotic cells can accomplish all the necessary tasks for life Bacteria shapes o Spherical o o

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Rod-like Spiral

Structure o Cell wall o o

Cell membrane Cytoplasm

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Genetic material Flagella/cilia

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They don’t have a nucleus because they are prokaryotic

Two Kingdoms of Bacteria o Archaebacteria  Ancient bacteria  They exist in extreme environments  They are anaerobic (don’t need oxygen) o Eubacteria  Live everywhere that archaebacteria don’t  Some are autotrophic and some are heterotrophic Bacteria Reproduction o Asexual Reproduction  Binary Fission

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 Bacteria make exact copies of each other  This makes more of the same Sexual Reproduction

 Conjugation  Bacteria combine their genetic material  This creates variety in bacteria – but not more Survival needs o Obtaining food  Autotrophic/photosynthesizing  Heterotrophic o Respiration  Some need O2, some don’t o Endospore Formation  Hard shell that forms for survival in harsh conditions Bacteria and the Living World o Fuel – Methane o

Food – cheese, yogurt, apple cider, olives, sauerkraut, pickles, buttermilk, sour cream

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Natural recycling – bacteria are decomposers. They also convert nitrogen gas in the air into nitrogen that plants need to grow Health and medicine – they can keep you healthy by making insulin, vitamins, and helping with

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digestion Clean up – bacteria are used to clean up oil spills and gas leaks...