Environmental Biology BIOL 107
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Chapter2 FRAMEWORKS FOR UNDERSTANDING SCIENCE SYSTEMS AND ETHICS WHAT IS SCIENCE The systematic precise objective way to study the natural world Science assumes that studying the world in a systematic way we can obtain valuable insights about our environment Methodically and logically Science demands evidence and tries to eliminate bias See Table 21 on page 36 to learn some Basic Principles of Science Parsimony also known as Ockham s razor is an important principle used in science 0 The explanation of unknown phenomenon should be attempted in terms of what is already known about the phenomenon o lfthere are several plausible explanations the simplest one should be accepted don39t make things more complex than they ought to be Science use models or paradigms that provide a framework of interpreting results and developing theories The accumulation of evidence can cause paradigms to be discarded and new ones created Reproducibility science is a process that includes repeatable observations and testable hypotheses Discovery or descriptive science describes natural structures and processes as accurately as possible through careful observation and analysis of data Data can be quantitative and qualitative In a controlled experiment 0 The control group is the one in which all variables are held constant 0 The experimental group is the one in which one factor or treatment is varied o The variable is the condition of an experiment that is subject to change and that may influence the outcome of the experiment In blind experiments those carrying out the experiment don t know until after data have been gathered and analyzed in order to avoid treating the experimental and control groups differently ln doubleblind experiments neither the subject nor the experimenters know who is receiving the experimental or the control treatment Deductive and inductive reasoning Inductive reasoning begins with observations and draws conclusions general principle o What do all these facts have in common 0 From many examples to all possible examples inductive leap Verifiable observations and measurements are the data singular datum of discovery science This dependence on observations demystifies natural phenomena and distinguishes science from supernatural explanations Inductive conclusions are generalizations that summarize many concurrent observations Deductive reasoning begins with supplied information called premises and draws conclusions on the basis of that information o It discovers relationships between facts 0 lfthen quotIf all organisms are made of cells and humans are organisms then humans are made of cellsquot Deductive process flows from general observations to a specific conclusion A good explanation of inductive and deductive reasoning httn39lskenrlir 39 quot quot 1htm Hypotheses and Theories A hypothesis is a tentative answer to some question It is an educated guess A theory in science is a comprehensive explanation supported by abundant evidence which is widely accepted by the scientific community A theory is validated by a continuum of observations and experiments The common use of the word theory is more applicable to a hypothesis in science and not to a scientific theory For many people a theory is speculative and not supported by facts A scientific theory produces many hypotheses that can be tested Probability is the measure of how likely something is to occur 0 Probability is based on a set of previous observations or on standard statistical methods 0 Scientists often increase their confidence in a study by comparing results to a random sample or a larger group Many statistical tests focus on calculating the probability that observed results could have occurred by chance Ecological tests are often considered significant if there is less than 5 probability that the results were achieved by random chance ln manipulative experiments the scientist alters one of the conditions while the other variables are held constant in order to observe what happens Natural experiments involve observation of events that have already happened In blind experiments the researcher doesn t know which group is treated until after the data have been analyzed In doubleblind experiments used to tests drugs neither the subject nor the researcher know who is in the treatment group and who is in the control group In a controlled experiment the groups in which all variables are held constant THE SCIENTIFIC METHOD It is not a rigid procedure Requires evidence to IogicaIIy solve problems 1 Make observations CurIOSIty 2 Ask critical questions 3 Formulate hypothesis A hypothesis is an educated guess proposed as a tentative answer to a specific question or problem 4 Predictions are IogicaI consequences of the hypothesis Make a prediction that can be tested 5 Test the prediction controlled experimentation Control group in a controlled experiment the groups in which all variables are held constant The experimental group differs from the control group in only one variable Both groups are then compared 9 Collect data Interpret data 8 Draw conclusions Hypothesis supported or not Process which outlines a series of steps used to answer questions A paradigm is a model that explains how the world works 0 It determines how we think about a phenomenon Scientific credibility depends on the repeatability of observations and experiments Science is a social process Most scientists work in teams and research groups include both graduate and undergraduate students Scientists subject one another to careful scrutiny and check on each other39s claims by repeating the experiments Paradigm shift occurs when the majority of the scientists admit that the old explanations are inadequate and do not explain new observations Science and technology are associated In many instances technology results from scientific discoveries applied to the development of goods and services Many technologies are goaloriented applications of science Not all technologies are applied science Technology in general predates science Scientists have the responsibility to educate politicians bureaucrats corporate leaders and voters about how science works and about the potential benefits and hazards of specific technologies There is an important and crucial relationship between science technology and society SYSTEMS 1 Environmental science is a science it uses the scientific method See Ch 1definition 2 Environmental studies are multidisciplinary including sociology economics and other nonscience topics See Ch 1definition 3 Environmentalism is mission oriented it attempts to influence attitudes and policies that affect our environment Systems consist of many interrelated components feedbacks and flows Positive and negative feedback mechanisms keep the system in equilibrium functioning in a controlled fashion within certain parameters Systems are resilient They recover after disturbances and destructive events Open systems receive input eg energy from outside the system Emergent properties are characteristics of the whole functioning system that are quantitatively or qualitatively greater than the sum of all of its parts CRITICAL THINKING Critical thinking means correct thinking in the pursuit of relevant and reliable knowledge about the world Another way to describe it is reasonable reflective responsible and skillful thinking that is focused on deciding what to believe or do Steven D Schafersman I httpwww freeinnuirv 39 H39Iil linn hfm A set of skills that help us evaluate information and options in a systematic purposeful efficient manner T HELPS US IN Discovering hidden ideas and meanings Developing strategies for evaluating reasons Evaluating conclusions Recognizing the difference between facts and values Avoiding jumping to conclusions STEPS 1 Identify and evaluate premises and conclusions in an argument N Acknowledge and clarify uncertainties vagueness equivocations and contradictions 9 Distinguish between facts and values 4 Recognize and interpret assumptions 01 Distinguish the reliability or unreliability of a source 6 Recognize and understand conceptual framework WHAT DO NEED TO THINK CRITICALLY Skepticism and independence don39t believe everything you hear or read Openmindedness and flexibility be willing to consider different points of view Accuracy and orderliness deal systematically with parts of a complex whole Persistence and relevance stick to the main point don39t allow diversions or personal biases lead you astray Contextual sensitivity and empathy imagine being in someone else39s place Decisiveness and courage draw conclusions and take stand when the evidence warrants doing so Humility realize that you may be wrong and that reconsideration may be called for in the future Other resources htt wwwausthinkor critica httpwww freeinnuirv quot39 39H39Iil llinn hfm ETHICS A branch of philosophy concerned with morals and values Morals distinction between right and wrong Values ultimate worth of actions or things Ethics evaluate the relationships rules principles or codes that require or forbid certain conduct Some consider ethics and morals as the same concept and do not distinguish between them ENVIRONMENTAL ETHICS is concerned with the moral relationship between humans and the world around us Some ethical questions Do we have special duties obligations or responsibilities to other species or to nature in general Are there ethical principles that constrain how we use resources or modify our environment If so what are the foundations of those constraints and how do they differ from principle governing our relations to other humans How are our obligations and responsibilities to nature weighed against human values and interests Do some interests or values supersede others ARE THERE UNIVERSAL ETERNALLY VALID ETHICAL PRINCIPLES OR MORAL LAWS o Universalists think there are universal ethical principles either revealed by God or discovered through reason and knowledge 0 Relativists think everything depends on the person society or situation there is right and wrong but no transcendent principle that dictates whether a fact is right or wrong Everything depends on the interpretation of facts ethical values are contextual o Nihilists claim the world makes no sense and there is no reason to behave morally Everything is arbitrary and there is no meaning or purpose in life except struggle for existence power and strength 0 Utilitarians hold that right actions bring good to the greatest number of people Hedonists fall under this category pleasure and happiness are the sole good in life 0 Postmodernists believe that nature is whatever we believe it to be It is arbitrary ever changing socially constructed One point of view is not betterthan other VALUES RIGHTS AND OBLIGATIONS o Moral agents are capable of acting morally or not and should accept responsibility for their actions eg most adult humans 0 Moral sub39ects cannot act morally but have moral interest of their own and can be treated rightly or wrongly by others eg children 0 Moral extensionism widening perspective that ALL humans have inalienable rights 0 lnalienable rights of all humans e g life liberty and the pursuit of happiness 39 39 html httpwww un nrnOve 39 o Moral extensionism the widening perspective of whom we consider ethically significant 0 lnherent values intrinsic or innate worth 0 Instrumental values conferred or given valued for its use only Should moral extensionism include nonhumans Do animals have rights Should we extend this to lower forms of life like bugs fish fungi etc And to nonliving things like rivers mountains lakes the oceans rocks and soil Many philosophers think that reason and consciousness are essential for moral consideration Others considers than sentient feeling perceptive beings deserve to be considered moral subjects What do we do with nonsentient beings like rivers and rocks We give legal standing to corporations although they are creations of the imagination Should ecosystems forests etc also have legal standing RELIGIOUS AND ETHICAL PERSPECTIVES BIOCENTRIC all living things have an inherent value not only humans Humans are only one of many species Living organisms have an intrinsic value whether they useful to us or not All living things are worthy of respect Animal rights advocates emphasize one or few species Emphasis on the individual organism ratherthan the population of organisms Shamanism Buddhism Shintoism Taoism and Native American Religions share this reverence for nature Various branches of Christianity Judaism and Islam share many beliefs about nature and our role in it ANTHROPOCENTRIC the world has been made for our domination and only humans have inherent rights and values 0 Humans are masters of the world with a unique set of rights and values 0 Because of our intelligence and creativity or because our unique place in God39s plan humans have a justification to dominate nature humanism 0 Nature is only a source of materials for humans STEWARDSHIP humans have a responsibility to care for nature creation 0 Caretakers of and partners in nature rather than dominators of nature 0 Humans are part of nature not outside nature 0 A number of Christian Jewish and Islamic groups have played important roles in nature protection ECOCENTRIC processes like evolution adaptation biogeochemical cycles and other ecological processes are the most important parts of nature 0 Individuals do not count for much humans are mostly a negative influence ECOFEMINISM a nonhierarchical pluralistic relationship oriented philosophy 0 Many feminists believe that neither Eastern nor Western religions are sufficient to solve environmental problems The problem comes from the patriarchal system Oppression of women and nature are related and stem from the malepatriarchal system People see themselves as related to each other and to nature Not male dominated patriarchal Cooperation ratherthan competition a network of personal relationships Some ecofeminists have extended the movement to include racism and social inequalities Ecofeminists contend that patriarchal systems of domination and duality cause both environmental degradation and social dysfunction They call for a more pluralistic nonhierarchical caring treatment of both nature and other people Ecoterrorism involves extremist views on environmental issues and animal rights and is a fringeissue form of terrorism aimed primarily at inflicting economic damage on those seen as profiting from the destruction and exploitation of the environment Adherents go way beyond mainstream environmentalists and animal activists to acts of violence justi ed on grounds that mainstream efforts aren39t enough and they often compare themselves to antislavery abolitionists or opponents of Nazi death camps httpfacultyncwceduTOConnor429429lect16htm Other sites on ecoterrorism httpwww 39 nrnindex nhntitleEcoterrorism httpwww answers topi 39 ENVIRONMENTAL JUSTICE Minorities are usually exposed to greater pollution and environmental hazard by living in places where wastes are dumped industrial facilities are built etc LULU locally unwanted land use Environmental Justice combines civil rights with environmental protection to demand a safe healthy lifegiving environment for everyone Uneducated and powerless people can often be tricked or intimidated into signing socially and environmentally disastrous contracts Poor minority communities at home and abroad are being increasingly targeted as places to dump unwanted wastes There is Environmental racism inequitable distribution of hazards based on race quotLULU locally unwanted land usequot and quotNIMBY not in my backyardquot Toxic colonialism targets poor communities in Third or Fourth World countries for waste disposal flight of polluting companies across the border lntergenerational justice should we care about next generations Chapter 16 AIR POLLUTION Pollution means foul or unclean Chemical and physical changes brought about by either natural processes or human activities resulting in air quality degradation are called air pollution Air pollution is generally the most widespread and obvious kind of environmental damage NATURAL CAUSES Natural causes of pollutants are volcanoes bacterial metabolism in decaying organic matter in swamps intestine of ruminants and termites pollen spores viruses dust etc In many cases the chemical composition of natural and human pollutants are the identical and their effects are inseparable e g C02 hydrogen sulfide H28 Many natural pollutants are harmless at natural occurring levels but when humans add to these natural levels disruption of natural cycles may occur ANTHROPOGENIC CAUSES Primary pollutants are released directly from the source into the air in a harmful form Secondary pollution occurs when chemicals are modified into a harmful form once they are in the atmosphere or are produced by a chemical reaction in the air Fugitive emissions are those that do not go through a smokestack e g dust burning of fossil leaks CONVENTIONAL POLLUTANTS US Clean Air Act of 1970 designated seven major pollutants sulfur dioxide carbon monoxide particulates hydrocarbons nitrogen oxides photochemical oxidants and lead They are the major contributors to ambient air degradation These pollutants are also called criteria pollutants There are natural sources for some of these pollutants Sulfur dioxide and other sulfur compounds 0 Are produced by erosion of sulfatecontaining soil burning fuel burning biomass volcanoes and oceans o In urban areas anthropogenic sources make 90 of the sulfur in the air 0 Cause acid rain when dissolves and reacts with water 0 US and China are major produces of sulfur in the air mostly through the burning of coal 0 Sulfur dioxide reacts with water in the air and makes sulfuric acid which is a major component of acid rain Nitrogen oxides o Are produced when nitrogen in fuel or air is heated to temperatures above 650 C 1200 F in the presence of oxygen or when soil bacteria oxidize nitrogen containing compounds 0 Nitrogen monoxide reacts in the atmosphere to produce nitrogen dioxide which in turn reacts with water to produce nitric acid 0 Nitric acid causes acid rain and health hazards Carbon oxides C02 0 Carbon dioxide is the most common form of carbon in the air 0 90 of the C02 produced each year is from respiration 0 Some of the C02 is reabsorbed by photosynthesis and the rest accumulates in the atmosphere 0 Carbon dioxide is a greenhouse gas CO o Is produced by the incomplete combustion of fossil fuels and anaerobic decomposition of organic material lnhibits cellular respiration by combining with hemoglobin About 90 of the CO in the air is 39 in 39 39 39 39 quot that produce ozone Particulate matter 0 An aerosol is any solid particles or liquid droplets suspended in a gaseous medium eg air 0 Atmospheric aerosols include dust ash soot lint smoke pollen spores algal and fungi cells and many other materials 0 Many of these aerosols reduce visibility and leave deposits on windows and other surfaces 0 Particles smaller than 25 micrometers can be drawn into the lungs during breathing and cause asthma and the destruction of respiratory tissues Metals and halogens Many metals are released in the atmosphere in the form of metal fumes or suspended particulates by fuel combustion ore smelting and disposal of wastes Lead is a metabolic poison and a neurotoxin that binds to enzymes and inactivates them 0 Gasoline and ore smelting are major sources of lead in the ambient air Mercury is a neurotoxin that accumulates in biological systems 0 Major source of mercury in the air are coalburning power plants and waste incinerators Other toxic metals are beryllium cadmium thallium uranium cesium and plutonium Halogens chlorine fluorine bromine iodine are highly reactive and destroy animal and plant tissues 0 Chlorofluorocarbons CFC destroy the ozone layer by releasing fluorine and chlorine o The ozone layer protects the earth from ultraviolet radiation 0 Sources are spray propellants refrigeration compressors and foam blowing Volatile organic compounds VOCs o VOCs are organic chemicals that exist as gases in the air 0 Are released into the atmosphere by plants and animals and by human activities burning fuel industry chemical plants and refineries Plants release isoprenes and terpenes Wetlands rice paddies bacteria and animals release large amounts of methane lndustry releases benzene chloroform formaldehyde phenols etc 0 O O 0 They are converted to CO C02 and photochemical oxidants Photochemical oxidants o Are secondary pollutants produced by atmospheric gases when they react in sunlight 0 One of the most important of these reactions forms a single oxygen atom o It eventually produces ozone that damages plant and animal tissues and building material paint plastic rubber Step 1 Nitrogen dioxide N02 UV 9 nitric oxide NO single atom of oxygen O Step 2 Oxygen atom O oxygen gas Oz 9 ozone O3 0 Ozone is strong oxidant and damages vegetation paints plastics rubber and sensitive tissues in eyes and lungs Air toxins Hazardous air pollutants HAPs are monitored by EPA These chemicals include carcinogens neurotoxins mutagens teratogens endocrine system disrupters and other highly toxic compounds Twenty of the most persistent bioaccumulative compounds require special reporting and management they remain in the ecosystem for a long time Most of these chemicals are metal compounds chlorinated hydrocarbons or volatile organic compounds The best source of information is the Toxics Release Inventory TRI collected by the EPA What is TRI The Toxics Release Inventory TRI is a publicly available EPA database that contains information on toxic chemical releases and other waste management activities reported annually by certain covered Industry groups as well as federal facilities This inventory was established under the Emergency Planning and Community Rightto Know Act of 1986 EPCRA and expanded by the Pollution Prevention Act of 1990 httpwwwepagovtri Unconventional pollutants All are anthropogenic Aesthetic degradation includes undesirable changes in the atmosphere like odors loud noise and bright lights Many are not life threatening but reduce the quality of life e g noise and bad odors Indoor air pollution Concentrations of air pollutants are often higher than outdoors Sometimes up to 70 times higher e g chloroform benzene carbon tetrachloride formaldehyde and styrene Formaldehyde is used in more than 3000 products including building material like insulating foam particle boards wafer board etc Tobacco smoking is the most serious indoor pollutant in the U S A Combustion smoke produced by burning wood charcoal and dried dung is the most serious pollutant in many poor areas of the world Other household pollutants are radon vinyl chloride and asbestos CLIMATE TOPOGRAPHY AND ATMOSPHERIC PROCESSES They play a role in the transport concentration dispersal and removal of pollutants Inversions Temperature inversions occur when a layer of warmer air overlays a layer of cooler air It is a reversal of normal temperature patterns in the lower atmosphere Normally the atmosphere is heated from below by heat by solar radiation absorbed by the earth surface and the released to the air in contact with it Warm air rises o A warm air mass moving over a colder one can quotshut offquot the convection effects keeping the cooler air mass trapped below see capping inversion lt commonly occurs at night when solar heating ceases the surface cools by radiation and cools the immediately overlying atmosphere httpwww answers quot 39 quot inversion 0 Temperature inversion may occur during the passage of a cold front or result from the invasion of sea air by a cooler onshore breeze Overnight radiative cooling of surface air often results in a nocturnal temperature inversion that is dissipated after sunrise by the warming of air near the ground httpwww answers quot 39 quot rsion Dust domes and heat islands 0 High level of concrete and glass allows rainfall to run off quick and increase heat absorption during the day and radiation at night 0 Tall buildings create convective updrafts that sweep pollutants into the air 0 Heat air masses over the cities concentrate pollutants in a quotdust domequot 0 Dust and aerosols seem to trigger lightning strikes Longrange transport 0 Air pollution from heavily industrialized regions of America and Europe is transported by circumpolar winds to the Arctic o Volatile compounds evaporate from warm areas travel through the atmosphere then condense and precipitate in cooler regions 0 Over several years contaminants accumulate in the coldest places generally at high latitudes where they bioaccumulate in food chains 0 It contains aerosols of sulfates vanadium manganese lead soot dust etc o Tracing the source is difficult o It is often an international sensitive problem 0 Some places traditionally considered clean like Greenland Antarctica and Samoa have heavy metals pesticides and radioactive chemicals in their air Stratospheric ozone o In the upper atmosphere ozone screens UV radiation 0 Without this screen organisms will be subjected to harmful radiation that could kill or cause genetic damage 0 Ozone depletion has been occurring at least since the 1960s 0 In the spring of 1997 10 of the ozone worldwide was destroyed All the ozone between 14 and 20 km altitude was destroyed in an area of 22 million km2 o For every 1 loss of ozone there is a 2 increase of UV reaching the earth surface 0 Chlorofluorocarbons CFC destroy the ozone layer 0 Freon is a chlorofluorocarbon it is cheaply produced nontoxic nonflammable chemically inert and with many applications 0 In 1989 eighty nations agreed to phase out the production of CFC by the end of the century EFFECTS OF AIR POLLUTION Human health Sulfur oxides nitrogen oxides and ozone are irritants and damage the delicate tissues in the eyes and respiratory passages Carbon monoxide binds to hemoglobin and prevents oxygen transport Bronchitis is a persistent inflammation of the air passages that become constricted creating cough and muscle spasms Emphysema is an irreversible lung disease in which the respiratory passages become permanently constricted and the alveoli damaged 0 Breathing becomes difficult and not enough oxygen is absorbed into the blood Plant pathology There are two ways in which air pollution can damage plants 1 Pollutants can be directly toxic damaging tissues 2 Some pollutants act as metabolic regulators when absorbed by plant cells and disrupt the normal metabolism of the cells eg ethylene Certain combinations have synergistic effects like ozone and sulfur dioxide Important consequences for agriculture and forestry Acid deposition Acid deposition causes changes in soil and water pH forest damage destruction of buildings and monuments and visibility reduction Sulfuric acid and nitric acid are produced in the atmosphere Fog snow mist and rain deposit atmospheric pollutants changing the pH the soil and bodies of water Many aquatic organisms are sensitive to pH changes and disappear Egg and fish fry of many species of fish are especially sensitive to a pH of 5 or below Their death causes a disruption of the food chain Sweden has about 18000 lakes so acidic that they cannot support life Air pollution and deposition of atmospheric acids thought to be the leading causes of forest destruction in many areas European forests are dying at an alarming rate High altitude forests on the Appalachian mountains have been affected or killed by air pollution e g spruce forests in Vermont and North Carolina Buildings and monuments made of limestone and marble are damage very fast by acid rain Paintings statues stained glass windows are affected by acid Oxidation and acid damage paint rubber and steel Foul air obscures the sky above industrialized cities Haze can reduce visibility up to 80 AIR POLLUTION CONTROL Mix and dilute Dilution is the solution to pollutionquot The best method to reduce pollution is to minimize pollution We have made considerable progress in designing pollutioncontrol equipment to reduce the major conventional pollutants I I 1 L There are many types of filters catalysts fuel and new burning techniques for controlling air pollution Electrostatic precipitators give an electrical charge to particles as they travel in the effluent stream and this causes the particle to migrate and get deposited on the plate with the opposite charge Catalytic converters oxidize sulfur oxides to produce sulfuric acid elemental sulfur and ammonium sulfate These products have a commercial value Several methods use limestone to remove sulfur for burning coal Sulfur oxides react with calcium in the limestone to produce calcium sulfate and other compounds of calcium and sulfur Nitrogen oxides can be reduced by 50 by carefully controlling the flow of air and fuel Hydrocarbons and volatile organic compounds are produced by incomplete combustion of fuels or by solvent evaporation from chemical factories paints dry cleaning plastic manufacturing printing and other industrial processes Close system that prevent the escape of fugitive gases can reduce many emissions eg PCV in automobiles Alternative sources of energy like wind and solar power are preferable to the burning of fossil fuels and are becoming economically competitive CLEAN AIR LEGISLATION 1 The Clean Air Act of 1963 was the firs US legislation aimed at air pollution control o It set up the National ambient Air Quality Standards or NAAQS 2 Extensive amendments were made in 1970 o Identified the criteria pollutants 0 Established national ambient quality standards 0 Primary standards aim to protect human health 0 Secondary standards aim to protect crops climate etc 3 In 1990 the Clean Air Act was rewritten and updated Important provision dealt with cutting the emission standards for Acid rain urban smog toxic air pollutants 189 instead of 7 as before and marketing pollution rights CFC and carbon tetrachloride will be phased out by the year 2000 in order to protect the ozone layer Toxic organic compounds are regulated by standards that specify the manufacturing facilities storage sampling methods etc o Nitrogen oxide emissions improved standards for SUV and other vehicles 4 Clear Skies plan o The plan eliminated the new source reviewquot which was implemented in 1977 Congress agreed to exempt existing equipment from new pollution limits with the stipulation that when they upgraded most stringent rules would apply It resulted in keeping old facilities operating because they were exempted from pollution control 0 According to the Bush administration to determine which facility is old and which is new is too cumbersome This prompted the EPA to stop the new source review plan 0 Nine northeastern States that receive the pollutants from Midwest factories have sued the EPA for abandoning the plan to combat dirty air 0 President Bush continues to resist calls for expensive greenhouse gas restrictions Diffuse sources like aerosol hair spray deodorants charcoal lighter fluids gasolinepowered lawnmowers fireplaces volatile paints and solvents etc contribute to air pollution CURRENT CONDITIONS AND FUTURE PROSPECTS In the US air quality has improved dramatically in the last 30 years Between 1970 and 1994 emissions of all criteria in the United States have decreased except for nitrogen oxides 0 Lead has decreased by 98 0 S02 is down by 32 o Particulates have been reduced by 78 Baltimore MD and Birmingham AL have a very high level of particle emission Los Angeles Anaheim and Riverside in southern California are within the extreme urban smog category Cities like Baltimore Chicago New York Houston Philadelphia and San Diego have continuing problems of air pollution and do not meet the standard set by the NAAQS About 80 of the US now meets the NAAQS goals Sweden and West Germany cut their sulfur emissions by 23 between 1970 and 1985 Many large cities around the world have improved their air quality Some of the most serious problems exist are 0 Air pollution is particularly bad in the Czech Republic Slovakia and southern Poland 0 Life expectancy in some industrial towns of Romania and the Czech Republic is as much as 10 years lower than the national average Foul air is blamed for this decrease in life expectancy 0 Mexico City and Santiago de Chile are notorious for their fowl air 0 China has done nothing significant to improve the polluted air in its cities 0 The high incidence of lung cancer in Shanghai is thought to be linked to air pollution Bad or clean air in US cities and others mpwwwenvironmentaldefenseorgcleanairforlifecfmsubnavaivc 50cities httpwwwscorecardorg httpwwwnationmastercomfactsphg httpwwwclimatehotmaporgcamericahtml Top polluters httpwwwscorecardorgrankingrank facilitiestchow manv100ampdrop down nameAirreIeasesamp ps state codeEntire Unitedm quot 39 2Areportinqsectors Shelby county httpwwwscorecardorqcommunitvindextczip code38104ampset communitv zipcod e cookie ptampx17ampy4 INSECTS Entomology is the study of insects There are well over 1000000 different known species of insects in the world and some experts estimate that there might be as many as 10000000 They are divided up into 32 orders depending on whose taxonomic system you use of which the largest is the Beetles Coleoptera with 125 different families around 500 000 species In fact one in every four animals on this planet is a beetle INSECT BODY PARTS The exoskeleton is the hard body covering of insects sometimes referred popularly as the shell of the insect It protects the internal organs and provides anchorage for the muscles of the insect The most visible parts of the body of an adult insect are the head the antennae the mouthparts the thorax the wings the legs and the abdomen Head The head is the anterior of the three body regions of an adult insect It bears the eyes usually a pair of compound eyes the antennae and the mouthparts Mouthparts The mouthparts of adult insects can be of different types In many species they are of the chewing type for example in grasshoppers and beetles Others have sucking mouthparts for example shaped like stylets in bugs and aphids or shaped like a coiled tongue in butter ies and moths The different types of mouthparts determine how the insect feeds Antennae The head of most adult insects bears a pair of antennae Insects use the antennae to detect odors or they use them as tactile touch organs Antennae are very variable in form and size Thorax The thorax is the middle of the three body regions of an adult insect It is composed of 3 segments It bears 3 pairs of legs one on each segment and usually 2 pairs of wings Some insects have only 1 pair of wings Legs Adult insects have 6 legs Each of the segments of the thorax bears 1 pair of legs The legs are segmented Often the last segment of the leg bears a small claw In some insects the legs are specially adapted for jumping Wings Most adult insects have 2 pairs of wings but some for example ies have only 1 pair of wings Usually the wings are membranous but in some insects they can be leathery or hard Sometimes the wings bear hairs or small scales Abdomen The abdomen is the posterior ofthe three body regions of an adult insect It is composed of 11 segments The abdomen bears the external genitalia of the insect In female insects these consist of an ovipositor METAMORPHOSIS Metamorphosis is the series of developmental changes an insect passes in its growth from the egg to the adult Metamorphosis requires a change in form habit food and size Growth requires molting During molting the insect sheds its eXternal skeleton During the short period its skin remains soft and the new skeleton is formed the insect grows rapidly Simple metamorphosis In simple metamorphosis the wings develop eXternally during the larval stages The larval stages which are called nymphs look very similar to the adult insect There is no pupal stage Egg nymph l nymph 2 nymph 3 etc a adult Other names used for the immature stage or nymph are larva naiad and instar The nymph stage may be divided into several instars The nymph resembles the adult form and there is no change in food requirements At each step of growth the exoskeleton is molted Com plete metamorphosis In a complete metamorphosis the wings develop internally during the larval stages The larval stages look quite different from the adult Between the last larval stage and the adult stage there is a pupal stage which usually is inactive Egg larva pupa adult MOSQUITO LIFE CYCLE All mosquitoes have one common requirementthey need water to complete their life cycle Some mosquitoes lay individual eggs on the sides of tree holes or discarded containers or in depressions in the ground that will hold water The eggs can lay dormant for several years Some eggs will hatch when they are ooded by rainfall Several ooding and drying cycles are usually required for all of the eggs to hatch that are laid by a particular female mosquito Other mosquitoes lay eggs directly on the surface of water The eggs are attached to one another to form a raft or the individual eggs oat on the water These eggs hatch in 2448 hours releasing larvae that are commonly called quotwrigglersquot because you can often see the larvae wriggling up and down from the surface of the water Generally the larvae feed on microorganisms and organic material in the water but some mosquitoes prey on the larvae of other mosquito species and are regarded to be bene cial In about 710 days after eggs hatch larvae change to the pupal or quottumblerquot stage in preparation for adult life Female mosquitoes begin to seek an animal to feed on several days after emerging from water Male mosquitoes mate with females one to two days after the females emerge Males do not bite but they do feed on plant juices MOSQUITO BREEDING SITES Since mosquitoes need water to complete their life cycle the source of a mosquito problem can be just about anywhere that water can collect Farm ponds and lakes usually do not breed mosquitoes if they contain sh and are free of weeds algae or oating debris in which mosquito larvae can hide Municipal and farm animal waste lagoons may also become breeding sites Permanent natural bodies of water such as swamps usually contain a large array of predatory insects and sh that keep mosquitoes from reaching nuisance levels Our activities may create mosquito breeding sites or increase the production of mosquitoes in natural bodies of water 1 Road building and maintenance often impedes the drainage of runoff from rainfall creating a mosquito breeding site 2 Clogged drainage ditches along roads can become productive mosquito breeding sites 3 Logging and construction activities often leave tire ruts in the soil These depressions are ideal breeding sites for quot oodwaterquot mosquito species 4 Around the home object such as bird baths boats canoes discarded tires plant pots and other such objects collect rainwater and allow mosquitoes to breed literally right in our own backyard You can help reduce mosquito populations by eliminating these breeding sites lRemove discarded containers from your property Empty containers collect water 2Flush out the water in bird baths every few days 3Store boats canoes and other objects so that they do not collect rainwater 4Keep rain gutters free of leaves and other debris that prevent water from draining 5Correct drainage problems in your yard where rainwater might collect 6Correct or report drainage problems in ditches along residential roadways 7Check ower pots for excess water 8Clear debris from drainage ditches so that water does remain for long periods of time MOSQUITO CONTROL SUMMARY Mosquitoes need water to complete their life cycle They can breed in almost any source of water Pesticides are only a shortterm solution to nuisance mosquito problems Solving the problem effectively and safely requires 1 Proper identi cation of the mosquito species 2 Obtaining information about the biology and behavior of these particular species 3 Locating and eliminating breeding sites particularly arti cial sites that may be as close as your own backyard 4 Using appropriate chemical controls measures including personal protection Most mosquito species survive the inter or overwinter in the egg stage awaiting the spring thaw when waters warm and the eggs hatch A few important species spend the winter as adult mated females resting in protected cool locations such as cellars sewers crawl spaces and well pits With warm spring days these females seek a blood meal and begin the cycle again Only a few species can overwinter as larvae Mosquitohome diseases such as malaria and yellow fever have plagued civilization for thousands of years Organized mosquito control in the United States has greatly reduced the incidence of these diseases However there are still a few diseases that mosquitoes in New Jersey can transmit including Eastern Equine Encephalitis and St Louis Encephalitis The frequency and eXtent of these diseases depend on a compleX series of factors INSECTS Entomology is the study of insects There are well over 1000000 different known species of insects in the world and some experts estimate that there might be as many as 10000000 They are divided up into 32 orders depending on whose taxonomic system you use of which the largest is the Beetles Coleoptera with 125 different families around 500 000 species In fact one in every four animals on this planet is a beetle INSECTS INSECT BODY PARTS The exoskeleton is the hard body covering of insects sometimes referred popularly as the shell of the insect It protects the internal organs and provides anchorage forthe muscles of the insect The most visible parts of the body of an adult insect are the head the antennae the mouthparts the thorax the wings the legs and the abdomen Head The head is the anterior of the three body regions of an adult insect It bears the eyes usually a pair of compound eyes the antennae and the mouthparts Mouthparts The mouthparts of adult insects can be of different types In many species they are of the chewing type for example in grasshoppers and beetles Others have sucking mouthparts for example shaped like stylets in bugs and aphids or shaped like a coiled tongue in butterflies and moths The different types of mouthparts determine how the insect feeds Antennae The head of most adult insects bears a pair of antennae lnsects use the antennae to detect odors or they use them as tactile touch organs Antennae are very variable in form and size Thorax The thorax is the middle of the three body regions of an adult insect It is composed of 3 segments It bears 3 pairs of legs one on each segment and usually 2 pairs of wings Some insects have only 1 pair of wings Legs Adult insects have 6 legs Each of the segments of the thorax bears 1 pair of legs The legs are segmented Often the last segment of the leg bears a small claw In some insects the legs are specially adapted for jumping Wings Most adult insects have 2 pairs of wings but some for example flies have only 1 pair of wings Usually the wings are membranous but in some insects they can be leathery or hard Sometimes the wings bear hairs or small scales Abdomen The abdomen is the posterior of the three body regions of an adult insect It is composed of 11 segments The abdomen bears the external genitalia of the insect In female insects these consist of an ovipositor METAMORPHOSIS Metamorphosis is the series of developmental changes an insect passes in its growth from the egg to the adult Metamorphosis requires a change in form habit food and size Growth requires molting During molting the insect sheds its external skeleton During the short period its skin remains soft and the new skeleton is formed the insect grows rapidly Simple metamorphosis In simple metamorphosis the wings develop externally during the larval stages The larval stages which are called nymphs look very similar to the adult insect There is no pupal stage Egg nymph 1 nymph 2 nymph 3 etc a adult Other names used for the immature stage or nymph are larva naiad and instar The nymph stage may be divided into several instars The nymph resembles the adult form and there is no change in food requirements At each step of growth the exoskeleton is molted Complete metamorphosis In a complete metamorphosis the wings develop internally during the larval stages The larval stages look quite different from the adult Between the last larval stage and the adult stage there is a pupal stage which usually is inactive Egg larva pupa adult MOSQUITO LIFE CYCLE All mosquitoes have one common requirementthey need water to complete their life cycle Some mosquitoes lay individual eggs on the sides of tree holes or discarded containers or in depressions in the ground that will hold water The eggs can lay dormant for several years Some eggs will hatch when they are flooded by rainfall Several flooding and drying cycles are usually required for all ofthe eggs to hatch that are laid by a particular female mosquito Other mosquitoes lay eggs directly on the surface of water The eggs are attached to one another to form a raft or the individual eggs float on the water These eggs hatch in 2448 hours releasing larvae that are commonly called quotwrigglersquot because you can often see the larvae wriggling up and down from the surface of the water Generally the larvae feed on microorganisms and organic material in the water but some mosquitoes prey on the larvae of other mosquito species and are regarded to be beneficial In about 710 days after eggs hatch larvae change to the pupal or quottumblerquot stage in preparation for adult life Female mosquitoes begin to seek an animal to feed on several days after emerging from water Male mosquitoes mate with females one to two days after the females emerge Males do not bite but they do feed on plantjuices MOSQUITO BREEDING SITES Since mosquitoes need water to complete their life cycle the source of a mosquito problem can be just about anywhere that water can collect Farm ponds and lakes usually do not breed mosquitoes if they contain fish and are free of weeds algae or floating debris in which mosquito larvae can hide Municipal and farm animal waste lagoons may also become breeding sites Permanent natural bodies of water such as swamps usually contain a large array of predatory insects and fish that keep mosquitoes from reaching nuisance levels Our activities may create mosquito breeding sites or increase the production of mosquitoes in natural bodies of water 1 Road building and maintenance often impedes the drainage of runoff from rainfall creating a mosquito breeding site 2 Clogged drainage ditches along roads can become productive mosquito breeding sites 3 Logging and construction activities often leave tire ruts in the soil These depressions are ideal breeding sites for quotfloodwaterquot mosquito species 4 Around the home object such as bird baths boats canoes discarded tires plant pots and other such objects collect rainwater and allow mosquitoes to breed literally right in our own backyard You can help reduce mosquito populations by eliminating these breeding sites 1Remove discarded containers from your property Empty containers collect water 2Flush out the water in bird baths every few days 3Store boats canoes and other objects so that they do not collect rainwater 4Keep rain gutters free of leaves and other debris that prevent water from draining 5Correct drainage problems in your yard where rainwater might collect 6Correct or report drainage problems in ditches along residential roadways 7Check flower pots for excess water 8Clear debris from drainage ditches so that water does remain for long periods oftime MOSQUITO CONTROL SUMMARY Mosquitoes need water to complete their life cycle They can breed in almost any source of water Pesticides are only a shortterm solution to nuisance mosquito problems Solving the problem effectively and safely requires Proper identification of the mosquito species Obtaining information about the biology and behavior of these particular species Locating and eliminating breeding sites particularly artificial sites that may be as close as your own backyard 4 Using appropriate chemical controls measures including personal protection PM Most mosquito species survive the inter or overwinter in the egg stage awaiting the spring thaw when waters warm and the eggs hatch A few important species spend the winter as adult mated females resting in protected cool locations such as cellars sewers crawl spaces and well pits With warm spring days these females seek a blood meal and begin the cycle again Only a few species can overwinter as larvae Mosquitoborne diseases such as malaria and yellow fever have plagued civilization for thousands of years Organized mosquito control in the United States has greatly reduced the incidence ofthese diseases However there are still a few diseases that mosquitoes in New Jersey can transmit including Eastern Equine Encephalitis and St Louis Encephalitis The frequency and extent of these diseases depend on a complex series of factors ARBOVIRUSES Arthropodborne viruses termed quotarbovirusesquot are viruses that are maintained in nature through biological transmission between susceptible vertebrate hosts by bloodfeeding arthropods mosquitoes sand flies ceratopogonids quotnoseeumsquot and ticks Vertebrates can become infected when an infected arthropod bites them to take a blood meal The term 39arbovirus39 has no taxonomic significance Arboviral encephalitis can be prevented in two major ways personal protective measures to reduce contact with mosquitoes and public health measures to reduce the population of infected mosquitoes in the environment COMMON DISEASES SAINT LOUIS ENCEPHALITIS Encephalitis An inflammation of brain tissue producing an acute febrile illness almost always viral in origin It may range from mild to life threatening Depending on the extent and area of inflammation symptoms can include fever delirium and confusion progressing to unconsciousness cranial nerve palsies paresis paralysis involuntary movement and abnormal reflexes lntracranial pressure ICP may become elevated Often an encephalitis will involve the meninges as well 0 The first recognized cases of Saint Louis Encephalitis SLE occurred in 1933 in the city of St Louis Hence the origin of the name Saint Louis Encephalitis SLE is a virally induced disease Since 1933 several outbreaks of SLE infection have occurred in North America and some Caribbean islands In recent years epidemics of up to 2000 cases have occurred in both urban and suburban areas in the Ohio Mississippi river basin eastern and central Texas and Florida o The virus is transmitted to man and other hosts by shortlived mosquitoes of the genus Culex These mosquitoes are very common in the USA Humans and most other mammals are very poor carriers of SLE Birds also carry the virus When a Culex mosquito bites a bird carrying this virus the virus is transmitted to the mosquito Likewise if a mosquito carrying the virus bites a bird the virus is transmitted to the bird In this manner the virus circulates between birds and mosquitoes But the virus adversely affects neither the bird nor mosquito If an infected mosquito bites a human then the virus is transmitted to the human 0 In the United States SLE is the most common of all mosquito borne cases of encephalitis Whenever conditions favor the proliferation of Culex there is an increased risk that an outbreak of SLE will occur In the United States these conditions include above average summer temperatures and a period of deficient rainfall followed by heavy rains These conditions are most favorable for producing stagnant pools of water which are ideal for Culex to breed in o Epidemics tend to occur sporadically and most often take place between July and September Both the very young and the old have the greatest risk of becoming seriously iii if bitten by an infected mosquito The overall mortality rate for SLE is 9 but it approaches 30 in those over age 65 EASTERN EQUINE ENCEPHALITIS Eastern Equine Encephalitis EEE is a mosquitoborne viral disease As the name suggests EEE occurs in the eastern half of the US Because of the high case fatality rate it is regarded as one of the more serious mosquitoborne diseases in the United States TRANSMISSION What is the EEE transmission cycle How do people become infected with EEE virus EEE virus is transmitted to humans through the bite of an infected mosquito The main EEE transmission cycle is between birds and mosquitoes Several species of mosquitoes can become infected with EEE virus The most important mosquito in maintaining the enzootic animalbased in this case birdmosquitobird transmission cycle is Culiseta melanura Horses can become infected with and die from EEE virus infection ETlOLOGlC AGENT What causes EEE Eastern equine encephalitis virus is a member of the family Togaviridae genus Alphavirus Closely related to Western and Venezuelan equine encephalitis viruses HUMAN CLINICAL FEATURES What type of illness can occur Symptoms range from mild flulike illness to encephalitis inflammation of the brain coma and death The EEE case fatality rate the of persons who develop the disease who will die is 35 making it one of the most pathogenic mosquitoborne diseases in the US It is estimated that 35 of people who survive EEE will have mild to severe neurologic deficits INCIDENCE How many and where have human disease cases occurred 200 confirmed cases in the US 1964present Average of 4 casesyear with a range from 014 cases States with largest number of cases are Florida Georgia Massachusetts and New Jersey The enzootic animalbased transmission cycle is most common to coastal areas and freshwater swamps Human cases occur relatively infrequently largely because the primary transmission cycle takes place in swamp areas where populations tend to be limited RISK GROUPS Who is at risk for developing EEE Residents of and visitors to endemic areas areas with an established presence of the virus People who engage in outdoor work and recreational activities Persons over age 50 and younger than age 15 seem to be at greatest risk for developing severe disease PREVENTION How can people avoid infection with EEE virus A vaccine is available to protect equines People should avoid mosquito bites by employing personal and household protection measures such as using insect repellent containing DEET wearing protective clothing taking precautions from dusk to dawn when mosquitoes are most likely to bite and controlling standing water that can provide mosquito breeding sites Risk of exposure to infected mosquitoes increases as population expands into areas with an established presence of the virus CHALLENGES There is no licensed vaccine for human use There are no effective therapeutic drugs Unknown overwintering cycle Control measures expensive Limited financial support of surveillance and prevention httpWVIM cdc govncidoddvbidarboreeefact htm Meningitis an inflammation of the meninges protective membranes surrounding the CNS Bacteria fungi or viruses can all potentially infect the meninges hence you can have bacterial meningitis or viral meningitis Viral meningitis is referred to as aseptic meningitis WESTNILE VIRUS GENERAL West Nile virus has been described in Africa Europe the Middle East west and central Asia Oceania subtype Kunjin and most recently North America In late summer 1999 the first domestically acquired human cases of West Nile WN encephalitis were documented in New York US The 2002 WNV epidemic and epizootic resulted in reports of 4156 reported human cases of WN disease including 2942 meningoencephalitis cases and 284 deaths 16741 dead birds 6604 infected mosquito pools and 14571 equine cases The 2002 WNV epidemic was the largest recognized arboviral meningoencephalitis epidemic in the Western Hemisphere and the largest WN meningoencephalitis inflammation of the spinal cord and brain epidemic ever recorded Significant human disease activity was recorded in Canada for the first time and WNV activity was also documented in the Caribbean basin and Mexico In 2002 4 novel routes of WNV transmission to humans were documented for the first time 1 blood transfusion 2 organ transplantation 3 transplacental transfer 4 breastfeeding As November 25 2003 Tennessee 25 reported cases 1 death The State with the highest incident of WN virus is Colorado with 2477 reported cases and 45 deaths followed by Nebraska 1727 cases 21 deaths and South Dakota 1001 cases 13 deaths These numbers reflect both mild and severe human disease cases that have been reported to ArboNet by state and local health departments during 2003 ArboNet is the national electronic surveillance system established by CDC to assist states in tracking West Nile virus and other mosquitoborne viruses Of the 8567 cases reported as of the above date 5686 cases 66 were reported as West Nile Fever milder disease 2505 29 were reported as West Nile meningitis or encephalitis severe disease and 3764 were clinically unspecified 11 4 httpWWW cdcw yaw m whtm TRANSMISSION CYCLE West Nile WN virus is amplified during periods of adult mosquito bloodfeeding by continuous transmission between mosquito vectors and bird reservoir hosts lnfectious mosquitoes carry virus particles in their salivary glands and infect susceptible bird species during bloodmeal feeding Competent bird reservoirs will sustain an infectious viremia virus circulating in the bloodstream for 1 to 4 days after exposure after which these hosts develop lifelong immunity A sufficient number of vectors must feed on an infectious host to ensure that some survive long enough to feed again on a susceptible reservoir host People horses and most other mammals are not known to develop infectiouslevel viremias very often and thus are probably quotdeadendquot or incidentalhosts In the United States infected mosquitoes primarily members of the Culex species transmit West Nile virus HUMANS West Nile Fever is a mild disease in people characterized by flulike symptoms West Nile fever typically lasts only a few days and does not appear to cause any longterm health effects More severe disease due to a person being infected with West Nile virus can be West Nile encephalitis West Nile meningitis or West Nile meningoencephalitis o Encephalitis refers to an inflammation of the brain meningitis is an inflammation of the membrane around the brain and the spinal cord 0 Meningoencephalitis refers to inflammation of the brain and the membrane surrounding it BIRDS West Nile virus has been detected in dead birds of at least 138 species Although birds particularly crows and jays infected with WN virus can die or become ill most infected birds do survive There is no evidence that a person can get WN virus from handling live or dead infected birds Persons should avoid barehanded contact when handling any dead animals and use gloves or double plastic bags to place the bird carcass in a garbage bag or contact their local health department for guidance DOGS AND CATS West Nile virus does not appear to cause extensive illness in dogs or cats There is a single published report of WN virus isolated from a dog in southern Africa Botswana in 1982 West Nile virus was isolated from a single dead cat in 1999 A serosurvey in New York City of dogs in the 1999 epidemic area indicated that dogs are frequently infected Nonetheless disease from WN virus infection in dogs has yet to be documented There is no documented evidence of persontoperson or animaltoperson transmission of WN virus HORSES Available data suggest that most horses infected with West Nile virus recover results of investigations indicate that West Nile virus has caused deaths in horses in the United States http39lvwwcdca quot 39 39 quot quot 39 quot 39 htm httplVWW cdc govncidoddvbidwestnileqampa htm Chapter3 MATTER ENERGY AND LIFE Every organism uses matter and energy from its environment and transforms them into structures and processes that make life possible The physical and chemical principles that govern the universe also govern the composition and metabolic processes of living organisms Organisms are made of inorganic compounds and organic compounds MATTER AND FUNDAMENTAL PARTICLES Matter is anything that has mass and takes up space Weight is a measurement of the pull of the Earth39s gravity on an object 0 Weight changes with distance 0 Mass of an object is constant regardless of distance Matter is transformed and recombined but it doesn t disappear This is the principle of conservation of matter Elements are the simplest substances They cannot be broken down into simpler substance by chemical reactions An atom is the simplest portion of an element that retains its chemical properties Each element has its own characteristic atom represented by a chemical symbol Subatomic particles protons neutrons and electrons The number of protons atomic number identifies the atom Protons carry a positive electrical charge neutrons are electrically neutral and electrons are ative The number of protons and neutrons determines the mass of the atom atomic mass The mass of the electron is 11800 of the mass of a proton or neutron and it is disregarded in calculating the atomic mass of an atom Isotopes of an element are atoms that have the same number of protons and different number of neutrons Some isotopes are radioactive and are called radioisotopes CHEMICAL BONDS Atoms may combine chemically bond to form molecules Molecules of an element have atoms of the same kind eg H2 N2 A chemical compound is made of different type atoms eg H20 CaOH2 Molecular formulas describe the atomic composition of one molecule of the compound The forces that hold atoms together are called chemical bonds Each bond contains certain amount of energy called chemical energy This energy can be released in certain chemical reactions Bonds vary in stability Some are stable and form strong bonds that require a lot of energy to break apart Others are weak and break with very little energy Atoms share electrons when they form covalent bonds The carbon atom can form four covalent bonds making it possible to make the many complex molecules found in living organisms Atoms with equal number of protons and neutrons are electrically neutral IONS ACIDS AND BASES Atoms can loose or gain electrons and become electrically charged in the process These electrically charged atoms or molecules are called ions Atoms that gain an electron become negative 1 charge and are called negative ions We say this atom is reduced Atoms that loose an electron become positive 1 charge and are called positive ions We say this atom is oxidized Example HCl can split into H and Cl39 Here the hydrogen atom gave up one electron to the chlorine atom and became positive which is 1 or H the chlorine atom gained one electron and its negative charges went up by one It is now 1 or Cl39 Compounds that release hydrogen ions are called acids and those that combine readily with hydrogen ions are called bases The pH scale describes the number of free hydrogen ions in a solution 0 A pH of 7 is neutral a pH less than 7 is acidic and above 7 is basic 0 The scale is logarithmic which means that a pH6 represent ten times more hydrogen ions in solution than pH7 Some ions like those of Na and Cl39 can attract each other and form ionic bonds These bonds could be very strong like those formed by sodium chloride table salt Water molecules form hydrogen bonds These bonds give water some of its important chemical and physical characteristics Substances that release hydrogen ions H in water are called acids Substances that readily bond with hydrogen ions H are called bases or alkaline substances The pH scale measures the concentration of hydrogen ions protons in a solution It is based on the negative logarithm of its concentration of H Example 10396 concentration of H has a pH of 6 a concentration of 10395 has a pH of 5 which is ten times stronger than pH 6 Notice that the concentration of H increases as pH declines A pH of 10 has an acid concentration of 103910 and a hydroxide concentration of 104 This is a basic or alkaline solution 7 is neutral Below 7 is acid and above 7 is basic or alkaline ORGANIC COMPOUNDS Organic compounds are so named because they were thought to be produced only by living organisms Organic compounds contain carbon There are simple carbon compounds that are considered inorganic especially if they do not contain hydrogen eg C0 C02 Carbon atoms form chains and rings that form different organic molecules found in the body of plants and animals These are called biomolecules Lipids proteins carbohydrates and nucleic acids are the principal biomolecules Lipids fats and oils are important components of cell membranes Carbohydrates are sources of energy and also form part of supporting structures eg cellulose forms the cell wall of plants Proteins are involved in the structure and function of cells eg structure of cell membrane enzymes are proteins Nucleic acids are very complex molecules They store genetic information and direct the life processes CELLS 1 Cells are the basic unit of structure and function of all living things 2 All cells come from preexisting cells All cells have a similar organization 0 semipermeable plasma membrane that surrounds the cell 0 internal structures called organelles 0 DNA that contains the genetic material Organisms may be unicellular or multicellular A membrane the plasma membrane surrounds cells The plasma membrane is made of lipids proteins and a few carbohydrates The plasma membrane regulates what enters and leaves the cell Inside the cells there are quotorganellesquot that perform different functions and permit the cell to operate Enzymes are proteins that act as catalysts These catalysts are specialized and permit life functions to take place Metabolism is the sum of all the enzymatic reactions taking place in the body of an organism ENERGY Basic concepts Energy is the capacity to do work 0 Energy is measured in joules One joule can move one kilogram one meter 0 1 kg 22pounds Work is any change in the state or motion of an object Energy can change form Kinetic energy is the energy of motion Potential energy is stored energy It depends on the location and structure of matter 0 Chemical energy stored is food eg sugars is a form of potential energy Heat is the energy that can be transferred between objects of different temperature It is the total amount of kinetic energy in a substance that its bulk is not moving Temperature is the measure of the energy of motion of molecules 0 A substance can have high heat content and low temperature 0 Low average molecular speed 0 Large mass with many moving molecules and atoms Thermodynamics Thermodynamics regulates energy transfer Matter is recycled It changes forms but it is neither created nor destroyed 1 First law of thermodynamics 0 Energy of the universe is constant 0 Energymass cannot be created nor destroyed 0 Energy may be transformed eg from a energy in a chemical bond to heat energy 2 Second law of thermodynamics When energy is converted from one form to another some of the usable energy is converted to heat and is dispersed in the surroundings At every step of energy transformation there is a loss of energy capable to do work No one process that requires energy conversion is 100 efficient All natural systems then to go from a state of order to toward a state of increasing disorder Entropy or amount of disorder increases reflecting the loss of energy There is less energy available at the end of a process than at the beginning APPLICATION To ORGANISMS Organisms are highly organized both structurally and functionally Constant maintenance is required to keep this organization and a constant supply of energy is required to maintain these processes Energy is used by the cell to do work If the energy supply is depleted the cell will die ENERGY FOR LIFE The sun is the ultimate source of energy for living organisms A few ecosystems are based on energy derived from inorganic substances and the earth molten interior Extremophiles Extremophiles are organisms that live in severe conditions Deepsea hydrothermal vents provide energy to an ecosystem that lives in total darkness and under tremendous pressure The energy source for this ecosystem is provided by inorganic molecules like hydrogen sulfide and hydrogen gas through a process called chemosynthesis Most of these extremophiles are single celled organisms called archaea Archaea are considered to be very primitive organisms and the conditions under which they live are thought to be similarto those in which life first evolved Green plants get energy from the sun The sun produces warmth and light both of which are needed for living organisms 0 Most organisms live within a narrow temperature range 0 Light is composed of particles of energy that travel as waves 0 Light is part of the electromagnetic spectrum the entire range of electromagnetic radiation Of the solar radiation that reaches the earth s surface 45 is visible light 45 is infrared radiation and 10 is ultraviolet radiation 0 30 is reflected back into space 0 20 is absorbed by the atmosphere 0 50 is absorbed by ground water and vegetation Less than 1 of the absorbed energy is used in photosynthesis This small percentage is the energy base for all life on the biosphere HOW PHOTOSYNTHESIS CAPTURES ENERGY Photosynthesis converts radiant energy into useful high quality chemical energy in the bonds that hold together organic molecules foodl Photosynthesis can use mostly red and blue light Green is reflected Every point of the earth is illuminated for six months of the year 0 Continuously during 6 months the polar summers o Alternating 12 hours of darkness with 12 hours light in the tropics Sunrays strike the earth obliquely in the higher latitudes Sunlight is responsible for the flow of wind ocean currents weather patterns and the hydrological cycle Photosynthesis is the conversion of light energy into chemical bond energy It takes place in organelles called chloroplasts 6C02 6 H20 solar energy C6H1206 602 Chlorophyll molecules in the chloroplasts trap light energy and start a series of chemical reactions that begin the process of photosynthesis Photosynthesis begins with the split of water molecules H20 which releases oxygen into the atmosphere This process happens only when light is present from there comes the name light reactions of photosynthesis The lightdependent reactions make highenergy molecules of ATP adenosine triphosphate and NADPH nicotinamide adenine dinucleotide phosphate These two types of molecules provide the energy for the next process the lightindependent reactions Another set of reactions occurs independently of light These are called the lightindependent reactions In these reactions carbon dioxide is incorporated into small sugar molecules to make glucose a highenergy sugar Cellular respiration releases chemical energy found in substances The energy released is used by the cell to make biomolecules eg proteins lipids etc and to do cellular work eg movement C6H1206 602 gt 6C02 6 H20 energy released Photosynthesis captures energy respiration releases energy LEVELS OF ORGANIZATION Atoms molecules macromolecules cells tissues organs organ systems organisms FROM SPECIES TO ECOSYSTEMS A population consists of all the members of a species living in a given area tat the same time An ecological or biological community is a system made of species populations living and interacting in the same area 0 Different species populations 0 In the same area 0 Interacting in spatial and trophic feeding relationships Characteristics of the community are species composition diversity stratification and food chains An ecosystem is a community of organisms and the physical environment interacting as a unit ENERGY TRANSFER FOOD CHAINS FOOD WEBS AND TROPHIC LEVELS Photosynthesis is the base of the energy dynamics of an ecosystem how organisms share food resources Biomass refers to the amount of biological material produced in an ecosystem The r 39 quot quot of an is 39 by the amount of biomass produced 0 The primary productivity of an ecosystem is the biomass produced by photosynthesis l o The quot of an y r 39 is the biomass produced by organisms that eat plants or other organisms Energy is passed from organisms that carry on photosynthesis plants algae bacteria to organisms that feed on them and which in turn are eaten by other organisms thus forming a linked feeding series a food chain Food chain refers to the sequence of organisms in a community on successive trophic levels and through which energy is transferred It is a feeding series In a community there are many food chains These chains interconnect to form a food web Food webs are usually very complex involving hundreds of species Trophic level is the position of an organism in the food chain Producers or autotrophs make food from simple organic matter 0 The largest group in a community Consumers or heterotrophs obtain their food by eating other organisms Primary consumers or herbivores eat plants Secondary and tertiary consumers or carnivores eat other animals Omnivores eat both plant and animal materials Parasites scavengers detritivores and decomposers feed at all levels Decomposers or saprobes feed on dead organisms and wastes Material available to saprobes include 0 Dead animals carrion scavengers o Feces and excreted organic compounds detritus detritivores 0 Dead plants logs stumps fallen leaves dead roots detritivores o Overripe fruit Fragments of these materials form detritus The line between scavengers and predators is not always clear 0 Many predators will eat carrion readily 0 Switch from predation to scavenging and vice versa is common Fungi and bacteria are decomposers and completer the final breakdown and recycling of organic materials Without these decomposers fungi and bacteria matter would remain locked up in the bodies of dead plants and animals rather than being made available to successive generations of organisms An ecological pyramid is formed when organisms in a community are arranged according to numbers 0 Producers are the most numerous and are placed at the base of the pyramid o The successive trophic levels decrease gradually There are fewer deer than shrubs less wolves than deer etc Primary consumers are next secondary consumers follow then tertiary consumers follow the secondary etc Rememberthat energy transfer is never 100 efficient Some is always lost before and during the transfer BIOGEOCHEMICAL CYCLES There is a constant recycling of materials matter between the biotic and the abiotic components of ecosystems HYDROLOGIC CYCLE This is the movement of water between ocean atmosphere and land It constantly purifies and redistributes fresh water Physical processes that make it possible are 0 Evaporation liquid is changed to gas vapor o Sublimation change from solid to gas 0 Condensation gas changes to liquid 0 Precipitation falling of water in any of its phases upon the surface of the earth Air can support so much water vapor at a given temperature The Carbon cycle 0 There are two parts to the carbon cycle the atmosphere and the water cycles The Nitrogen cycle 0 Proteins require nitrogen 0 Plants take it the form of ammonia and nitrate o The nitrogen cycle involves the atmosphere and the soil The Phosphorus cycle 0 Phosphorus is a component of phospholipids nucleic acids and other macromolecules 0 Soil solution contains about 3 x 10396 phosphorus but plants contain about 3 phosphorus 0 There are a biotic living and abiotic nonliving portions of the cycle 0 Most forms of phosphate are insoluble The Sulfur cycle 0 Sulfur is a component of proteins enzymes and other compounds o It is rarely a limiting nutrient and is usually absorbed as sulfate
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