AP EXAM

1. AP EXAM More review

2. Malthus vs. Karl Marx • Malthus- human population growth is not always desirable. Human pop can increase faster than food supplies resulting in famine, disease, and war • Marx- pop growth was a symptom of poverty • Social justice for all is solution • Neo-Malthusian’s- humans at carrying capacity • Neo-Marxists-must eliminate poverty • Others-technology will raise carrying capacity

3. Demography • Study of size, birth and death rate and distribution of humans • Highest growth rates in Africa, middle east • Crude birth is the number of live births/1,000 • Crude death rate is number of deaths/1,000 • Growth rate includes immigration and emigration • Replacement level fertility # of children a couple must have to replace themselves • Total Fertility Rate- # of children born to a an avg woman during her lifetime • Infant mortality rate-# of infants that die prior to one year old • Zero Population growth- pop is no longer increasing • AIDS is i altering age structure

4. Family Size • Younger marriage = more likely to have more children • Educational opportunity results is postponing marriage • Family planning and birth control important • Pension availability important- children expected to care for parents • Religion is a factor • Culture • Women rights vs. Women as property

5. Graying population • Large voting base may alter elections • Difficult to advance in jobs • Fewer workers supporting social security • Some countries are encouraging women to have more children

6. US Population • 800,000 immigrate legally • 500,000 immigrate illegally • 1950s Baby Boom at end of WWII • 1980s Echo Boom from baby boomers reproducing • 307,006,550 = US population • California= 37 million

7. Demographic Transition • Preindustrial stage: high infant mortality rates, malnutrition and disease due to lack of sanitation • Transitional stage: decreased death rate due to medicine and sanitation and improved standard of living; high birth rates • Industrial stage: stable death rates, birth rate begins to decrease • Postindustrial stage: population approaches ZPG • Developing country poor need assistance to push into transitional stage

8. Family Planning • China: successful control • TFR from 6 in 1970 to 1.7 • There are drawbacks to program • Disproportionate male to female ratio

9. Human Health • Nontransmissible diseases cannot spread and may be result of poor choices (smoking) • Transmissible/communicable are spread from person to person • Caused by pathogens, • Morbidity is illness • Mortality is death • Chronic diseases (heart disease) are now present in developing countries

10. Emergent Disease • Previously unknown or that have not been prevalent for 20 years • Swine Flu, SARS, avian flu • Spanish influenza pandemic of 1918 similar to avian flu • Ebola, Marburg and dengue have outbreaks • Civil wars in Africa causing people to move closer to uninhabited areas increasing African sleeping sickness b/c tsetse fly

11. Ecological disease • When a disease spreads quickly through animal populations • Scientists concerned about elk and deer wasting disease in N. America and potential spread to humans • Spongiform encephalophathies similar to mad cow disease • Caused by prions and transmitted animal to animal • Antibiotic resistance • on the rise as humans travel • overprescribing or taken incorrectly

12. Toxicology • Study of adverse effects of toxins on living organisms • Disrupt normal metabolic activity • All toxins are hazardous • Not all hazardous materials are toxins • Hazardous • Flammable, explosive, irritating, caustic, induces allergy

13. Immune System • The body will make immune proteins know as antibodies in response to the antigen. When the body is re-exposed to the antigen, the antibodies are released in large numbers. Formaldehyde frequently triggers an allergic response in humans • Found in furniture, carpeting, and particleboard • Can result in sick building syndrome (SBS) • Mold spores, , carbon monoxide, nitrogen oxides, and cigarette smoke also related to SBS • Pesticides and Polychlorinated biphenyls (PCBs) weaken immune system

14. Neurotoxins • Chlorinated hydrocarbons • (DDT, Dieldren, PCBs, and dioxins) • Organophosphate and carbamate pesticides inhibit enzymes that break down neurotransmitter acetylcholine between neurons and skeletal muscle cells

15. Endocrine Disrupters • Include hormone mimics, hormone blockers and metabolic disrupters • Endocrine system functions in conjunction with the nervous system to maintain homeostasis • Male fish are feminized due to chemical pollutants • Alligators in Lake Apopka were severly affected by a DDT spill • DDT seems to interfere with sex hormones b/c women seem to get more breast and vaginal cancers and men have low sperm counts and fertility • Also includes: Dioxns, PCBs, phthalates in some plastics, several pesticides, and most of the heavy metals

16. Mutations • Mutagens induce a change in DNA • Carcinogens cause cancer and many are also mutagens • Teratogens are agents that affect embryonic development, such as drugs or alcohol: radiation; heavy metals; or biological agents, such a Rubella virus • Thalidomide was used to treat nausea in pregnant women, but caused limb deformation

17. Toxins • Soluble in Water or soluble in oil • Water-soluble toxins are more dangerous b/c water is present everywhere • Oil-soluble toxins are able to enter cells much more readily than the water-soluble toxins • Accumulate in fatty tissue in living organisms • Can be inhaled, ingested, or absorbed through skin • Inhaled is most dangerous as lungs absorb toxins due to their structure • Other factors include: age, genetics, and workplace exposure • Some chemicals are nontoxic but your liver converts it into a toxin • Example: is bacon

18. Bioaccumulation vs Biomagnification • Bioaccumulation refers to the buildup of chemicals in the body tissues • Biomagnification increase in concentration of a toxin in successive trophic levels, resulting in predators with highest concentration • Chlorinated hydrocarbons are highly persistent and fat soluble, heavy metals such as lead and mercury are readily biomagnified • Persistent organic pollutants can be biomagnified • Phthalates are persistent • Found in polyvinyl chloride plastic and some deodorants and cosmetics • Endocrine disruptors • Most in US has phthalates in their tissues b/c of their high persistence

19. Top 20 toxins (CERCLA) • Arsenci • Lead • Mercury • Vinyl Chloride • Polychlorinated Biphenyls (PCBs) • Benzene • Cadmium • Benzo(a)pyrene • Polycyclic aromatic hydrocarbons • Benzo(b)flouranthene • Chloroform • DDT • Aroclor 1254 • Aroclor 1260 • Trichloraethylelne • Dibenz(a,h)anthracene • Dieldrin • Chromium, hexavalent • Chlordane • Hexachlorobutadiene

20. Chemical Interactions • Chemicals may have additive response • The effect is the sum of individual responses • Rats exposed to lead and arsenic show twice the toxicity of an exposure to just one of the toxins • Synergistic response exacerbates the response to another substance • Antagonistic response negates the effects of another chemical

21. Measuring Toxicity • Dose is amount of a toxin given to as test subject • Typically, higher dose is more deleterious • Scientists create dose response curves • Threshold level is first dose at which the effects of the toxin first appear • LD50 (median lethal dose): the dose that kills one-half of the test animals or lethal dose for 50 percent in two weeks • LC50: is for aquatic species subjected to lethal concentrations of a toxin in the water surrounding their bodies • LD50 is typically given in mg/kg of body weight • The lower the value of the , LD50 the greater the toxicity • 50 mg or less per kg body weight = TOXIC Listing • Mammals used for testing, but not always able to predict human outcomes. Thalidomide is an example. • LD50 Is for acute studies only • Carcinogens, mutagens or teratogens- any amount could create an increased chance of damage in an individual

22. Undernourished vs. Malnourished • Undernourished means that an individual is not obtaining the number of calories per day • Malnourished means that a key nutrient is missing such as vitamin A • Folic acid linked to neural tube defects • TWO Protein deficiencies: kwashiorkor (just protein) and Marasmus (under and malnutrition of protein) • Results in stunted growth, mental retardation, and weak immune systems

23. Food shortages • Famine • Food shortages, starvation, social upheaval and economic turmoil • Increased migration to refugee camps

24. Types of food • Three major types: Corn, Rice and Wheat • Also potatoes, barley, oats and rye • Fruits and vegetables small part of human diet • 60% of all meat is raised in developing countries, but they consume only 1/5th • Feedlots associated with high water and air pollution • Nitrates, fecal bacteria and hydrogen sulfide • Animal wastes stored in large lagoons (breached in bad weather) • Increased infections and therefore resistance

25. Seafood • Accounts for ~15% of all animal protein ingested by humans • World’s fisheries suffer from overfishing and habitat destruction • Harvest • Funnel-shaped trawl nets: shrimp + benthic species • Trawl net: drag net through water forcing fish to the end of the net • Long-lining: shorter hooked lines attached to long fishing line (sometimes miles) • Gill nets: vertical nets that fish swim into and gills stick • Bycatch: nontarget species caught while fishing • Dragging trawl kills bycatch • USFWS: long lining threatening seabirds • Turtles trapped in trawl nets w/o TED (turtle exclusion device)

26. aquaculture • Growing aquatic species for consumption • Dramatically decreases deaths of nontarget species • Tilapia and catfish reared in inland ponds • Coastal fish farming can destroy estuaries and mangrove swampls • Crustaceans farms(shrimp, lobster, oysters + clams) • Fish ranching raises fish to be released in the wild

27. Farm Policy • Many countries subsidize farmers in food production • US subsidizes corn, wheat, cotton, rice and peanuts • Subsidies cause surplus and farmers can sell the crops cheaper than they cost to produce • In developing countries US subsidized food is cheaper than local food • 2005 World Trade Organization illegalized American subsidized food

28. Green Revolution • Refers to development of high-yield crop plants • Derived from breeding through years of careful cultivation • Require optimum levels of fertilizers • Transgenic organisms or GMO: contain genes from another organism • USDA concluded that transgenic foods are as safe as unaltered foods so they do not require label • Benefits include higher yields, genes from any species may be used, and toxins might be removed and resistance to stress and herbicides • Now resist Roundup resulting in a decrease in erosion • Research indicates that it is unlikely for the genes to enter wild strains of the crops

29. Transgenic • Bacillus Thuringiensis (Bt) gene added to plants that kill caterpillar and beetle larvae • Goats modified to secrete various products in their milk • Animals modified to grow more quickly on less food • People are concerned about GMOs • Bt toxin might damage monarchs • Allergies • Patenting organisms • Genes can not be made, it must exist in another organism

30. Soil • The weathered portion of the earth’s crust that can sustain life • Young soils are not leached of their nutrient • Older soils are leached and have little organic material remaining • The parent material of soil is rock broken down by chemical and physical weathering • Humus is the dark-colored organic material that remains after decomposition of leaf litter, droppings, and plant and animal remains • Leaching is when minerals or matter is dissolved in water percolating downward • Zone of illuviation is the area in the deeper levels of the soil where the leached matter is deposited • Illuvial material includes iron; humus and clay depending on soil

31. Soil Organisms • Include bacteria and fungi (function as decomposers) • Algae can be present on surface of soil • Round worms (nematodes) and segmented worms assist with aeration • Insects (ants), roots, snakes, gophers, groundhogs and moles all tunnel and aerate soil

32. Chemical Properties of Soil • pH of the soil should range between 6 and 7 for most plants • At low pH: aluminum, iron, boron and manganese are more soluble and more available to plants (Al can be toxic if too much) • Add ground sulfur or aluminum sulfate to increase acidity • Alkaline soil: potassium, iron and manganese are less available • Add lime: to make soil more alkaline • Plants require nitrogen, potassium, phosphorus, calcium, magnesium, and sulfur • Limiting Factors: nitrogen and phosphorus • Humus important for nutrients, water holding capacity, aeration capacity, allowing root growth and increasing porosity of the soil • Salinity can be a problem, especially in irrigated areas