AP REVIEW – HUMAN POPULATION, INFECTIOUS DISEASE AND GENETICALLY MODIFIED CROPS

POPULATION PYRAMIDS Population pyramids show age structures of different countries. Figure 9-9

POPULATION VOCABULARY  Birth Rate  Total Fertility Rate (TFR)  Replacement Level Fertility  Doubling Time  Zero Population Growth (ZPG)

GROWTH RATE When given population numbers: New-Old x 100 Old When given percentages: Birth Rate – Death Rate + (Immigration rate-emigration rate 10

RULE OF 70 70/ growth rate = doubling time Gives the amount of time it will take for a population to double

Fig. 9-14, p. 183 Birth rate Death rate Total population Stage 1 Preindustrial Stage 2 Transitional Stage 3 Industrial Stage 4 Postindustrial Growth rate over time Birth rate and death rate (number per 1,00 per year) Relative population size Low Increasing Very highDecreasing Zero Negative High

REASONS THE HUMAN POPULATION HAS BEEN SO DRAMATIC IN THE LAST CENTURY The Industrial Revolution Modern Medicine Technology allows us to live in many different areas

POPULATION CONTROL Strategies: Governmental Control Educate women Provide Birth Control Industralization Incentives to have less children Materialism Case Studies: One Child Policy – China Education and Birth Control – India

INFECTIOUS DISEASES

TUBERCULOSIS - TRANSMISSION Transmissible infectious disease – transmitted person to person One untreated person will infect people

TB - PREVENTION Early identification and treatment  Infected individuals have a persistent cough

TB - CURE Treatment with a combination of 4 inexpensive drugs  MUST be taken for 6-8 weeks  Symptoms dissappear within a few weeks  Many people discontinue drugs after symptoms subside  Leads to antibiotic resistant strains of TB  Multi-drug resistant TB strains are now present in 45 countries!

TB - FACTS Recent increase in TB:  Too few screening and control programs  GENETIC RESISTANCE – TB strains are now resistant to antibiotics that used to be effective  Kills 1.7 million people per year  #4 deadliest infectious disease per the WHO (World Health Outlook)

HUMAN IMMUNODEFICIENCY VIRUS/ AUTOIMMUNE DEFICIENCY SYNDROME The HIV virus infects and destroys T- lymphocytes (white blood cells), when the virus is advanced it is called AIDS. AIDS victims die as a result of a severely suppressed immune system

TRANSMISSION Infectious transmissible disease Transmitted person to person by  Sexual contact  Shared needles  Mother to infant Infected individuals may be symptom free for 10 or more years. Even though they do not show symptoms, they are infectious.

THERE IS NO CURE FOR AIDS There is no cure for AIDS

AIDS PREVENTION Do not share needles (better yet don’t do drugs!) Abstain from sexual intercourse or use condoms

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POPULATION ISSUES: WORLD HUNGER

REASONS FOR WORLD HUNGER ISSUES Unequal distribution of available food Loss of arable land Increasing population growth rate Increasing poverty in developing countries

STRATEGIES FOR ENSURING ADEQUATE NUTRITION FOR A GROWING POPULATION: Increase the number of new food crops from a diversity of plant species Distribute food more equitably Increase land are that is dedicated to grain production rather than meat production Assist developing countries in efficient crop irrigation systems.

GENETICALLY MODIFIED ORGANISMS - PROS GMCs use genetic engineering to:  Enhance crop yield  Increase pest resistance  Increase temperature range tolerance of crops  Improve drought resistance  Increase nutrient load of produce

GENETICALLY MODIFIED ORGANISMS - CONS The drawbacks of GMOs are hotly debated. Drawbacks may include:  Increased allergies  Monocrops  Less nutrient loads of produce