Human Population

Card Set Information

Human Population
2014-04-29 16:18:37
Biology Population

AQA BIOL4 Human population
Show Answers:

  1. What 4 things is human population dependant on?
    • Births
    • Deaths
    • Immigration 
    • Emigration
  2. How do you calculate population growth?
    (Births+Immigration) - (Deaths+emigration)
  3. How do you calculate percentage growth rate?
    change in population multiplied by 100, divided by the population at the start
  4. How do you calculate birth/death rate?
    Number of births/deaths per year divided by  total population that year
  5. How do you calculate the rate of natural increase?
    Births-deaths per year divided by total population per year
  6. What is a population pyramid?
    A diagram showing the age structure of a population with bars denting the percentage of males and females at each age range
  7. What are features of a population pyramid for an MEDC?
    • Narrow base (low birth rate)
    • Vertical sides (low infant mortality rate)
    • Tall height (many survive to old age)
  8. What are features of a population pyramid for an LEDC?
    • Wide base (high birth rate)
    • Sloping sides (high infant mortality rate)
    • Short height (few people surviving to old age)
  9. What is a survival curve?
    A graph showing the lifespans of individuals from a sample group of 10,000
  10. How can the average life expectancy of a population be calculated from its survival curve?
    By looking at the age when 50% of the population are still alive
  11. What is shown by a growth curve?
    The size of a population plotted against time
  12. State 4 social or economic factors that affect the growth of a population
    • Food supply
    • Safe drinking water
    • Effective sewage disposal
    • Effective medical care (vaccinations)
  13. Describe stage 1 of the DTM
    • High stationary: High birth and death rates 
    • High infant mortality and short lifespans due to starvation and disease
    • Population remains low and stable
  14. Describe stage 2 of the DTM
    • Early expanding: Population increased due to high birth rates.
    • Better nutrition and less disease decreases death rates
  15. Describe stage 3 of the DTM
    Late expanding: Birth rate lower due to birth control and less dependance on children to contribute to income
  16. Describe stage 4 of the DTM
    • Low variable: Stable population Low birth and death rates 
    • Greater proportion of old people in the population