POPULATION

Population Estimates World: 7.1 Billion US: 320 Million PA: 12 Million

5 most populous states in the US California: 37 Million Texas: 25 Million New York: 19 Million Florida: 18. 8 Million Illinois: 12.8 Million PA: 12.7 Million

5 most populous countries in the world China: 1.3 Billion India: 1.2 Billion US: 320 Million Indonesia: 250 Million Brazil: 200 Million

1-population: Total number of people in an area

1-population distribution: The world’s population lives in uneven clusters on the Earth. Some places have many people, while other places are empty. Way the population is spread out over an area

1-demography: Science that explains: *how populations change and *why population distribution is uneven.

2- What do demographers study? Rates of birth, marriage, and death.

3-What question do demographers ask? Why people move from one place to another.

4- What are some of the reasons people tend to move? They can live better in a new place. They are forced to move. They cannot feed their families.

5- What did certain regions of the world have that caused them to have larger populations than others? Regions with a long history of farming, good soil, and plenty of water became crowded. These regions still have large populations. Most places that are too cold or too dry for farming still have small populations.

6-What were some of the causes for new population clusters around 1800? Railroads and steamships made it easier for people to move long distances, even across oceans. New jobs in factories and offices meant that more people were living in cities, where they could make a living without farming the land.

7-Population Density The average number of people per square mile

There are more people per square mile than in the countryside. 8-Which has a higher population density, a city or an area in the countryside? Why? The city There are more people per square mile than in the countryside.

9-Birthrate The number of live births each year per 1,000 people

9-Deathrate The number of deaths each year per 1,000 people

10-What does population growth depend on? Abundant food supply Good soil Clean water Waste removal Health Care

11-Look at the graph on page 64:

12-Look at the graph on page 64: A. How do you calculate a country's rate of natural growth? You subtract a country's deaths from its births B. Which of the countries has the highest birthrate? Yemen C. Where is the population growing faster, The US of Zimbabwe? The United States

12-List and explain 2 reasons for rapid population growth after the 1700s? New farming methods have increased the world’s food supply. Scientists have improved important food crops and found new ways to protect crops against insects. Scientists have also found ways to raise crops with less water. Scientists have convinced local governments to provide clean drinking water and sanitary waste removal. These measures sharply reduce disease. Researchers have also developed vaccines to prevent disease and antibiotics to fight infections.

13-Give and explain 3 examples of how rapid population growth puts pressure on all aspects of life. The populations of many countries are increasing so fast that not everyone can find jobs. There are not enough schools to educate the growing number of children. Decent housing is scarce. Public services such as transportation and sanitation are inadequate.

14-Give and explain 3 examples of how rapid population growth affects the environment Forests in many countries are disappearing. People in poorer countries cut down the trees for wood and fuel. Clearing forests causes other problems. In a forest, tree roots hold soil in place, and forest soils soak up rain. With the forest gone, heavy rainfall may wash away the soil and cause dangerous floods. Demand for wood and fuel in wealthier countries also uses up the world’s scarce resources.