Human numbers began a sustained rise about 10,000 years ago. What change most directly supported that rise?

A formerly nomadic group settles near fields and stores harvested grain for winter. Which development allows this community to support more people?

Early farming villages often had more infectious disease than hunter-gatherer bands. What best explains this?

A farming village builds irrigation channels that keep crops growing during a dry season. What population change can this food-system change support?

A community begins raising livestock as well as crops. Which result most directly helps explain a population increase?

During the Green Revolution, high-yield crop varieties were combined with irrigation, fertilizers, and pesticides. What change did this package most directly allow?

A city installs a protected drinking-water system and sewage collection. Which historical population change can follow most directly?

Widespread childhood vaccination becomes available while family size remains high. What is the most direct effect on population growth?

World population rose steeply from the 1800s onward. Which change contributed most directly to that acceleration?

In an industrializing city, water filtration and sewer systems reduce deaths from diarrheal disease. If birth rates stay high, what happens to natural increase?

A country enters the early demographic transition: mortality falls rapidly, but fertility remains high. What population pattern should result?

Why did advances in medicine contribute to twentieth-century population growth in many regions?

A country keeps a high total fertility rate while antibiotics reduce deaths from bacterial infections. Which demographic outcome is most likely?

Mechanized farming and fossil-fuel-powered transport expanded food distribution during industrialization. How could this support population growth?

In a population, infant mortality falls sharply while the average number of births per woman remains unchanged. Why can the total population grow faster?

A population rises from 10.0 million to 10.2 million in one year, then from 10.2 million to 10.3 million the next year. What changed?

A country's annual growth rate changes from 2% to 1% while its population continues increasing. What does the lower rate mean?

Births exceed deaths by 500,000 this year and by 300,000 next year. What does this pattern show?

Look at the annual population-growth-rate graph. Which statement best describes the trend?

A population's annual growth rate falls from 2% to 1%. Using the rule of 70, how does its approximate doubling time change?

A country has a total fertility rate below replacement, yet its total population still rises. What best explains this?

A country has below-replacement fertility, an older age structure, and almost no net migration. Which total-population trend is most likely over time?

A country's birth and death rates are equal, but it receives 200,000 more immigrants than emigrants in a year. Why does its population grow?

Look at the age-structure diagram. If this population reaches replacement fertility now, what can its broad base still cause?

Country A has 100 million people growing at 1% per year. Country B has 10 million people growing at 5% per year. Which adds more people in one year?