Unit 3: Age Structure Diagrams

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Questions and Answers

What are the age structure categories?

Pre Reproductive (correct)

Pre-Agricultural

Post Reproductive (correct)

Reproductive (correct)

What age range is considered Pre Reproductive?

Ages 0-14

What age range is considered Reproductive?

Ages 15-44

What age range is considered Post Reproductive?

Ages 45-infinity Signup and view all the answers

What does 'Baby Boom' refer to?

79 million people added from 1946-1964 Signup and view all the answers

What is meant by Slow Decline in population terms?

Manageable Decline Signup and view all the answers

What economic problems can Rapid Decline lead to?

Proportionally fewer young people working, labor shortages Signup and view all the answers

What does it mean when a population is Expanding?

When the amount of pre Reproductive aged people is higher than Post Reproductive Signup and view all the answers

What does Stable population growth indicate?

When the amount of pre Reproductive, Reproductive, and Post Reproductive people are all around the same Signup and view all the answers

In terms of population, what does Declining mean?

When Post Reproductive is higher than Pre Reproductive Signup and view all the answers

List some problems of Rapid Population Decline.

Threatens economic growth, leads to labor shortages, less government revenue, no technology development, no new businesses, raises health care costs, leads to pension cuts Signup and view all the answers

Age Structure Diagrams are simple diagrams showing the age and gender of a population and can be used to interpret growth rates and determine future shift in the __________.

structure diagram Signup and view all the answers

What does a rapidly growing population typically indicate?

Higher proportion of younger people Signup and view all the answers

What defines a stable population?

The age-structure diagram is more triangular, meaning each age group has slightly less than the younger age group. Signup and view all the answers

What characterizes a declining population?

Lower numbers of young people compared to middle and old age individuals Signup and view all the answers

What are Demographic Pyramids?

Pair of back-to-back Histograms that displays the distribution of a population in all age groups and both sexes. Signup and view all the answers

What is represented by an Age Structure Diagram?

Graph of the numbers of males and females within different age groups of a population. Signup and view all the answers

What do survivorship or mortality curves show?

The size and composition of a population Signup and view all the answers

Match the following population growth types with their characteristics:

Type One = Low death rates in young and middle age, high mortality in old age Type Two = Constant death rate over lifespan Type Three = High death rate among young, declines for survivors Signup and view all the answers

In an age structure diagram, a broad base signifies __________ growth.

rapid Signup and view all the answers

In an age structure diagram, a narrow base signifies __________ growth.

negative Signup and view all the answers

In an age structure diagram, a uniform shape signifies __________ growth.

stable Signup and view all the answers

What does 'per capita income' refer to?

GDP/population Signup and view all the answers

What is the population change equation?

(births + immigration) - (deaths + emigration) Signup and view all the answers

What does immigration refer to?

Migration to a new location Signup and view all the answers

Study Notes

Age Structure Categories

Three main age categories: Pre Reproductive, Reproductive, and Post Reproductive.
Pre Reproductive: Ages 0-14.
Reproductive: Ages 15-44.
Post Reproductive: Ages 45 and above.

Population Trends

Baby Boom occurred between 1946-1964, adding 79 million people.
Slow Decline refers to a manageable decrease in population.
Rapid Decline can result in economic challenges such as labor shortages and fewer young workers.

Age Structure Dynamics

An expanding population has more pre reproductive individuals than post reproductive.
A stable population exhibits similar proportions across pre reproductive, reproductive, and post reproductive age groups.
A declining population has a higher number of post reproductive individuals compared to pre reproductive.

Rapid Population Decline Issues

Threatens economic growth and leads to labor shortages.
Reduces government revenue due to fewer workers.
Stagnates technology development and hinders new business formation.
Increases healthcare costs and public debt.
Can result in pension cuts and raises in retirement age.

Age Structure Diagrams

Serve as simple visuals to display the age and gender of a population.
Essential for interpreting growth rates and predicting future demographic shifts.
A rapidly growing population typically has a higher proportion of younger individuals compared to stable or declining populations.

Demographic Pyramids

Illustriate age group distributions and typically resemble a pyramid shape in growing populations.
Constructed as back-to-back histograms for each sex, depicting the population distribution across age groups.

Survivorship Curves

Type One: Low mortality rates in young and middle-aged individuals; high rates in old age (typical in humans).
Type Two: Constant death rate throughout the lifespan (observed in some rodent species).
Type Three: High mortality in young individuals, with lower rates for survivors; seen in fish, oysters, and many invertebrates.

Age Structure Diagram Characteristics

Broad base indicates rapid population growth.
Narrow base signifies negative growth.
Uniform shape represents stable growth.

Population Growth Stages

Pre-agricultural periods typically have high birth and death rates.
Agricultural periods see improvements in food production and population growth.
Industrial periods lead to further growth due to urbanization and technological advancements.
Post-industrial periods may experience stabilization or decline.

Key Equations

Per Capita Income: Calculated as GDP divided by population.
Population Change: Determined by the formula (births + immigration) - (deaths + emigration).

Migration Definitions

Immigration refers to the movement of individuals into a new location.
Emigration involves leaving one region to settle in another.

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Description

This quiz focuses on the concepts related to age structure categories, including definitions of pre-reproductive, reproductive, and post-reproductive age groups. It explores demographic phenomena such as the Baby Boom and its impact on population growth. Test your knowledge on these fundamental concepts of population ecology!