Question

2.4) when it comes to age structure, describe what happens with different age distributions.
2.5) describe what it means when countries have type i, ii, or iii survivorship.
2.6) define the terms.
a. fertility rate -
b. total fertility rate -
c. replacement level -

Explanation:

2.4: Age structure shows the proportion of different age groups in a population. A population with a large young - age group (pyramid - shaped) has high growth potential. An evenly distributed age structure (rectangle - shaped) indicates stable population size. An age structure with a large old - age group (inverted pyramid) may face population decline.
2.5: Type I survivorship: High survival of young and middle - aged, high death rate in old age (e.g., developed countries). Type II: Constant death rate throughout life (e.g., some birds). Type III: High death rate in young, low death rate in old (e.g., many insects, plants).
2.6: a. Fertility rate: Number of live births per 1000 women of child - bearing age. b. Total fertility rate: Average number of children a woman will have during her reproductive years. c. Replacement level: Total fertility rate needed to maintain a stable population size (about 2.1 in developed countries, higher in some developing due to higher infant mortality).

Answer:

2.4: Age structure shows the proportion of different age groups. A population with a large young - age group (pyramid - shaped) has high growth potential. An evenly distributed age structure (rectangle - shaped) indicates stable population size. An age structure with a large old - age group (inverted pyramid) may face population decline.
2.5: Type I: High survival of young and middle - aged, high death rate in old age (e.g., developed countries). Type II: Constant death rate throughout life (e.g., some birds). Type III: High death rate in young, low death rate in old (e.g., many insects, plants).
2.6: a. Number of live births per 1000 women of child - bearing age. b. Average number of children a woman will have during her reproductive years. c. Total fertility rate needed to maintain a stable population size (about 2.1 in developed countries, higher in some developing due to higher infant mortality).