📚 Population Density & Limiting Factors — Test Study Guide

Geographic distribution

The area inhabited by a population.

Population density

The number of individuals per unit area.

Growth rate

How populations increase or decrease in size.

Age structure

The ages of individuals in a population and their sex ratio.

Factors affecting population size

Number of births, number of deaths, and number of individuals entering or leaving the population.

Immigration

Movement of individuals into an area, contributing to population growth.

Emigration

Movement of individuals out of an area, contributing to population decline.

Exponential growth

Population growth under ideal conditions with unlimited resources.

Logistic growth

When a population's growth slows or stops following a period of exponential growth.

Carrying capacity

The largest number of individuals in a population that a given environment can support.

Limiting factor

A factor that causes population growth to decrease.

Density-dependent limiting factors

Factors that depend on population size, affecting populations more as they grow larger.

Examples of density-dependent factors

Competition, predation, parasitism, and disease.

Density-independent limiting factors

Factors affecting all populations similarly, regardless of size.

Examples of density-independent factors

Unusual weather, natural disasters, seasonal cycles, and certain human activities.