Populations
Science

The number of males and females of different ages in a population
Age structure
The number of males and females of different ages in a population. Age structure. Age structure is the distribution of people of different ages within a population, which helps scientists understand population dynamics and predict future trends.

A population changing from high birth and death rates to low birth and death rates
Demographic transition
A population changing from high birth and death rates to low birth and death rates. Demographic transition. It is the process where a society transitions from high rates of births and deaths to lower rates as it develops economically.

A limiting factor that depends on the population size, for example, a large population needs more to hunt
Density dependent factor
A limiting factor that depends on the population size, for example, a large population needs more to hunt. Density dependent factor. In simple terms, a density dependent factor is a natural control on population growth that becomes stronger as the population size increases, like competition for resources.

A factor that limits population growth independent of population size, for example a cold climate
Density independent factor
A factor that limits population growth independent of population size, for example, a cold climate, is a density-independent factor. In science, a density-independent factor affects a population's growth regardless of how many individuals are in the population.

When population growth starts slow, then sees exponential growth, then slows again
Logistic growth
When population growth starts slow, then sees exponential growth, then slows again. Logistic growth. Logistic growth is when a population grows quickly at first, then slows down as resources become limited and carrying capacity is reached.