Understanding Populations and Demography

Ecologists estimate the size and density of populations using quadrats and the ______ methods.

Each population has its requirement for temperature, humidity, food types that determine where it can exist and ______ or not.

Populations can change in their numbers and structure eg age and sex distribution—for various ______.

Most species have limited geographic ______.

No population has individuals adapted to live in all different environments of the earth (eg. polar bears dwell in the ______ region.

Ecologists study populations over time to observe how these populations have changed and predict how they are likely to change in the ______.

Population ranges are not static but change with time, and populations can expand their range when they circumvent inhospitable habitats in order to colonize new ______.

Larger populations are more stable than smaller populations due to possession of greater genetic variability, hence more capability to adapt to changes in the environment through natural ______.

In terms of density, a member of a low-density population where organisms are sparsely spread out might have more trouble finding a reproductive mate than an individual in a high-density ______.

To find the size of a population, ecologists often estimate a population's size by taking one or more samples from the population and use these samples to make suppositions about the population in ______.