AP BIOLOGY

Detailed explanation-1: -Population density is the average number of individuals per unit of area or volume. The pattern of spacing of individuals in a population may be affected by characteristics of a species or its environment. The age-sex structure of a population is the number of individuals of each sex and age in the population.

Detailed explanation-2: -The number of individuals living within that specific location determines the population density, or the number of individuals divided by the size of the area. Population density can be used to describe the location, growth, and migration of many organisms.

Detailed explanation-3: -There are 4 main characteristics of the population structure: age, gender, ethnicity, and density. There are 3 main factors affecting the population structure: birth rate, death rate, and migration. The two best ways to measure population structure are censuses and the population pyramid.