Question

which of the following characteristics do population ecologists study?
atmosphere, rocks, water, and living organisms
temperature regulation, nutrition, and metabolism of organisms
composition, distribution, and interaction of species in a given area
number, density, age, and sex of organisms

Explanation:

Population ecologists focus on populations of organisms. They study aspects like the number of individuals in a population, population density, the age - structure of the population, and the sex - ratio. These factors help in understanding population growth, decline, and stability.

Answer:

Number, density, age, and sex of organisms