Ecology and Ecosystems QBA Exam 1 Practice Test 2026 – Complete Study Resource

The death rate is about how often death occurs in a population over a defined time, not about births, immigration, or net change. It counts the number of deaths that happen in a given period and is usually expressed as deaths per a standard number of individuals (for example, per 1,000 people per year). So, counting how many people die in a year best captures the concept.

Births per time period describe births (birth rate). The number of immigrants per year is about people moving in, not dying. Births minus deaths gives net population change, not the rate of death itself. For context, if 20 people die in a town of 2,000 in a year, the crude death rate would be 20 deaths per 2,000 people per year (or 10 per 1,000).