Question

guided practice
a species becomes extinct when ______.
a. all its populations die
b. one population dies
c. its ecosystem is disturbed
d. its geographical range is limited

Explanation:

A species is defined as extinct when every single population of that species across all its habitats no longer exists. Losing one population (option B) is local extinction, not species-wide extinction. A disturbed ecosystem (option C) or limited range (option D) does not mean the species is extinct, as populations can still persist.

Answer:

A. all its populations die