GRE Advanced Vocabulary Practice Test 2026 – 400 Free Practice Questions to Pass the Exam

The term "pullulation" refers to a rapid increase in the number of organisms in a population, typically applied in contexts such as biology and ecology. This concept is often associated with organisms that reproduce prolifically or when environmental conditions become favorable for growth, leading to a surge in population figures.

In the context of this question, a rapid increase in numbers is precisely what pullulation denotes, making it the correct choice. This phenomenon can occur in various species, including bacteria, insects, and other organisms, often leading to significant ecological impacts, such as competition for resources or the potential for disease spread.

The other options, while related to ecological or biological themes, do not directly relate to the definition of pullulation. Population control involves managing existing populations, ecological studies focus on the broader relationships within ecosystems, and allergic reactions pertain to immune responses and do not connect to the concept of population growth at all. Therefore, the essence of pullulation aligns specifically with the scenario of rapid numerical increase, confirming that it is indeed the most suitable response.