Biology Regents Practice Exam

What factors characterize the unusual environment where bacteria and clams were discovered in Antarctica?

1. High biotic factors controlling population size

2. Presence of green plants

3. Limited sunlight and extreme cold temperatures

4. Availability of specific nutrients in the water

The correct answer is: Limited sunlight and extreme cold temperatures

The unique environment in Antarctica where bacteria and clams were discovered is characterized by limited sunlight and extreme cold temperatures. These conditions create a specialized habitat that many organisms must adapt to in order to survive. Limited sunlight means that photosynthesis is significantly reduced, which affects the types of primary producers that can thrive there. Given the extreme cold temperatures, organisms in this environment have developed specific adaptations for survival, such as antifreeze proteins or cellular structures that protect against freezing. In contrast, the other factors mentioned, like high biotic factors controlling population size or the presence of green plants, do not typically apply to such extreme environments, as the lack of sunlight restricts plant growth. Similarly, while certain nutrients might be available, it is the combination of minimal sunlight and severe cold that defines the unique challenges and adaptations of life in these Antarctic conditions.