OCR General Certificate of Secondary Education (GCSE) Biology Practice Exam

Why is crude oil considered an unsustainable resource?

1. It is constantly being depleted faster than it can be naturally replaced

2. It is not used for energy production

3. It is found only in small quantities

4. It produces excessive waste during extraction

The correct answer is: It is constantly being depleted faster than it can be naturally replaced

Crude oil is considered an unsustainable resource primarily because it is constantly being depleted faster than it can be naturally replaced. Crude oil is a fossil fuel formed from the remains of ancient marine organisms over millions of years, and the rate at which we extract and consume it today far exceeds the natural geological processes that would create new reserves. This rapid depletion leads to concerns about energy security and environmental impacts, as the finite nature of these resources will ultimately lead to their exhaustion. The other options do not accurately represent the issues surrounding crude oil. For instance, while waste production during extraction is a concern, it does not define the sustainability of the resource itself. Not using crude oil for energy production contradicts its fundamental role as a primary energy source globally. Additionally, while crude oil reserves can be limited in certain regions, they are not uniformly found only in small quantities across the globe; significant reserves exist in various locations, contributing to their extensive use. Thus, the essence of unsustainability in this context is tied directly to the rate of depletion compared to the extremely long natural replenishment time.