In the context of factors limiting population growth, which condition is most likely to cause a population crash?

• A. A stable environment with low competition and abundant resources
• B. Increased genetic diversity caused by immigration into the population
• C. A steady increase in carrying capacity due to habitat expansion
• D. A sudden depletion of a critical resource (e.g., food) leading to increased mortality

Answer: (D)

Verified step by step guidance

1. Understand that population growth is influenced by limiting factors, which can be density-dependent (like competition, predation, disease) or density-independent (like natural disasters).
2. Recognize that a population crash occurs when the population size rapidly declines, often due to a sudden and severe change in environmental conditions.
3. Analyze each condition: a stable environment with abundant resources usually supports steady growth; increased genetic diversity generally enhances population resilience; a steady increase in carrying capacity allows population growth over time.
4. Identify that a sudden depletion of a critical resource, such as food, causes immediate stress on the population, leading to increased mortality and a rapid decline in population size.
5. Conclude that among the options, the sudden loss of a critical resource is the most likely cause of a population crash because it directly limits survival and reproduction in the short term.