Limiting factors can result from natural events or changes in human activity.Which of the following situations is an example of a density-dependent limiting factor? A. Hurricane Katrina forced the relocation of thousands of people from New Orleans. B. Increasing greenhouse gases changes the Arctic zone and the polar bear population. C. Populations of deer and rabbit in the Appalachian Forest eat the same plants. D. The BP oil spill in the Gulf of Mexico harmed many of its aquatic organisms. A) B B) D C) C D) A

## Step 1<br />Density-dependent limiting factors are those that have an increasing effect as the population density increases. These factors are usually biological or biotic in nature, such as competition, predation, and disease.<br /><br />## Step 2<br />Looking at the options, we need to identify which one represents a situation where the effect of the factor increases as the population density increases.<br /><br />## Step 3<br />Option A: Hurricane Katrina is a natural event that affects the population regardless of its density. Therefore, it is not a density-dependent limiting factor.<br /><br />## Step 4<br />Option B: The change in the Arctic zone due to increasing greenhouse gases affects the polar bear population regardless of its density. Therefore, it is not a density-dependent limiting factor.<br /><br />## Step 5<br />Option C: The competition between deer and rabbit populations for the same plants is a density-dependent limiting factor. As the population density increases, the competition for resources also increases.<br /><br />## Step 6<br />Option D: The BP oil spill is a natural event that affects the population regardless Therefore, it is not a density-dependent limiting factor.