An ecosystem is best described by which of the following? a) a population of fish in a small lake b) the wood of a rotting log c) a flock of birds in the air d) an entire desert, including abiotic and biotic factors

The correct answer is D. An entire desert, including abiotic and biotic factors

Explanation:

In biology and ecology, an ecosystem refers to an area or region in which there are both living organisms such as plants or animals (biotic factors) and nonliving components such as water or soil (abiotic factors) that interact and create a complex system through natural cycles. Examples of ecosystems include coral reef or rainforest. This means, an ecosystem needs to include both biotic and abiotic factors, thus, the option that describes an ecosystem is "an entire desert, including abiotic and biotic factors".